117 Advanced Bicycle Repair Tips, Tricks and Techniques
Copyright 2018, Jeff Napier
In this section you’ll discover tools you can buy, tools you can make, best practices, and unexpected way to use tools.
The drill press becomes especially versatile with a cross-slide vise like the one pictured below that you can get from MSC Direct for $60 at the time this book was written. Cross slide vises can be had for as little as $35.
With this, you have a shaper, vertical mill, even a lathe. To use this rig as a lathe, rotate the work piece in the drill press chuck, and press a cutting tool against it with the vise. To get tricky, you can mount the vise sideways, so you can cut along the axis of the workpiece. You may also need to get inventive to make adapters to hold your workpiece in the chuck.
When looking at purchasing a drill press, you want a tall work area so you’ll have room for large work pieces or a cross slide vise. You’ll want extremely variable speeds, especially slow ones. Finally, you’ll want a sturdy press, to eliminate chatter or flex that could reduce your precision.
An oxy-acetylene welding set is a good investment. The gas welding rig is generally less costly than shielded electric welding equipment, and much more versatile, especially since heating and brazing are often a big part of bicycle work.
You’ll want thin hoses and a small handset to do the precision work that bicycles require. Tank size can also be small, saving cost, since in the bicycle business, small quantities of oxygen and acetylene can last a long time.
You may find that the gas welding equipment is far more versatile than expected. Not only can you do actual welding and brazing, you can make your own tools, and you can heat and cut bicycle parts. Stuck bolts, pedals and cranks often respond well to heat. A bent Ashtabula crank can be impossible to remove. Cutting off the left side with a torch takes only a matter of seconds.
Gas welding can be dangerous in untrained or unthinking hands. The heat from the flame can set things on fire even two feet (60 cm) away, including humans. Dirty rags and puddles of lubricant, which are often found in bike shops, are easy to set on fire. Make sure only trained personnel use the welding equipment, and that you have adequate fire suppression equipment nearby.
You might also like to invest in a 4″ also known as 4-1/2″ disk grinder, and sometimes called an “angle grinder,” like the one pictured below. This one is from Harbor Freight, currently being sold for $15.
This is another one of those tools that you’ll use daily to do things like reprofile sprocket teeth, remove locks, and repair your tools.
You may believe that a power tool for $15 is going to be inadequate. I have used one of these very cheap tools for years, and it works fine. One could spend much more for the same thing with a name brand, and end up with a tool that’s not noticeably better.
This is also true of plug-in electric drills. Of course you’ll want one that can accommodate bits up to 3/8″ (10mm), and variable speed reversible. These can be had for under $30, and work just fine.
Cordless drills in the very inexpensive range tend to be low-powered, and have short battery lives, but for many bicycle repair operations, they’re completely useable. Furthermore, you’ll find that the time spent dealing with something that has to be plugged in is wasteful.
Don’t be afraid to stretch the use of your drill. You’ll find a wide variety of accessories makes life easy such as buffing wheels, mounted grinding points, and sideways cutting bits. You’ll even find an accessory for sharpening drill bits.
Perhaps one of the best places to spend more than the minimum amount for a tool is in a good set of drill bits. A set ranging from the smallest size you can imagine up to 1/2-inch (12 or 13 mm) will do nicely. Inexpensive bits not only don’t cut well right from the start, making it impossible to drill through anything but the mildest steel, but they dull quickly. Some even snap or chip at the slightest provocation.
When drilling, you’ll find that certain techniques help.
Except for small diameter holes, a slower drill speed than you might like will generally cut faster, and save the bit from overheating.
Press firmly and steadily. Place your body over the top of the drill when possible, so your eyesight is aligned and you can know you’re drilling straight.
If the bit isn’t cutting, don’t press harder. Sharpen it instead.
Drill a small hole first, then follow up with the full size you want.
If your small ‘pilot’ hole is off center, drill sideways to straighten it out right at the beginning. If you try to straighten it out once you’ve attained some depth, it will be much harder to guide it to where you want.
Speed up the drill when the bit is about to cut through, and press very lightly, so the bit doesn’t jam on the last bit of metal. Although it can be tough on a drill bit, you can reverse the drill for the last little bit before you break through. That will keep it from jamming.
Use a centerpunch to start your hole. This is a small, hardened, chisel-like tool that makes a conical depression. The drill bit won’t wander out of the depression. If you don’t have a centerpunch, a nail will do just as well except in hard steel.
When drilling steel, you might find a drop of cutting oil useful. This spreads the generated heat, protecting the bit from overheating, and lubricates the cutting action.
When drilling plastic, experiment with differing speeds, generally slow ones, to prevent the chips from melting and freezing, which can cause problems ranging from eccentric holes to frozen and even broken drill bits.
Whereas a bench grinder is also a good workshop tool, and serves different purposes, you’ll find the disk grinder more useful. The bench grinder is good for sharpening and modifying your tools, for quickly creating tool modifications, as well as making some bike parts fit that are otherwise too tight.
This bench grinder, from Harbor Freight is currently being sold for $50.
Through experience, I have discovered that an eight-inch bench grinder gets things done significantly more quickly than a six-inch version, generally having more power.
Some bench grinders come equipped with small holders for water or oil so pieces can be frequently quenched to avoid building up too much heat. Since any old can or jar will do, this is not a feature worth spending money for. On the other hand, you’ll want good quality guards and tool rests. Keep your toolrests as close to the stones as possible. You don’t want your workpiece to suddenly slip between the toolrest and the stone.
Mechanics over the years have often injured themselves by not holding small workpieces adequately while using a bench grinder. You may find the heat suddenly transfers to your fingers or thumb, resulting in a blister. Worse, the piece may fly out of your grasp, once around the wheel and its enclosing guard and then right toward your face at 100 miles per hour (160 kph). So, hold workpieces suitably, such as in Visegrips, and work slowly and carefully. This is even more the case when using brushes rather than grinding stones.
If you have ever dropped or chipped a grinding wheel, discard it immediately. If one of these flies apart in use, it can cause a major injury.
Old wire brushes mounted in your bench grinder may start throwing bristles after a while. These don’t generally cause injury unless you’re not wearing eye protection, but they will make you cuss.
Speaking of injury, many bicycle mechanics don’t realize how inconvenient a small chip flown into an eye, or a burned finger can be until they experience it for themselves. Take my word for it. Always use ear, eye and skin protection.
One of the smallest investments you can make is a circular spoke wrench. This little gem saves you the time of finding the right spoke wrench for the wheel you’re currently working on, although almost all bicycle spokes have 15 gauge or 14 gauge nipples. It has enough heft, and is of the right ergonomic shape that once you get used to it, you’ll find this becomes one of your favorite tools. You may want to grind notches in the edge to quickly identify the 15ga and 14ga slots by feel.
Are you one of those people who feel using a ‘crescent’ wrench, more properly called ‘adjustable’ wrench is ‘unprofessional?’ You may want to rethink that philosophy. Here’s why: You can leave your thumb on the thumbwheel most of the time you use the wrench, and every time you place the tool around a nut or bolt, you can with a simple flick, close the wrench for a perfect fit. Then, at the end of the stroke, you flip the wheel the other way, and the wrench opens, making it easy to quickly reposition. With just a little practice, this becomes second-nature and very rapid. Ultimately, you have an open-end wrench that fits better than specific-sized wrenches. Furthermore, it is always directly available. You don’t have to search for that 9mm wrench. Hmmm, now where did I put that?
The ideal size for bicycle repair is 6-inch or 15-cm. Your author made a loop on his belt, and carried an adjustable wrench in that loop for years, saving what turned out to be countless hours that would have otherwise been spent finding the ‘right’ wrench.
The adjustable wrench isn’t a complete replacement for wrenches. You’ll still want box-end wrenches for particularly tight, or hard-to-reach nuts and bolts. But that gets back to the problem of keeping track. During a busy workday, you’ll find your wrenches don’t always spend their time neatly organized on a pegboard. Often, you know that you want a 10mm wrench, but it is hard to see whether one you’re looking at on the bench is a 9 or 11 mm. The answer: Color coding!
Most people do this quickly and easily with colored electrical tape, like this kit you can buy from Ace Hardware for $4.
Your author labeled his wrenches and sockets from 8mm to 19 mm for years with the following four repeated colors, but of course, you can use any colors you want:
Cone channellocks: First, I have to explain my poor terminology. “Channellocks” are a specific brand of tongue and groove pliers. However, many people today refer to any tongue and groove pliers as ‘channellocks.’ This is similar to the way that Crescent, who first made the style of adjustable wrench we call ‘crescent wrenches,’ became the common usage name of the tool.
Anyway, what I’m talking about is taking any medium size quality tongue and groove plier and applying it to your bench grinder until the jaws are as thin as cone wrenches. You’ll find this is a quick and dirty tool for adjusting hub bearing cones. You’ll also find it useful for many other operations around the shop.
Another place to spend more than the minimum is with screwdrivers. You’ll want all the standard sizes and types, with the most common being a #2 Philips. This screwdriver may seem large for bicycle applications, but oddly, with the Philips design, the fit isn’t so much about size as the shape. Cheap screwdrivers don’t hold up well. As the tips become worn or misshapen, they’ll slip, and even sometimes ruin bolt and screw heads. Better quality screwdrivers also have better quality handles that won’t hurt your hands as you try to work with a frozen screw.
Just in case the need ever arises, you may want to purchase the largest variety of 1/4-inch hexagonal screwdriver tips you can find. For various bicycle applications, as well as other things that may happen in your shop, such as upgrading your computer, you may want a full range of Torx, Allen, and other configurations.
The hacksaw finds frequent use in a bike shop. Getting a good frame is essential, since the cheap ones allow the blades to slip and wiggle, which makes clean sawing difficult.
Even more important than the frame is blades. The cheap ones shatter or lose teeth, or simply can’t cut well. Not only is a shattered blade annoying, it can be downright dangerous. Make sure to get 12-inch blades. You’ll find that lends to a natural cutting rhythm that the 10-inch blades are too short for. Press lightly down on the forward stroke only, and use as much of the blade as you can. The inexperienced sawyer takes short rapid strokes, becoming tired quickly, and wearing out the blade too soon.
By the way, you may be like most people in that you don’t know the difference between a screw and a bolt. “Wait,” you say, “Of course I do. A screw is turned with a screwdriver and a bolt is turned with a wrench. Right?”
Sorry, wrong! A screw cuts its own threads in the thing to which it attaches. Screws are generally used with wood, plastics and sheetmetal. Bolts, on the other hand, have matching threads in the item to which they attach, such as a nut or a pre-threaded hole in a metal component.
There’s not much more satisfying than taking powerful, effective strokes with a 14-inch flat file, sometimes also known as a rasp. You’ll find yourself using this tool frequently in the bicycle business, especially if you do custom work. Trying to do the same thing with a little 10-inch or 12-inch file would be frustrating.
You may also enjoy a large rat-tail file for removing metal in non-flat situations. Finally, a few smaller files will find occasional use.
Having a large vise fastened to a sturdy workbench that is bolted to the floor is a great asset in a bike shop. Ideally, the table will be lower than a typical workbench, to accommodate the height of the vise itself.
Your author rigged up a vise with a longer handle, a thumb set screw that would allow the handle to be locked in the middle, and large steel balls at either end. The center lock, and the weight of the balls allowed for spinning the handle, to quickly close or open the vise.
An air compressor is also valuable. It is not essential to a bike shop, and may be one of the later things you’d invest in. First, you want customers, then you want inventory. Only then should you focus on tools you can do without. However, when the time comes, your author recommends a compressor capable of at least 150 PSI (pounds per square inch). That’s the maximum pressure the compressor will reach. Because the compressor cycles between a lower pressure and the max pressure, you’ll want a maximum pressure in excess of any tires you’ll be filling, so that when the compressor is at the low end of its cycle, there’ll still be the pressure you need. Volume is less important. That’s how many cubic feet per second (CFPS) that your compressor can deliver. That’s because most bike shop operations do not use great amounts of pressure. That’s more for painting, sandblasting and filling motor vehicle tires. However, if you do painting, a bigger compressor will be needed.
Unless you can hide your compressor in a basement, another room, or outside the building, you’ll want to make sure it is a fairly quiet one.
Many bike mechanics use workstands, also known an ‘repair stands.’ The most common ones are made by Park Tool Company. The quality and cost vary considerably. You’ll want one that’s sturdy enough and with a big enough base that it won’t wobble or fall over. You may want to bolt it to the floor.
An interesting alternative is ropes, chains or cables hung from the ceiling. At the lower end of the ropes are padded hooks. The ropes should be attached to the ceiling about eight feet apart.
You normally hang a bike by putting one hook around the handlebar stem, and the other under the seat. Ideally your ropes will be easily adjustable, so you can vary the height of the bike to suit your preferences.
The disadvantage with ropes is that the bike is not solidly held. It can swing back and forth. This is easy to get used to, and soon the problem is entirely forgotten. The advantages, besides much lower cost, are that you can access the bike from both sides, and are very unlikely to damage the bike.
Workstand clamps can easily damage paint. Some can even squish frame tubes.
If you do use a workstand, the best bet is to mark, then raise the seat pillar so the bike can be held by that, rather than a fragile, painted frame tube. Don’t forget to lower the seat back down to your mark when finished, or you’ll get some surprising comments from your customers!
Your author had five workstands in his first bike shop that were practically deadly. Manufactured by park many years age, these things had pneumatic jaws. When the mechanic stepped on a pedal, the jaws would close around a seat pillar. These things were very convenient, since you didn’t have to adjust the jaws with one hand while holding the bike with the other. But they had two problems.
If a tool as small as an 8mm wrench dropped onto the pedal on the floor, the bike could be released. Your author once did just that and discovering that the bike was falling, he quickly reached out to catch the bike, grabbing it, unfortunately, by the chainring, which punctured his hand in a neat row of holes spaced a half-inch apart.
The other problem is that if a mechanic were to get a hand pinched in the jaws, which would be easy to do, it could be crushed. Fortunately, that never happened. It is easy to understand why Park discontinued these workstands.
Dremel Tool: This is also known as a 1/8″ grinder, or sometimes “die grinder.” You probably won’t use it often, and when you do, you may find the tool cuts too slowly. On the other hand, a 1/4-inch die grinder can be quite useful. These are available as air-powered or electric tools. The air-driven ones are much less energy efficient, but light in the hand and therefore easy to control. The electric ones have a heavy rotating armature that creates so much gyroscopic force that precision control is difficult. 1/4-inch die grinders usually have a chuck accessory so they can be used with 1/8″ Dremel and other accessories. Mounted stones, burrs, brushes and burnishers of all descriptions can be had to accomplish anything from polishing to engraving.
One use to which die grinders have been put is to remove the chrome plating from screws that have a layer of brass underneath, making decorative gold bolt heads. An old classic centerpull brake by Mafac called the “Racer” had such bolts. The bike mechanic with time on his or her hands might engrave the handles of a pocket knife or other items with bicycle logos.
Cleaning parts is a big part of bicycle repair. At its simplest, you can get some non-toxic, non-flammible parts washing fluid, pour it into a shallow pan, then go to work with a brush.
On the other extreme, you can rent a big parts cleaning system from a company such as Safety-Kleen. Their system involves a metal sink that sits on top of a barrel of environmentally-friendly solvent. It has a pump that pours a never-ending stream solvent through a flexible pipe. Periodically, a Safety-Kleen representative changes the barrel of solvent, so your system is always reasonably clean. They have a small machine that barely fits a full-size bicycle wheel. They also have a larger machine in which you can place most of a bicycle. So, for a quick and dirty washing, you can just set the whole bike on the sink, then wash the chain, rear derailleur and sprockets in one messy but efficient operation. The rent for the larger machine is only slightly higher, well worth the difference. Because the sink is larger, it is easy to keep yourself cleaner in the process.
You don’t need to rent from Safety-Kleen. You can get your own sink and solvent. This is a mistake! Cleaning the machine and maintaining the solvent turns out to be time-consuming and undesirable work.
While the machine itself is nice, the process is greatly enhanced with a simple hollow brush at the end of a hose that you can get from Machine Mart, like the one pictured below.
In the past, most mechanics didn’t wear gloves. They spent considerable time trying to get their hands clean at the end of the day, often ending up still dirty, and with chapped skin. Now, most mechanics wear gloves.
You can get by with the very thin gloves such as you can buy at a drugstore. But, you’ll be much happier with gloves that are 9 mil thick that you can get from hardware and tool supply stores. These thicker gloves seldom tear, and can be reused many times.
Your author removes them quickly by turning them inside out. Then, he partially inverts them, places his mouth over the opening, blowing air in, to restore the gloves to their original shape, ready to wear again.
For many years, all the top bikes were made from steel alloys and brazed. Brazing is a process that you might think of as hot gluing, very hot. But not so hot that it crystalizes the steel, and so can be stronger than actual welding.
Even today, a thin springy steel frame is considered by many as superior to aluminum alloy or various composite fiber frames because it returns almost all the energy you put into flexing the frame. Compared to steel, aluminum creates heat and returns less energy when flexed. So, if you want to build or work on steel bikes, brazing is usually the way to go.
The biggest trick in brazing is to keep the temperature of the steel low enough to maintain its strength. Steel melts around 2,100 degrees Fahrenheit, but brass, the alloy most often used in brazing, melts at 1,600 degrees.
Another option, used in the finest lugged frames, is silver brazing, also known sometimes as ‘silver soldering.’ This melts at 1,200 degrees, so is less likely to overheat the steel, but doesn’t have as much strength.
The brazing technique most commonly used in bicycle shops to augment, repair or create steel alloy frames involves an ordinary oxy-acetylene welding set. A slightly larger tip than would be used for welding is used, with a neutral or very mildly oxygenizing flame. Some people use a rosebud tip, which has several smaller flames, to spread the heat.
The frame intersection is brought up to the temperature at which brass will melt, then a stick of brass, called a “rod,” is introduced at an edge. As the stick melts, capillary action sucks it into the gap between the lug and the frame tubing.
Because the brass will not flow over, and will not stick to an oxidized surface, the parts are cleaned just before brazing, and flux is used. Flux is a material that smokes at brazing temperatures. The smoke is harmless to the brazing but keeps the oxygen from the atmosphere away. Flux can be applied in paste form to the pieces to be brazed, as well as a coating on the brazing rods.
Brazing is at its best when flowed between two surfaces. A sandwich of steel, brass, steel is remarkably strong. The ideal gap between the two pieces is 0.020 inch (1/2 millimeter).
Second best is fillet brazing. This is more of a welding process, but done at a temperature below which the steel would melt. You control and build a molten puddle where two steel parts are to be joined. Once cooled, you have a large area of contact built around intersections. With grinders or rat tail files, this can be smoothed to look very appealing, like a vintage Schwinn bicycle.
You can build a very nice and strong lugless frame by starting with pieces that fit well together. The tubes should be mitered nearly perfectly. These can then be flow brazed, so that wherever they are tangent is fastened. That, by itself, would not be sufficient to hold a bike together, so you then build fillet brazing over the flowed brazing for much more area of contact.
Going lugless is the ideal solution for when lugs are not available, such as a bike with unusual components or angles.
This process works well for much more than bicycle frames. It can be used for bicycle trailers, circus bikes, human-powered machines, unicycles, and even bike repair tools.
In making your own tools, ordinary welding is often sufficient. But there are times when brazing is superior, such as when joining hardened metals. If you weld a socket, bit of hex wrench, or knife blade to a handle, welding could kill it. However, when brazed, the steel will not lose its strength.
You’ll find a trick when lighting your torch, and another when shutting it off avoids a big mess. If you light a pure acetylene flame, big fluffy flakes of carbon are formed that float around. When they land, they are hard to clean up.
So, don’t do what so many welders do, which is to open the acetylene valve and light the torch, then add oxygen. Add some oxygen right from the start. Start with what’s called a ‘carburizing’ flame, one that’s mostly acetylene, but the bit of oxygen will eliminate the carbon output.
When shutting your torch off, the same is true. Don’t close the oxygen valve first. Instead, reduce the oxygen, then shut off the acetylene. With practice, you can learn to make a remarkably loud pop when turning off your torch. The pop has a function. It keeps your torch tip clean.
Do not close your torch valves more firmly than necessary. If you do, you can grind ridges in the valves, which makes it hard to adjust the flame.
If you are working with cylindrical tubing, as is often the case in bicycle technology, quality mitering becomes important. If you have a lathe, you can get cutters of the same diameter as the the tubes you want to fit a miter to. Set a tube you want to miter on the tool post, and use the compound rest to set the proper angle. Then just push the tube against the rotating cutter.
You may not have the money to buy large diameter milling-type cutters, let alone a lathe.
An in-between approach is to mount a proper diameter cutter in a drill press, and mount the tube you want to cut on the press’s table.
Better yet, you might enjoy manual mitering. You can take some six-inch sections of soft wood, and cut groves into them, so that you can sandwich them around a tube, and gently squeeze the whole works in a vise.
Then, using the largest rat-tail file you can find, you’ll find you can quickly learn to miter tubes quite accurately. Don’t be afraid to check your work often to make sure you don’t cut too much material.
A bent frame can cause steering, stability, and chain alignment problems. You can perform the following frame alignment checks:
1. Stand so you can see the head tube and seat tube at the same time. They should be exactly parallel.
2. Tie a string from one dropout around the head tube, and down to the other dropout as pictured. The measurement from the string to the seat tube should be the same on both sides. Most frames can be cold set, which means ‘bent,’ so that the dropouts are properly aligned. Bend one side in or out, then the other. Suddenly, a bike that was difficult to ride without hands becomes easy.
In the photos, this is shown on a frame with no components. The test can be done equally well on a fully-equipped bike.
3. You can lay a straight edge against the sides of the bottom bracket, and measure the distances to the seat tube and down tube. An alignment problem here is not easy to repair and can cause driveline miseries. Fortunately, this type of alignment problem is rare.
A quicker version of the test can be done with the crank arms themselves, by measuring their distances to the tubes near the center and again at the outer ends.
If you have a bicycle that’s been in a collision that bent the headtube back, the best bet is to replace the frame. However, some people experiment with bending the headtube back. This can be done by placing a long steel bar in the head tube and applying pressure without heating the frame, called ‘cold setting.’ To avoid distorting the headtube where pressure is applied by the bar, leave the headset cups in the headtube. If it is a type that doesn’t use conventional headset cups, and if the diameter is correct, you can insert temporary headset cups, or create some tight-fitting flanges on a lathe for the purpose.
You may wonder where to get a bar sufficient for this procedure. One common bar is used in conventional freeweight lifting. Another candidate is an axle from a rear-wheel drive car.
The concern with repairing a bike that has a bent-back headtube is that the frame will fracture, generally right at the intersections. Sometimes the fracture is small and you won’t see it. Then, after a hundred or a thousand miles, the frame may fail, possibly injuring the rider.
A brass sleeve can be built around the areas that are weakened. This is done by building up brazing material, keeping the temperature low enough to avoid significant weakening of the steel, but hight enough to get good adhesion. Then, using die grinders or rat tail files, you can optionally file it down, ending up with a smooth look, as you’ll see in the old Schwinn bicycles.
When dropouts are out of alignment, the wheel bearings suffer. Dropout alignment can also affect steering, riding efficiency and cause driveline problems. Fortunately, dropouts are easily checked and repaired. In the pictures below, you’ll see dropout alignment gauges being used. This tool is not necessary. The test can be done equally well with nuts, bolts and flat washers.
A slightly bent fork can make a bike nearly impossible to ride without hands. It will also cause undue waste of energy as the rider works to maintain stability.
You can check a fork for alignment with the following tests:
1. Lay the fork on a flat table with the dropout touching the surface. Lay a straight edge across the back of the fork crown. The straight edge should be parallel to the table.
2. Draw a straight line on a surface. Lay the fork on the surface so that the steering tube is perfectly aligned on the line. The distance from the line to each dropout should be the same.
3. Lay a straight edge against the steering tube. You should not see a gap. Look especially at the front side, where a bend is most likely to be seen.
Many bike mechanics try to align a bent wheel entirely by tensioning some spokes and loosening others. This is useful only for slight bends. Anything more, and the tight spokes are sure to pop before long. Furthermore, a wheel that’s pulling hard against a warped rim is weaker.
You can repair a remarkably bent wheel if you follow these steps:
1. Loosen all the spokes a few turns. Go around the wheel a few times, loosening each spoke only a turn at a time. Start at the valve hole, so you know where to finish.
2. Once all the spokes are loose, find the most bent area, and do your best to assess where the bend starts and ends along the perimeter of the wheel. Put soft blocks under the rim where the bend starts and ends, then step on the bent area, pressing it back into shape. You’ll have to press it beyond the correct amount, since it is likely to mostly spring back. Once the wheel is nearly true, tighten and adjust the spokes.
Keep in mind that most aluminum alloy rims are prone to work hardening. This means that when the metal is bent, it crystalizes, and after being bent severely or a few times, it is likely to fracture, a very dangerous situation in the case of bike wheels.
This is a good technique to know when out on the road, where a bent wheel could otherwise end a ride.
Flat spots are common and annoying, but often repairable. So, don’t throw that flat wheel away!
Keep in mind that most aluminum alloy rims are prone to work hardening. This means that when the metal is bent, it crystalizes, and after being bent severely or a few times, it is likely to fracture, a very dangerous situation in the case of bike wheels.
A mild flat spot can be fixed by loosening the spokes in the area of the flat spot, and tightening all the others.
More severe cases require more severe treatment.
1. Disconnect all the spokes in the area of the flat spot.
2. While holding the wheel in one hand, bang on it hard with a soft mallet held in the other hand, until the flat area now protrudes outward a millimeter or two too much.
3. Reconnect the spokes, and true the wheel in the normal way.
When a bicyclist hits a curb or a pothole with under-inflated tires, or without balancing on the pedals, but instead sitting with full weight on the seat, a rim can become kinked. The repair is so simple you’d think there must be more to it. All you do is hit the kink with a hammer to bend it back into position.
There are a couple of caveats.
Most modern rims are made from an alloy of aluminum. Too much bending of this material can cause a fracture, which in the case of a bicycle wheel can result in a serious letdown.
You can also use large pliers to squeeze the kink back into shape. If you do this, make sure to pay attention to the other side of the rim, so you don’t squeeze it also, resulting in a pressed in area, the opposite of a kink. One way is to offset the pliers so that the pliers press against the bottom bend of the non-kinked side. Another is to place a cloth covered piece of wood under the jaw of the pliers. This is good too, to prevent leaving plier jaw marks on the rim.
Overlong spokes that stick through the top of the spoke nipples will cause punctures. Var and other companies make tools to slice off the top of spokes. These usually don’t work as well as you’d like. A better approach is to use your 4-inch disk grinder on these spoke protrusions. Another approach is to knock them off with a small chisel and hammer.
Hozan, Var and others make spoke threaders. These tools will turn a long straight-gauge spoke into the length you need. The threads are pressed out from the spoke, much like extruding a shape with modeling clay. The tool is too slow and inaccurate to make a full set of spokes, but is good to manufacture one spoke in a pinch.
Two roadside repairs for spokes are worth mentioning:
1. If you need to replace a broken spoke, but don’t have one of the right length, you can use a longer one by bending an l-shape in it, like pictured below. This will work as well as a spoke with a proper head.
2. You can hook a spoke into a nearby crossing to help support a rim.
You may find that spokes start breaking on the right, freewheel, side of a rear wheel. This indicates fatigued spokes. Those that have not broken will soon, so all spokes in that wheel should be replaced.
A quick way to diagnose wheel problems is a pinch spoke check. Turn the wheel around and with one hand on each side, squeeze each outermost spoke crossing. The spokes should all be about equally flexible. This will quickly identify loose and broken spokes. The experienced technician can also feel overly-tight spokes.
More than once, your author has seen beginning bike mechanics make a big production out of truing a wheel. The mechanic will remove the wheel from the bike, remove the tire and tube, then place it in a truing stand. This is not necessary for minor adjustments, as long as you trust that the rim strip is in good order. Simply leave the wheel on the bike, and use the brake pads, or a cable tie temporarily applied to a fork blade or seat stay as an indicator showing where the wheel needs to be trued.
Using tire levers, you run the risk of puncturing the inner tube. In most cases, there is no need to use tire levers. Instead, after removing all the air from the wheel, step on the wheel with both feet as shown in the picture. The valve can be anywhere but at the top of the wheel. Lift up on the tire and tube at the top, then press sideways over the edge of the rim. With mountain bike tires, this is very quick and easy. With some of the thinner wheels, this process is more difficult. With practice it is amazingly easy.
Installation without tire levers is even easier. Put just enough air in the inner tube for it to take its donut-like shape. Feel around the inside of the tire in case a puncturing object is still stuck in the rubber. Do this carefully, so you don’t puncture your fingers if you find something.
Lay the tube into the tire, then insert the valve stem partially into the valve hole in the rim. Slip the far side of the tire entirely onto the rim with your thumbs or fingers, starting at the valve, and working with both hands to the opposite side. The tire should slip over the edge of the rim more easily than you’d expect.
Repeat the process for the close side of the tire. Make sure you haven’t put too much air in the tube.
Push the valve down into the tire momentarily to make sure a fold of inner tube isn’t caught under an edge of the tire. Then pull the valve out of the hole to its full extension.
Put only a small amount of air in the tire, then inspect the tire all the way around, on both sides, to make sure it is all seated properly. Bring the tire up to its full rated pressure, as shown in vulcanized print on the side of the tire.
While there are new glueless patch kits on the market, most don’t work as traditional cold contact cement patch kits. Even fifty years after they have existed, many people don’t know how to use these properly. They try to light the glue on fire. It doesn’t work that way. Others will apply the patch before the glue is dry. That makes sense, since that’s the way most glues work. But not patch glue. It is a contact cement. It sticks best when fully dry.
So, find the puncture. Remove the oxidized outer layer of rubber with sand paper, not the metal scraper included with many patch kits. That thing can cause more holes. Apply glue over an area larger than the patch will cover. Let it dry fully. Then remove the backing from the patch, being careful not to touch the surface, which would contaminate it. Apply the patch over the hole, and press it on firmly. Voila, you’re done!
You don’t see many sew-up tires, also known as ‘tubulars’ these days. They are still incredibly light and efficient. These tires don’t clinch onto the rims. Instead, they are glued on. The inner tube is sewn entirely inside.
Some sew-ups can be incredibly tight when new, being almost impossible to stretch onto a rim. You can step on these, then pull up to stretch them several times before installation.
Sew-ups can be patched much like ordinary inner tubes. First you must identify the location of the hole. Inflate the tire, and set it in a bucket of water if you don’t hear where the air is coming out.
Peel away a portion of the tape on the inner side of the tire covering the course threading that binds the edges together around the inner tube. Cut these coarse threads with a small pair of scissors. Cut only enough to access the puncture. Apply a patch as described above, then using thick canvas thread, re-sew the tire around the tube. With practice, you’ll know how tight to make the stitching. Too loose, and the tube could bulge between the threads and wear a new puncture. Too tight, and the tire will be narrower in that area. You’ll find an ordinary needle, even a large one, is hard to push through the original holes in the tire casing. You’ll find that a triangular needle works better. Rather than pushing the needle through with your fingers, or even with a thimble, grasp the needle with pliers.
For best results, adjust derailleurs in this sequence:
1. Shift the chain onto the largest front sprocket.
2. Shift the rear derailleur to the smallest sprocket. Check the cable tension. If it is loose enough that you can flex the cable back and forth in the open stretch along the down tube more than 1/2-inch, loosen the anchor bolt, pull the slack out of the cable, then retighten the anchor bolt.
2. Turn in the limit screw on the rear derailleur until it can no longer shift onto the largest sprocket. Back off the screw, to just where shifting into the large sprocket is quick and easy.
3. Adjust the high gear limit screw so that the derailleur no longer shifts onto the smallest sprocket. Then back off until it shifts into high gear easily.
4. Repeat the process for the front derailleur. Keep in mind that the outer edge of the front derailleur should be a few millimeters above the largest chainring, and that the front derailleur cage should be parallel with the chainrings.
5. Adjust the index shifting with an adjusting barrel at the shifter or the derailleur until the shifting is as clean and correct as you can manage.
6 Test ride the bike to be sure your settings are correct under the pressure of actual riding.
If shifting isn’t clean, you might first check that the cables are working freely. If shifting is still not good, it may be because the chain or sprockets are worn. Other possible causes are a bent dropout, bent derailleur or loose pivots. If any of these are the case, then all the adjusting in the world won’t help. Furthermore, if you actually get a worn or damaged system to shift properly, it will probably fail in short order. So, parts replacement is usually required to get things working right again.
However, there are some things you can do. You can bend the tips of the front derailleur cage inward to more closely focus the position of the chain. You can bend the middle portion of the cage outward to prevent rubbing.
If a chain wants to fall off a chainring or the largest rear derailleur sprocket, you can spin the sprocket against your disk grinder, or a large flat file held at an angle, reshaping the teeth to an angle that’s more likely to hold the chain. This takes practice, and is not recommended unless you have replacement sprockets handy.
If the chain falls between chainrings, they are bent, the spacing is too wide, or one is install backward. Bent chainrings can be bent back with judicious hits with a hard mallet. Be careful not to hit the teeth.
If a chain skips, the diagnosis is surprisingly easy:
If it happens once per revolution of the chain, you have a stiff or damaged link.
If it happens once per revolution of the chainwheel, you have a problem there. This is rare.
If it happens once per revolution of the rear wheel, you have foreign matter stuck between the sprockets, or a defective sprocket tooth.
Most chain skipping is random. This is usually caused by a worn chain and smallest rear sprockets. They wear together. As the chain lengthens, great pressure is applied to the sprocket teeth, since the chain no longer contacts them all concurrently. Now, all the load is applied to one tooth at a time, and so the sprocket will wear to match the chain. However, the chain will continue to lengthen as the pins and bushings in the links wear.
You can measure a chain for wear. The links have to be exactly 1/2-inch apart. It is hard to see this wear in one link, but twenty four links should be exactly one foot long. Anything visibly beyond that, and the chain is worn out.
On some modern bikes, the sprockets are made of such durable steel that wear is slight, so only the chain needs to be replaced. On many bikes, when you replace a chain for wear, you have to replace the freewheel, or at least its smallest sprockets as well, or the problem only gets worse.
The good news is that the chain wear problem progresses slowly, and is only noticeable when pulling hard against the smallest rear sprockets.
Chains should be periodically checked for damage. They usually break only when under the greatest load, such as pulling hard up a hill. This can be a serious let down for a rider who is not expecting a sudden loss of resistance.
Ideally, you can clean a chain, then visually inspect both sides of every link. This is not easy, so a quicker inspection may suffice. Looking at the top of the chain as you turn the crank backward, watch the chain go by. You should not see any link pins sticking out one side or the other farther than the others. If you do see such a link, consider replacing the whole chain. It is likely that whatever caused the slipping pin will happen to other links as well.
The three most common types of cranks are cotterless, Ashtabula, also known as ‘American,’ and cottered.
You seldom see cottered cranks any more unless you work on antique bikes.
Photo by Flyingdutchman63 [CC BY-SA 4.0, via Wikimedia Commons
These used round pegs, called ‘cotters’ with flat sides that wedged against a flat in the spindle (axle) surface. With time, the crank cotters, which are made from a soft steel could become corroded or distorted. The first effort at removing a cotter should try to preserve it.
1. Loosen the nut, then tap the cotter sharply with a small hammer. Ideally, it will pop loose. You can remove the nut, and the cotter will fall out.
2. If that doesn’t work, try tapping directly, but gently, on the threaded end, knowing the threads and therefore the cotter will be destroyed. If it is important to preserve the cotter, you might try penetrating oil, and wait a day or a week.
3. Failing that, use an air impact hammer, described in the next section about seat pillars, or drill a small hole entirely through the cotter. Then follow that with a larger hole, so that a small impact will cause the cotter to collapse inward, and become free. It is important to make sure your hole is drilled through the center of the cotter. If it goes sideways, you could damage the crank or the spindle.
Ashtabula cranks are one piece in the shape of a dog leg. They are made from steel, and so are rather heavy, but inexpensive and common on American-made bikes. Normally, they are removed by disassembling the bearings from the left side. The bearing cone and locknut are left-threaded.
However, these cranks are easily bent when the bike falls over. It is possible that a crank will become so bent that when the bearings are disassembled, the crank will not come out of the bottom bracket shell.
If you believe a crank is too bent, you can remove the pedal, put a long, strong pipe on the crank, and bend it back outward. Since the metal is fracture prone, consider the crank a lost cause, and replace it with a new one.
Another approach is to simply cut the crank off just outside the bearings, with a cutting torch. If heated quickly, and cut smoothly, no damage will occur to the bearings or the bike’s paint.
The most common type is a ‘cotterless’ crank. These, like the cottered cranks, consist of three pieces, two cranks on a central spindle. (Note that automotive terminology has reversed the usage of ‘axle’ and ‘spindle,’ as used in bicycle nomenclature.)
To remove cotterless cranks, you use a ‘cotterless crank remover,’ also known as a ‘crank puller,’ or ‘crank extractor,’ such as this one by Park Tool Company that you can buy from Walmart.
This tool has a hollow outer threaded nut that engages fine threads in the center of a crank. The threads seem to be there merely to hold a dust cap, but their main purpose is to support the cotterless crank remover. Remove the nut or bolt found under a dustcap that locks the crank to the axle. Once engaged, this outer threaded nut has an inner screw that presses against the spindle. When the inner screw is turned, it presses the crank off the spindle. Ideally. When using a crank remover, make sure the outer nut is fully engaged in the threads so they won’t be stripped.
Sometimes, the threads are too damaged to accept the crank remover. Sometimes, despite your best effort, the crank remover cannot do the job.
If the threads haven’t already been damaged, heat the crank quickly with a large torch flame, being careful not to affect the paint on the bike, then try the tool again. The crank may almost fall off, since heat expands the crank including the tapered opening in the crank where it meets the spindle.
How much heat is right? You want enough to cause the crank to expand, but not so much as to melt the aluminum alloy. Put a dab of grease or oil on the crank periodically as you are heating it. When the lubricant smokes, you are at the right temperature.
A special tool can be purchased that looks like a tapered fork. This tool is applied between the bottom bracket assembly and the crank. It is hit with a hammer and may force the crank off the spindle. When used at room temperature, it often doesn’t work, is awkward to use, and can cause damage to the bearings.
The thing to do is to heat the crank rapidly with a torch, then apply the tool. If you don’t have the special fork tool, you can simply tap on the outside of the crank with a mallet or hammer.
The left pedal is left-threaded, meaning you turn it clockwise as you are facing the bike to remove it.
At first, you might think that pedal threads are traditionally wrong. If a pedal becomes loose, it will naturally unscrew while riding. That’s dangerous. However, if it were the other way, especially if you had foot restraining devices such as toe clips, and the pedal’s bearings were to jam, the pedal wouldn’t unscrew. Instead, your foot would be subjected to tremendous force and you could be injured.
Normally, pedals are tight in the cranks, but a good solid application with a wrench will break them free. If that’s not sufficient, you might tap on the end of the wrench with a hammer. Failing that, a day or longer soaking with penetrating oil if you have it, or a thin oil such as WD-40, may free up the corrosion.
If not, you can heat the end of the crank to expand it, including the threaded hole, then the pedal should unscrew easily. In the case of aluminum cranks, overheating and melting the metal is possible. So, use a torch with a large flame to heat it rapidly, but test by putting a drop of oil on the crank periodically. When the oil smokes, you have reached the maximum safe temperature.
More than once a bicyclist has stripped the pedal threads by letting a pedal come loose, or by trying to put a left pedal on the right side or vice versa. There is a repair kit for this called the Eldi Pedal Tap/Bushing Set, available from Universal Cycles.
This kit contains thin steel sleeves threaded on the inside and outside. It also has some taps, drillbit-like-things, that expand the hole, clearing out the damaged threads, and then rethread the hole to a larger diameter. You then thread a pedal into a bushing, then thread that into the crank, and you have a repair that’s stronger than new. Unless you have a good slow-turning and easy to manage power tool, the best bet is to turn the taps manually. It will be slow going until the threaded portion engages the crank.
These threaded sleeves are sometimes incorrectly called ‘helicoils’ named after the manufacturer of similar threaded sleeves for machine and automotive use.
Aluminum kickstands are usually secured with a steel bolt. Due to its low location and large size, it is prone to water and contamination. By applying grease to this bolt upon installation, you’ll avoid the stuck kickstand bolt problem that is very common in older bikes.
Most aluminum kickstands are universal. They are extra long, needing to be cut to the right length to fit each bike. You’ll find that the amount to remove is fairly consistent with most ordinary bikes.
You could be gentlemanly (or gentlewomanly) and saw it off nicely with a hacksaw. Or, you can clamp the kickstand in a vise, with just the portion you want to remove sticking up above the jaws. Give it a good whack with a hammer to break it off, and your kickstand is adjusted.
One of the best, although not necessarily elegant ways to secure lighting or cyclometer wires, or brake and derailleur cables is with ordinary cable ties. These can be had in a variety of sizes and colors such as these that you can buy from Del City.
You’ll be asked more than once to remove a lock with a forgotten combination or lost key. You might try the big bolt cutters, but cables often fray in their jaws, and some of the bar locks are just too tough. The answer is your handy 4-inch disk grinder. It will quickly remove locks, as well as other large and bulky accessories.
Handlebar grips can be frustrating to remove unless you use one of these two techniques:
1. Blow compressed air against the inside edge of the grip. The air gets between the grip and the handlebar, and the grip will slip off strangely easily. It might even blow off without being touched.
2. Using your cone channellocks or a pedal wrench, lay the tool against the inside edge of a grip, then bang on the tool with a mallet. Make sure to avoid leaving scrapes on the handlebar.
Many chrome-plated accessories, as well as any chrome components can be de-rusted with dry steel wool. Use a fairly coarse grade, and wear gloves. You’ll find that unless the rust is quite thick, it wipes away quite easily, and entirely.
Removing a stuck seat pillar, more commonly known as ‘seatpost,’ can be frustrating if you don’t know these tricks:
1. Soak the accessible area with penetrating oil. Lacking that specific oil, using a thin oil, such as WD-40 will often work. Patience is also helpful. If you can wait as long as a week, the oil may work surprisingly well. You might think that the seat pillar is stuck all the way down, and the oil couldn’t possibly reach the worst area. Actually, the bulk of corrosion happens near the top, where the oil will penetrate.
2. Depending on the design at the top of the seat pillar, and assuming the reason it’s stuck isn’t because the seat pillar was too large in diameter for the seat tube, you might try tapping it down with a hammer first. A mild impact at the top won’t hurt most seat pillars, yet it may break the bonds of corrosion. Then, you can reinstall the saddle, and twist and pull the seat pillar out.
3. Use an air impact hammer. These things, also known as ‘muffler cutters,’ can be had for as little as $10 at Harbor Freight.
The tool is used most often for cutting through sheet metal, but many attachments are available. There is a moving weight inside the tool that rapidly hits an attachment. Some of the attachments are chisels. Others have blunt ends. You’d use a blunt-end tool against the top of the seat pillar to remove it. If the seat pillar is still resistant, or if there is no expanded top, you can use a chisel attachment to cut partially into the pillar, so you can then get a bite on it with a blunt tool. This will ruin the pillar, but save the bike. Your author has never seen a seat pillar in over 15,000 bikes that was so stuck an air impact hammer couldn’t remove it.
The air hammer is great for removing other stuck things as well. For instance, the cotters in old-fashioned cottered cranks were often so corroded, or sometimes physically distorted that the only way to remove them besides drilling, which took too long, was to blast them with an air hammer.
You have probably seen those solid plastic saddles that are the bare minimum bicycle seat. They are usually a bit too hard to be comfortable. Some of those seats can be drilled with large holes, typically 1/2-inch (13mm) in diameter in a pattern. The edges of the holes can then be chamfered (rounded) with a countersinking bit, Dremel tool, or otherwise. For best results, drill only the wide portion of the saddle. Too meany holes near the horn may cause the saddle to fracture. When you’re done, you have a nice-looking seat that weighs less than any other seat money can buy.
More and more, bicycles are using sealed bearings, self-contained units that are press fitted into hubs, bottom brackets, headsets, and even sometimes derailleur pulleys.
The older cone-and-cup style bearings should be manually overhauled periodically to clean out tired lubricant and inspect for damage. This is true even if they are ‘sealed’ since the seals on this type of bearing are less than ideal. The most frequent place you’ll find damage is on the bearing cones. They are case-hardened, so that the outer surface is very durable. However, the outer surface can break away, revealing softer metal underneath. Bearing components in this condition only get worse with time, eventually leaving the rider stranded.
Many components containing these bearings use thin metal cages than rotate with the balls in a group. The cage imparts very little friction, and is there only to make assembly easy. Other cone-and-cup bearing assemblies use loose steel balls. You’d find it frustrating to keep these balls in position while reassembling the device. Therefore, grease is used to hold the bearings in place during assembly. Many mechanics like white lithium grease not only because the lithium particles make a good lubricant, but because the grease is white, it is easy to see that the balls are properly positioned.
All the older style freewheels used what seemed like a thousand 1/8-inch steel balls as bearings. Most actually had 78 balls. These, like bearings elsewhere, should be cleaned and lubricated from time to time. To disassemble an old-style freewheel, bang gently on one of the holes on the top of the core with a small blunt punch and hammer. These holes will turn a plate that is left-threaded, so your goal is to turn it clockwise to remove.
Do this over a rag, as all the bearings will fall out. Clean, then reassemble, sticking the bearings into their races retained by grease. Leave space for one or two balls in each race. Take care of very thin metal shims in the core of the freewheel because they are easily damaged. The freewheel, which normally doesn’t need bearing adjustment, is adjusted by adding or removing shims. In some models, the pawls (flippers) need to be held down with a thread during assembly. The thread is then pulled out. Finally, screw the top cover back on, and set it tight by banging gently with a blunt punch and hammer.
Most rear derailleurs use simple sleeve bearings for the pulleys. These should also be disassembled, cleaned and lubed now and then.
Many bike mechanics have to work with the public when it comes time to assess a bicycle for repair. Some of the mechanics worry about how to handle the situation. They may not know exactly what to look for, and how to present what they find. In many cases, the mechanics miss noticing important problems that the customer should know about before leaving the bike for repair. For instance, if the shop sells a tune-up, without realizing a wheel is so bent that it cannot be repaired, the customer may balk, and you have a ‘situation’ on your hands. So, do this:
1. Apply the front brake, and rock the bike back and forth? Is the headset loose?
2. Lift the front wheel a couple of inches. Does it flop to one side? If not, the headset is too tight.
3. Spin the front wheel and see if it is true. Notice whether the brake drags.
4. Stop the wheel, and see whether it is loose enough that the heaviest part will swing to the bottom. Wiggle the wheel sideways by holding the tire, and see if the bearings are loose.
5. Examine the tires for wear, sidewall bulging, and seating issues.
6. Spin the rear wheel and see it it is true. Notice whether the brake drags.
7. See whether the rear wheel spins freely, and whether the bearings are loose. Very loose bearings may indicate a broken axle. If it’s not a quick release wheel, try spreading the dropouts apart with your thumb. With a broken axle, they’ll flex outward.
8. Squeeze all the spoke crossings on the rear wheel. If a spoke is broken, it will be evident.
9. Spin the chainwheel backward while observing the chain. Are any pins sticking out of links?
10. Move the shifters just enough to see if the derailleur cables are working correctly.
11. Squeeze the brake levers, looking for too much travel, slow or weak return, and other brake problems. Examine bridge wires if equipped for broken strands. Examine the brake cables at the anchor bolts and at the break levers for broken strands.
12. Suggest accessories as appropriate.
As you make discoveries, write them down with the customer watching and available to ask questions. If several adjustments are needed, suggest a tune-up. Quite often, a customer will come in for a single repair, such as a flat tire or a bent wheel, and end up with much more repair work. If the customer is informed and consents up-front, everyone ends up happy.
Or, you can do it the way it is done in many bike shops. When the customer comes in for something like a broken brake cable, the mechanic or salesperson fails to look at anything else on that bike. During the brake cable replacement, the mechanic notices that the wheel is out of true because it has broken spokes. The customer is called, and suddenly a $15 repair becomes $50. The customer is not happy, but agrees to pay the extra. When the customer picks up the bike and takes it for a ride around the block, s/he discovers that the derailleurs are out of adjustment and the chain falls off. This is not a happy customer. Furthermore, this process can turn a bicycle enthusiast into someone who owns a bike but never rides it.
This bicycle examination may sound like a complex operation, but with just a bit of practice, you’ll remember the steps, and become able to do the whole thing within two minutes.
Many bike shops charge $50 or $60, and sometimes even more for a tune-up. Then, they barely make a profit. That’s because the mechanic spends a whole lot of time going back and forth, not quite knowing a good sequence, and even misses noticing some things that need adjustment. I’d like to suggest learning this step-by-step process to speed your tune-up time, and make sure you catch every detail. With a tune-up procedure like this, your shop can charge $30 per bike, making a large profit, and end up with a zillion customers bringing their bikes in for service. Keep in mind, too, that you can sell tires, additional repairs and accessories to almost every tune-up customer.
1. Adjust the headset if it is an adjustable headset. (This is done first, because it is best done before the bike is mounted in the workstand.)
2. Adjust the bottom bracket set if it is adjustable.
3. Adjust the front wheel bearings if adjustable.
4. Adjust the rear wheel bearings if adjustable.
5. Adjust the rear brake, check spoke tensions, and true the rear wheel on the bike.
(I consider adjusting the brake and aligning the wheel a single procedure, since a bent wheel prevents good brake adjustment, and you can use a properly adjusted brake to witness wheel condition. During this process, I typically keep a spoke wrench and an adjustable wrench in my hand.)
6. Adjust the front brake, check spoke tensions, and true the rear wheel on the bike.
7. With the chain engaged on the largest chainring, adjust the rear derailleur.
8. Shift to the smallest front chainring, and check rear derailleur adjustment.
9. With the chain engaged on the largest rear sprocket, adjust the front derailleur.
10. With the chain engaged on the smallest rear sprocket, check the front derailleur adjustment.
11. Check all the nuts and bolts on the entire bike, especially accessories. Make sure to check brake pivot bolts, the bolt that mounts the rear derailleur if equipped, the derailleur tension pulley bolt, the front derailleur cage closing bolt, cotterless crank mounting bolts or nuts, pedals, cable anchor bolts, and handlebar stem.
12. Adjust the air pressures.
13. Test ride the bike. You’ll be amazed at what you can miss, even if you’ve tuned thousands of bikes.
14. Spend just a few minutes cleaning the bike. With a rag, you can quickly attend to the spaces between spokes. With a rag and a bit of furniture polish – or your choice of mild chemical treatment – you can quickly rub down all the major frame tubes. A bit of coarse, dry steel wool can work rapid magic on rusty chrome surfaces.
What an unexpectedly cleaned bike can do for customer satisfaction is remarkable. Cleaning bikes that are in for service is one of the best ways to make your bike shop go viral.
People who perceive that you’ve done something wrong will tell their friends, and that, of course, is bad for business.
People who are merely satisfied with your work won’t tell their friends.
But people who get an unexpected pleasant surprise will tell everyone, and you can end up with much more repair work.
Your author used to go one extra step, and that’s probably why his bike shops grew rapidly and were quite profitable. When a bike came in missing a water bottle, I’d put one in their bottle rack. It didn’t matter if they already had a bottle at home, or didn’t like the color. They loved the thought. Sometimes, I’d add a tire pump, new grips, handlebar tape, reflectors, whatever I thought the customer would appreciate. Sure, this cost a few dollars per bike, but it was cheaper than advertising, and way more effective!
In most of the United States as well as the rest of the world, the owner of a bicycle shop gets a sales tax number, often called a ‘resale certificate.’ This authorizes you to collect sales tax. Now, that’s probably not something that excites you, but the flip side is that you can contact wholesale bicycle suppliers and get inventory and supplies for much less money. Generally, an item that sells for $20 will cost you $10. It’s a sliding scale. An item that sells for a dollar will cost you fifteen cents. An item that sells for $500, will cost you $400.
You may not be in a position to get a resale certificate. You may not have a commercial building, instead working out of your house, or running a mobile bicycle repair business. You might not be in business at all, but wouldn’t mind getting your hands on wholesale prices.
Due to eBay and other online venues, it is becoming easier to convince wholesalers that you are a ‘legitimate’ buyer. Some will require a genuine retail store. Some even have protected dealerships, meaning if someone sells the same brand within a certain distance, you cannot sell the same brand. Others are loosey-goosey. Some only require that you spend $50 or more at a time.
You don’t always need to deal with wholesalers to get good prices. You’ll find many good deals on not only new, but also interesting used and even collectible bicycle parts on eBay.
For general repair work, you’ll find adequate cables, brake pads, inner tubes, tires, and a few other common replacement parts at stores like Walmart and Target. Interestingly, these parts can be as inexpensive as wholesale in small quantities.
For more specialized parts, you might want to visit your local bike shops. If you are running a small repair business, tell them. Most will be supportive, offering a small discount, so they’ll get all your business. To the average bike shop, it is well worthwhile to give ten or twenty percent discounts to regular customers.
The reason pedals, seat pillars, cranks, and nuts and bolts often become stuck in bicycles is corrosion. There is also an effect called ‘electrolytic action’ in which electrons of dissimilar metals trade orbits. So, when you put a steel bolt into an aluminum component, they almost weld together over time.
A tiny layer of lubrication stops electrolytic action and corrosion in their tracks. So, it is recommended when you reassemble cranks, install seat pillars, put on pedals, or assemble nuts and bolts, that you always use a tiny bit of oil or grease. Years later, you’ll be glad you did.
You may find that a bit of grease when assembling brake and derailleur cables makes a world of difference in smoothness, ease of use, and long life.
You’d think after all these years, someone would have invented the perfect chain lube by now. They haven’t. Every oil this author has tried either gathers dirt, or doesn’t lubricate well.
An interesting aside: Years ago, your author read a book on bicycle repair by an American author. He recommended using paraffin wax as a chain lubricant, going so far as to describe how you could melt the wax in a coffee can, then soak the chain in it. Your author considered this absurd, but thought it might be worth a try, just in case it was for real. It quickly became evident the author made the whole thing up. My chain was so stiff with wax that it almost couldn’t be put on the bike. Then, when the bike was ridden a hundred meters, all the wax chipped off, leaving no lubrication at all.
In time, this author figured out what happened with that author. He had read an English book on bicycle repair that suggested cleaning a bicycle chain with paraffin, which in England can mean kerosene. Figuring the original English author had probably said “cleaning” when he meant “lubricating” he went ahead and wrote up a procedure the he never actually tried.
No doubt, I too, have made some errors in this book, although my goal is accuracy. It helps that I have some experience, having repaired or customized more than 15,000 bikes over a 15-year period, while owning and operating three bicycle shops.
Enjoy, experiment carefully, and keep the world’s bikes running! – Jeff