Barnetts Bicycle Service & Repair Manual

This chapter has several sections. It should be read carefully to prepare for using all the other chapters. The first section is This section covers only the most basic and universal terms. The other chapters will each start with a terminology section with terms that are more specific. The second section is Understanding thread descriptions and thread types is perhaps the most important basic mechanical skill. The third section is Press fits are a means of holding pieces together other than by threading them. It is a system with its own unique set of techniques and rules. The fourth section is Understand- ing the proper use of greases and oils is critical to being a good mechanic. The fourth section is This section covers what types of cleansers, solvents and polishes might be used, and how to use them properly. The last section is This section covers use of common mechanics tools. The other chapters describe how to use bicycle mechanic specific tools. A list of recommended tools is in the appendix. Chapters on individual component areas of the bicycle have more specific terminology and definitions. For the purpose of this manual, the following terms apply to the frame and basic components. Frame: The structural piece, usually a number of tubes joined together, to which all of the components are attached. Fork: The structural piece that attaches the frame to the front wheel. The fork turns to allow the rider to control the bicycle. Frame set: The frame and fork combination. Head tube: The near-vertical tube that is the for- ward most part of the frame. Top tube: The upper tube of the frame that extends back from the head tube to the seat tube. Down tube: The lower tube of the frame that extends from the bottom of the head tube to the bottom of the frame (the bottom-bracket shell). Seat tube: The near-vertical tube that is at the middle of the frame, which the seat post slides into. Bottom-bracket shell: The portion of the frame that contains the crankset bearing parts, which are called the bottom bracket. Seat stay: The two tubes of the frame that start from below the seat and meet the chain stays at the center of the rear wheel. Chain stay: The two tubes of the frame that go from the lower end of the seat tube and meet the seat stays at the center of the rear wheel. Dropout: The fittings at the end of the fork, and at the juncture of the seat stays and the chain stays, to which the wheels are attached. Top tube Seat stay Chain stay Bottom-bracket shell Head tube Down tube Fork Dropout Dropouts Seat tube 1.1 Parts of the frameset. Derailleur: There are two such mechanisms: a front derailleur and a rear derailleur. The front derailleur moves the chain between the selection of gears on the crankset; the rear derailleur moves the chain between the selection of gears on the rear wheel. Chain: The loop of links that connects the front gears to the rear gears. Freewheel: The set of rear gears. Freewheels and freehubs have a confusing overlap of terminology. For clarification, see the terminology section of the chapter regarding these items. In a general sense, the freewheel is the set of gears that the chain turns in order to apply drive forces to the rear wheel.

Crankset: The mechanism that is turned by the riders feet. It consists of two lever arms called crank- arms, one to three gears called chainrings, and a bearing assembly that the crank arms rotate around called the bottom bracket. Bottom bracket: The bearing assembly that allows the crankset to rotate in the bottom-bracket shell. 1.2 Parts of the drivetrain. Wheel: The assembly consisting of the hub, spokes, rim, tire and tube. Hub: The assembly at the center of the wheel that houses the axle bearings, and to which spokes attach. Freehub: A hub and freewheel that have been combined into a single integrated assembly. Spokes: The tensioned wires that join the hub and rim together. Rim: The hoop at the outer edge of the wheel to which the tire is mounted. Tire: The rubber hoop at the outer edge of the wheel assembly. 1.3 Parts of the wheel. Headset: The bearing assembly that connects the fork to the frame and allows the fork to rotate inside the head tube. Pedal: A mechanism that supports the riders foot. It contains a bearing assembly and is mounted to the crank arm. Seat post: The pillar (usually a tube of metal) that attaches the seat to the frame. Saddle: The soft structure that supports the riders posterior. Stem: The piece that connects the handlebars to the fork. Handlebar: The piece that supports the riders hands and is turned to control the bike. Brake lever: The levers that are operated by the riders hands to control the braking function. Shift lever: The levers operated by the riders hands that control the derailleurs. Brake caliper: The mechanisms that squeeze against the rims to control the bikes speed. One of the key challenges to the mechanic is to be able to replace or upgrade parts with compatible parts. One of the most significant obstacles to be over- come is the number of different thread standards used on bicycles. For example rear axles alone come in seven different varieties. Threads are described by a two part number, such as 3/8" × 26tpi or 10mm × 1mm. The first number refers to the diameter of the male ver- sion of the thread and the second number refers to the pitch. When identifying a thread, start with pitch. The first step to identifying a thread is to measure the pitch with a pitch gauge. Pitch is a measurement of the frequency of threads, or the distance from one thread to the next. In an inch system (BSC and Whitworth), pitch is measured by the number of threads that occur in one inch of thread length, and in a metric system pitch is the distance from one thread to the next. Pitch is measured with a pitch gauge by mating the gauge to the thread. If the gauge can be held down in the thread at both ends simultaneously, the thread is identified (see figure 1.4). The best pitch gauges available come with both metric and Whitworth gauges. Although Whitworth is quite rare, Whitworth pitch gauges are compatible with the BSC (British Standard Cycle) threads found on many bicycle parts. Although gauges are not normally marked with the appropriate units, the thread is metric whenever the number in-

mon BSC freewheel threads. Also, Jou Yu (Joy Tech) hub axles have metric diameter combined with inch pitch in some inconsistent cases. When measuring diameter use a caliper. Measure the thread with the axis of the thread perpendicular to the face of the caliper, the axle centered in the caliper jaws and not on any slot in the threads. 0 1 0 1 0 0 0 0 .1 .1 .1 .1 .2 .2 .2 .2 .3 .3 .3 .3 .4 .4 .4 .4 .5 .5 .5 .5 .9 .9 .9 .9 .8 .8 .8 .8 .7 .7 .7 .7 .6 .6 .6 .6 1.5 Correct and incorrect ways to measure thread diameter. cludes a decimal point, and the pitch is in inches whenever the number on the gauge is followed by the let- ter G or the letters TPI (for Threads Per Inch). 1.4 When the teeth of the thread pitch gauge will all go into the threads simultaneously, then the gauge matches the thread. The next step to thread identification is to measure the diameter. Diameter is a measurement of the male threads outside diameter (O.D.). It is usually a nominal measurement. A measurement is a nominal measurement when an actual measurement is rounded up to an even number. For example, a thread with a 6mm diameter is only nominally 6mm. The actual diameter is more like 5.9mm. Metric bicycle threads are available in .5 millime- ter increments, so always round the actual measurement up to the nearest .5mm to arrive at the nominal measurement. Inch bicycle threads are available in minimum 1/16 inch increments, so always round up to the nearest 1/16 inch or its decimal equivalent to arrive at the nominal measurement. Examples: If the thread measures 5.9mm it is 6.0mm. If the thread measures .370" it is .375". If the thread measures 23/64" it is 3/8". Diameter may be measured in inches or millimeters. The best way to determine which units to use is by measuring the pitch first, because the diameter is almost always in the same units (a 1.0mm pitch threaded item is sure to have a metric diameter). The exceptions are on Italian-manufactured frames, which have metric diameter and inch pitch on the fork and in the bottom-bracket shell, and on Italian-made hubs, which may have metric diameter axles with inch pitch. Italian bikes will also have this combination of metric diameter and inch pitch on the freewheel mounting threads, but in this case it is not an issue because the Italian thread happens to be compatible with the com-

1.6 Whether the thread slopes up to the left or up to the right shows the thread direction. Female threads may be identified as left or right by the following test. Install a matching thread pitch gauge into the thread in question with exactly one tooth of the gauge left outside the thread. Rotate the gauge in the threads at least one-half turn clockwise. Observe the amount of gauge teeth outside the thread at this point. If they have increased, it is a left-hand thread. If they have decreased, it is a right-hand thread. If the gauge is rotated counterclockwise instead of clockwise, the results will be opposite. 1.7 Rotate a thread pitch gauge in a female thread to determine the thread direction. It is helpful to know what threads are likely to be encountered in certain situations. The country of origin of a bicycle frame is likely to determine the thread used in the bottom bracket and the fork/headset. Different countries tend to use different thread standards. The standards are BSC (British Standard Cycle), Metric, Italian Whitworth, and ISO. ISO stands for the International Standards Organization. The ISO has adopted many existing thread descriptions to be the ISO standard. Some of these existing threads are metric, and some are BSC. ISO standard threads may have a metric or inch description. Bicycle frames made in Taiwan, and Japan are certain to be BSC or ISO thread. Bicycle frames made in the U.S. are also virtually certain to be BSC or ISO thread, but sometimes small manufacturers of top end racing bikes use Italian threads. Bicycle frames made in Italy are virtually certain to be Italian thread. French bicycles are the greatest source of confusion because they used to be French thread, then switched to Swiss thread, and fi- nally have switched to ISO threading. Bicycle frames from other countries are seen much more rarely, and it is best to rely strictly on measurements in these cases. See the bottom bracket and headset chapters for description of BSC, ISO, French, Swiss, and Italian threads. Female thread diameters are rarely provided. When the pitch is 24tpi, 26tpi, or 1mm the inside diameter will be approximately .7.9mm less than the male. Following is a chart of useful equivalents of thread diameter. Start by taking a measurement in inches or millimeters and then look in the right-most column for the nominal thread diameter. (table 1-1) 7.7mm .303" 5/16" 9.4mm .366" 3/8" 12.5mm .492" 1/2" 14.1mm .555" 9/16" 25.2mm .992" 1" 28.4mm 1.118" 1–1/8" 31.6mm 1.244" 1–1/4" 34.7mm 1.366" 1–3/8" .149" 3.8mm 4.0mm .189" 4.8mm 5.0mm .228" 5.8mm 6.0mm .307" 7.8mm 8.0mm .351" 8.8mm 9.0mm .346" 9.3mm 9.5mm .389" 9.8mm 10.0mm .976" 24.8mm 25.0mm 1.358" 34.5mm 34.7mm 1.370" 34.8mm 35.0mm 1.409" 35.8mm 36.0mm On all pedals and most bottom-bracket threads (as well as other rare occurrences), the final aspect of thread identification is the thread direction. Right-hand threads (most common) tighten or are installed with a clockwise rotation and loosen or are removed with a counterclockwise rotation. Left-hand threads (left pedals, some right-hand-side bottom-bracket parts, and certain freewheel cones and dust caps) tighten or are installed with a counterclockwise rotation and loosen or are removed with a clockwise rotation. Thread direction of male threads may be identified by observation. Held vertically, the threads on a right-hand thread will slope up to the right, and the threads on a left-hand thread will slope up to the left (see figure 1.6).

The country of origin of a component is useful in determining the thread type of fittings within the component, but the threads that attach a component to another component or the frame may be unrelated to the country of origin. For example a bottom bracket made in Japan for an Italian bicycle would be Italian thread. Another example would be that an Italian made freewheel installed as original equipment on an older French bicycle would probably be a French thread. The threads used within any Japanese, Taiwanese, or French component are likely to be metric. The threads used within any Italian component are likely to be metric or Italian Whitworth (a bi- zarre combination of metric diameter and inch pitch). There is little consistency with U.S. component manufacturers to use metric or inch threads. Those U.S. component manufacturers that contract to have their products made in Asia are more likely to use metric threads. For example, Grip Shift uses metric threads on fittings, but fittings on Bullseye hubs use inch pitch threads. The primary form of thread preparation is lubrication. Preparation of threads with oil or grease per- mits ease of assembly and disassembly. Lubrication makes it easier to feel when the threaded component is becoming tight enough. Corrosion is also prevented by lubrication; however, lubrication is counter effective on threads with nylon inserts. In most cases the lubrication choice is between oil and grease. Oil is generally used on threads of small diameter or fine pitch. Ease of application is the primary advantage compared to grease. Grease is used on threads of larger diameter and coarser threads. Its advantage over oil is durability under exposure to moisture and less of a tendency to evaporate. In some cases it is preferable to use a compound called Loctite instead of lubrication. Loctite is a liquid that hard- ens and expands after application. It is not a glue, but works by expanding to fill a gap and exerting pressure between the parts. Loctite used on threads aids ease of assembly, prevents corrosion, prevents threaded components from coming loose and consequentially reduces the need to over-tighten parts, risking their damage. Loctites generally cure in a few hours. The hard cake that Loctite compounds cure into is not an adhesive. The hard cake deteriorates if the threaded item is turned after curing. Use of Loctite is redundant on threads with nylon inserts. (Loctite is toxic minimize contact.) There are several grades of Loctite. Some of the following grades are available from automotive stores or United Bicycle Tool Supply, but some must be purchased at industrial bearing supply companies. Loctite 222 is the lightest grade available and is applicable on thread diameters up to 6mm. Typical uses of Loctite 222 include: accessory mounting bolts/nuts, brake mounting bolts/nuts, and derailleur limit screws. If only one grade of Loctite were to be used, it should be Loctite 242. It is heavier than the 222, and is used on larger diameter threads. Typical uses of Loctite 242 include bottom-bracket fixed cups and headset locknuts, but it is also acceptable to use it on smaller thread diameters. Loctite 290 is a special application thread locker that is more heavy-duty than 242, but can be applied to already assembled components to penetrate into the threads. Typical uses of Loctite 290 include already installed accessories (such as fenders) and already installed bottom-bracket fixed cups. Loctite 272 or 277 are extremely heavy-duty compounds that would not allow removal without damage to the tool or part. They are used when threads are damaged and as an alternative to replacement when permanent installation will not be a problem. Loctite RC680 serves as a substitute for 272/277 and can be used in other non-thread applications on the bike, such as enhancing the security of a pressed- in part like a headset cup. Loctite 660 (Quick Metal) is not applicable to threads at all, but will fill gaps for press fits of up to .5mm. When assembling threads pay close attention to how they feel. Threads that feel tight during assembly should be checked for: Thread compatibility Paint in threads (Clean with tap.) Damaged threads (Clean with tap, die, thread chaser or file.) Cross-threading (Restart thread with better alignment.) That threads feel effortless to assemble is not by it- self an indication of thread compatibility. When the female thread is a larger diameter than the male, no effort will be required for assembly, even when there is a pitch mismatch. If pitch match has not been verified but the difference between the O.D and I.D. of the parts is acceptable, then it is acceptable to use test-mating of parts as a way to determine compatibility. This is a useful tech- nique in cases where it is impractical to check the pitch because of small I.D., or short overall thread length. A thread that gets tight and then feels easier to turn as it is secured is probably stripping.

Ideally, when threads are damaged the part should be replaced. If tools are available and the damage is not too severe, it may be possible to repair the thread. The best repair will be accomplished with a thread cutting tool such as a tap (for internal threads) or die (for external threads). When repairing threads with a tap or die, first make sure the damaged thread and tap or die have compatible thread description. Start the tap or die on the end of the threaded item that is in the best condition to ensure proper alignment. If the die is a variety with a split in it so it can be compressed or expanded, it should be fit in a special die handle that has expansion and compression adjust- ers. Thread the die onto the good portion of the thread with it expanded to a loose fit. Then compress it until it is barely snug before starting to cut on the threads that need repair. An alternative to using a tap or die is to use a thread chaser. A thread chaser does not actually cut threads. It does realign threads that have been mangled. It is most often used on solid axles or the dustcap threads in crank arms. The least expensive way to repair a thread is with a thread file. The thread file is best when there is just a small ding in a thread. Thread files can be used on mangled male threads. Available from various bicycle tool and general tool suppliers, thread files come in both inch and metric pitches. After matching the pitch on the file to the pitch of the thread being repaired, the file is then stroked in the direction of the thread angle, while the item being repaired is slowly rotated. 1.8 To use a thread file, match the file pitch to the thread pitch, then stroke the file at the angle of the thread while rotating the threaded item. Stripped threads can sometimes be repaired just by chasing them with the appropriate tap, die, or thread chaser. If the thread still does not hold after this repair, repair options include use of Loctite 277 or RC680, drilling the damaged thread out to a larger diameter and re-tapping to use a new size, or replacing the damaged part. Using Loctite is a solution only when there is no further need to remove the part. Converting to a larger diameter thread may be limited by available material or parts. Replacing the damaged part has no disadvantage, except cost or limita- tions of availability. To repair a stripped thread by going to the next larger diameter, first drill out the old threads to the appropriate size for the tap that will create the new thread. When drilling to tap, the use of a larger bit than recommended will lead to poor thread depth and will probably result in further thread failure. The use of a smaller bit than recommended will result in the tap jamming and break- ing off in the hole. To determine the correct drill size a simple formula can be used. If it is a metric thread, sub- tract the pitch from the nominal diameter of the thread; for example, converting a stripped 4.5mm × .8mm female thread to 5mm × .8mm requires drilling the hole out to 4.2mm (5.0  .8 = 4.2). Another example: the correct tap drill for tapping a 6mm × 1mm thread would be 5mm (6  1 = 5). For inch thread (which is unlikely to be needed due to the rare use on inch threads on bicycles), a special or unusual drill bit size is needed. Inch size threads require tap drills which are unique sizes that are numbered instead of described by dimension. After drilling out the hole use the appropriate tap for the new thread size. To remove a stubborn nut or bolt first use a penetrating oil and allow to soak for a few minutes. Then use the best-fitting tool possible. If it is a screwdriver, apply heavy, downward force while turning the screw. If a screw or bolt head is deformed in the attempt to remove it, try vise grips locked securely on the head. If vise grips fail, use a small saw (Dremel or rotary tool) to cut a slot in the head to fit a slotted screwdriver. Another alternative is to file flats on the side of the bolt or nut head to fit an open-end wrench. If all of the above fail, the next option is to drill a hole in the bolt or screw between one-half and three-quarters of the bolt diameter and then hammer in a screw extractor to turn out the bolt. The screw extractor is the first option if the screw or bolt head shears off. The last resort is to carefully drill the bolt out with the tap drill that is the appropriate size for the existing thread diameter. The method for determine the correct size for the drill bit is covered in the preceding section, . Then chase the threads out with a tap.

To remove a stripped nut, screw, or bolt that ro- tates without removing first use penetrating oil. If possible, grab nut, screw, or bolt with vise grip to pull up while unthreading. Another alternative is to insert something like a screwdriver underneath the nut or screw or bolt head and apply leverage while unthreading. The last alternative is to use a saw to cut off the nut, screw, or bolt head. A press fit occurs when one part is inserted into another with pressure and is held together by the friction between the mating surfaces. A common press fit is the interference type. With an interference type, the fit is accomplished when a male cylindrical shape is pressed into a smaller hole. The tolerance between the two parts is generally in the range of .1.3mm (.004.012"). Examples of interference press fits include: Headset races pressed into the head tube Headset race pressed onto the fork Dustcaps pressed into hub shells and pedals Bottom-bracket bearing cartridges pressed into a bottom-bracket shell Bearing cups pressed into hub shells and pedals Cartridge bearings pressed into bottom brackets and hubs Cartridge bearings pressed into pedals 30.2mm 30.0mm 30.0mm 30.2mm 1.9 These cross-sections show a properly sized headset race before installation into a head tube, and again after the head tube has de- flected to accommodate the press fit. Another type of press fit is the tapered press fit. In this case the male component is tapered so that the farther it is pressed in, the tighter it becomes. Examples of this fit include: Cotter pins on cotter-type crank arms Cotterless crank arms that fit on a spindle with tapered flats Preparation to install a press fit should include identifying that the male component is a suitable amount larger than the female; cleaning the mating surfaces so that they will be free of lubrication, corrosion, and dirt; and treatment with Loctite 222 if pre- venting corrosion is a concern. To install press-fit components, a special pressing tool is often required (see the section of the book that applies to the particular component in question.) In the absence of a proper tool, sometimes a vise can be used, and if that is not suitable, a hammer may be used. In either case, pay particular attention to the alignment of the parts as they go in. With a hammer, use a block of wood or a plastic hammer to protect the components from damage. With a vise, similar types of protection may also be required. Proper installation of tapered-press fits simply involves pressing the part in hard enough so that it will hold. Preparation to install tapered-press fits includes an examination to determine that the length of engagement is acceptable and cleaning the mating surfaces, so that they will be free of lubricants, corrosion and dirt. For more information and diagrams concerning tapered press fits see the section of this book regarding crank arms. When press fits slip together with little or no effort, Loctite compounds may be used to improve the fit. If the fit requires only mild force to install, it will probably creak or slip under operating conditions, or moisture may penetrate and cause corrosion, then the use of Loctite RC680 would be appropriate in most cases. When installing sealed cartridge bearings (hubs, bottom brackets, and pedals) Loctite 242 is preferred, so that removal will not be too difficult. If a press-fit part slips right in with no effort, but does not jiggle about once installed, then Loctite RC680 is required in all cases except for sealed cartridge bearings. Sealed cartridge bearing installation requires Loctite 242, usually. If Loctite RC680 is used to improve a marginal press fit, the fit should be considered as good as new, except that removal and reinstallation would require re-application of Loctite. If the press-fit part is loose

Not all greases are suitable for bicycle use. Bicycle bearings operate in a relatively low temperature range, so grease designed for automotive use often does not become effective at bicycle operating temperatures. Greases made specifically for bicycle use include Phil Wood, Bullshot, Var, Shimano, Finish Line, Pedros and Campagnolo. The best automotive grease is a light grade of Lubriplate. Grease failure could come at any time. Factory original greases are often of the lowest quality, and also are applied in very limited or erratic quantities. Frames are often inadequately cleaned at the factory, so bottom-bracket and headset grease is often contaminated with abrasives even before the bike has been ridden. For these reasons it is difficult to project the normal time or miles between bearing overhauls. As a soft rule of thumb, 20003000 miles or two to three years of generally fair-weather riding should make a bike ready for an overhaul. The best method to determine whether grease is overdue for replacement is inspection. See table 1-2 below, for causes and evidence of grease failure. The container and applicator of grease is as important as the quality. Open tubs invite contamination; application from open tubs is messy. Grease is best used in squeeze tubes or grease guns. Whether greasing a thread, insertion, or bearing, an ample quantity of grease will reduce likelihood of drying and moisture contamination. Wipe excesses away when assembly is complete. Grease should be treated like any other unnatural substance that can penetrate the skin. Minimize exposure or avoid it entirely by wearing disposable latex painters gloves. Clean hands when exposure is over. and jiggling after installation, it is best to find a better fitting part. If a better fitting part is not available, Loctite RC680 is recommended. Effectiveness may be limited by how loose the parts are initially, and the by fact that with press fitting there is no way to ensure proper alignment of the parts. 30.05mm 30.0mm 30.0mm 30.2mm 1.10 The headset race and headtube here do not have enough di- mensional difference to create enough friction; when Loctite RC680 is added before installation, it expands and creates more pressure (and therefore more friction). Loctite 660 (Quick Metal) is a thick paste that will provide security when the male part is up to 1mm smaller in diameter than the female part. No preci- sion alignment of the parts is assured, but loose pieces that cannot be repaired in any other way may benefit from Quick Metal. A good example would be when the head tube on a Murray or Huffy juvenile bike becomes flared and the headset parts are loose and jiggling. Because these bikes use non-standard oversized headset dimensions, there are no practical alternatives for repair except the use of Loctite 660 (Quick Metal). (table 1-2) Age: This is one of the most likely reasons for grease Lack of grease, grease absent from ball path, to fail, particularly on bikes that see little use. grease caked like half-dry mud. Internal contamination: This other highly likely cause Light-colored greases turned dark, translucent of grease failure is caused by particles worn from the greases turned darker and opaque. bearing surfaces. Moisture contamination: This cause is only likely Reddish rust color in grease, rust on bearing when the bike is ridden extensively in wet conditions. parts, water droplets in grease or bearing area. Colored greases turn a lighter shade. Dirt contamination: This cause of grease failure is Gritty feeling like sand in the grease, not the most likely if contaminated grease that has oozed out same as the rough feeling from a tight bearing. of the bearing is wiped off the wrong way.

Manufacturers of internally-geared hubs recom- mend special oils that are generally unsuitable for use elsewhere on the bike. Sturmey Archer Cycle Oil is one of these, but a suitable replacement would be 10- weight motor oil. One of the cleansers needed for proper bicycle cleaning is an ammonia and water solution for cleaning dirt and removing greasy fingerprints. If using a household cleanser such as 409, Fantastik, or Top Job, they will leave a soapy film that will need rinsing. Window-cleaning compounds clean as well and do not leave a film behind. For cleaning bearings, drive train components and any other heavily greased or oily components, choose between either mineral spirits or non-toxic biodegradable solvents (such as citrus-based solvents.) These are the environmentally correct alternative to gasoline and kerosene. If using mineral spirits, avoid excess contact with skin, eyes, and fumes by wearing rubber gloves, safety goggles, and by working in a well venti- lated area. Mineral spirits and citrus-based solvents leave an oily film and are not suitable as a last preparation before assembling a press fit. Drying time (of mineral spirits or biodegradable solvents) in confined areas such as inside chains, freewheels, derailleur and brake pivots, is quite slow and generally is aided by blowing with compressed air. If using a biodegradable solvent, remember that once it is contaminated with oil or grease it is no longer environmentally friendly. For certain uses, a more heavy duty solvent (such as acetone) is needed. Use acetone or rubbing alcohol when an oil-free surface is required (press fits, braking surfaces). Use acetone on extremely stubborn dry grease. Both acetone and alcohol are highly flammable and volatile, so do not use them around flames or high heat sources (no smoking). Avoid skin and eye exposure, and keep fumes to a minimum by disposing of soaked rags promptly in a fire-safe self-closing metal bucket. Alcohol is far more environmentally friendly than acetone. There are no biodegradable-type solvents that perform the same function as these two compounds. Wax or polish is used to improve the appearance of paint jobs and to protect them. Most automotive waxes are suitable for bicycles. Wax should be applied to clean surfaces with light rubbing. After it dries it should be wiped off with a soft cloth. Check the label of any automotive product before using it on the painted surface of a bicycle. Test products of uncertain suitability on the bottom of the bottom-bracket shell. Oil is used on threads, derailleur pivots, brake pivots, lever pivots, the chain, inside freewheels and inside internally-geared multispeed hubs. Not all oils are equally suitable for bicycle use. The oil needs to be resistant to accumulating grit, durable to exposure to the elements, and light enough to penetrate into tight areas. These characteristics out- weigh the significance of any more technical consid- erations, such as the type of oil base or whether Teflon is part of the formula. Oils that are specifically suitable to bicycle use include: Phil Wood Tenacious Oil Triflow Bullshot Superlube Campagnolo Allsop Finish Line Pedros Lube Wax The oils at the top of this list are generally more suited to use in wet conditions while oils that appear lower down on the list are more suitable for use in dry, dusty conditions. Popular oils that are specifically unsuitable for most bicycle applications include: WD40 Sewing machine or gun oil 3-in-1 oil Motor oil Method of application is very important with oils. Aerosols are environmentally unfriendly and usually lead to excessive application. The only exception to the problem of excessive application is with spray lubricants that are designed to dry in a matter of minutes after application (such as Finish Line and Allsop oils), but these may be the worst offenders environmentally. In general, oils used in external applications should be used sparingly to avoid dripping and dirt accumulation, and excesses should always be wiped off immediately. Overall, the best form of application is from drip applicators. They are economical to use as well, because waste is limited. In addition to their value as lubrication, oils are also used to facilitate disassembling frozen threaded components. Special penetrating oils perform this function best. Triflow, Allsop, and some other bicycle oils are somewhat effective for penetration.

This section covers the proper use of common tools that are not unique to bicycle mechanics. This section also covers the use of the bicycle repair stand. There is a comprehensive list of common tools and bicycle specific tools in the appendix. The types of tools and con- cepts covered in this section are as follows: Box- and open-end wrenches Ratchet drives and sockets Torque and torque wrenches Adjustable wrenches Pliers and vise grips Screwdrivers Utilizing mechanical advantage Hammers Hacksaws Files Grinder Drilling Taps Using repair stands Always use the smallest wrench that will fit. A 16mm cone wrench seems to fit on a hub cone with 15mm flats, but a 15mm wrench is the smallest that will fit. It may be possible to turn a 15mm cone with a 16mm wrench, but it is likely to damage the nut and the wrench. Box- and open-end wrenches are non-adjustable wrenches that are made in specific sizes that are sup- posed to closely match the fittings they will be used on. They come in inch and metric sizes. Metric sizes are most common for bicycles. Certain inch and metric sizes are interchangeable in one direction only (because the substitute is only slightly over-sized). These are: 13mm wrench on 1/2" fitting 14mm wrench on 9/16" fitting 16mm wrench on 5/8" fitting Open-end wrenches contact the fitting at only two points, making them inclined to round off nuts, espe- cially if they are held in poor alignment to the fitting. Their advantage is access from the side of the fitting when access from the end is difficult. They also generally allow a more flush fit against surfaces adjacent to the fitting, so are well suited to low-profile nuts and bolt heads. Box-end wrenches enclose the fitting and contact it at six points, reducing the likelihood of rounding the fitting under heavy load or poor alignment and fit. Their limitation is with low-profile fittings, or fittings with no access from the end. Box-end wrenches come in six-point and twelve-point configurations. The six-point configuration is more durable and has better purchase (surface engagement), but twelve-point wrenches are quicker to get positioned on the fitting. 1.11 Open-end wrench on top, box-end wrench below. Ratchet drives enable working faster because they do not require removal of the wrench on the return stroke. Good applications of a socket and ratchet drive include crank-arm bolts, brake-mounting nuts, axle nuts, and seat-post binder nuts. Socket wrenches (which can be fitted to a ratchet drive, torque wrench, or socket driver, or may come prefixed on certain spanners) are similar in their ad- vantages to box-end wrenches, but even more useful when there is limited or no side access to the fitting, such as with crank-arm-mounting bolts. 1.12 Six-point socket (left) and twelve-point socket (right). Torque is a measurement of a forces tendency to produce torsion and rotation about an axis, used most often in bicycle mechanics to describe the tightness of

Barnetts Bicycle Service & Repair Manual

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