We can rebuild him. We have the technology… (The Six-Million-Dollar Man)
The On-the-Road Repairs chapter discussed repairs you may have to make on the road. Now we’ll talk about servicing and repairs in the shop. Again, I will remind you that I won’t try to lead you through the operations step by step—I’ll let YouTube do that. I will just tell you what needs to be done, and tell you the things the videos tend to leave out.
Road bikes are surprisingly simple and easy to work on. The average person with average mechanical skills can learn to do 90% of what it takes to keep a bike in good condition in a day. Working on bikes is also fun, because a bike is one of the few things left in our world that are almost entirely intuitive and apparent—you look at it and say, “Oh, yeah, I see how that works.” Can’t do that with your smart phone. So I encourage you to try your hand at it. Anyway, you don’t want to be running to your LBS every week.
Beyond the usual homeowner’s toolbox of screwdrivers and crescent wrenches, you will need:
1. Access to the internet—so you can watch the how-to video on YouTube.
2. A floor pump (it doesn’t pump up the floor; it stands on the floor). Spend enough money to get quality here. It’s amazing how many floor pumps made by respected companies work poorly. Get one whose valve head (the thing on the end of the hose) latches easily and firmly over the tube’s valve stem by means of a throw lever, pumps without spilling air, and detaches quickly and easily without doing damage to your fingers. Don’t buy a pump where the valve head just pushes straight onto the valve stem and pulls off by force—it wears out soon, and it puts tremendous strain on your stem and will eventually rip the stem out of your tube. Make sure the pressure gauge is mounted at the top of the cylinder, not at the floor end, so you can actually read it. There are companies that specialize in making pumps, Serfas being my favorite. When in doubt, buy the one your shop is using.
3. A set of metric Allen (aka hex) wrenches. These are the crescent wrench and screwdriver of bike maintenance, the tools you use every day. They come in several forms: 1) the multi-tool, which is intended to be carried on the bike but will serve in the garage in a pinch; 2) a set of simple L-shaped wires in different sizes; 3) a Y-shaped wrench with the three most commonly used sizes of hex head on the ends; and 4) a fancy set of T-shaped wrenches with ergonomic handles. The best Allen wrenches have little balls on the end, which make it easier to insert the wrench in the hole. Since you will use these every time you work on your bike, you can justify splurging. If you have Allen wrenches already, they’re probably not metric and won’t work on bikes.
4. A bike stand, to hold the bike firmly and off the ground while you work on it. Don’t go cheap—bike stands have to be heavy to be stable. Make sure the clamp fits your seat post—some quality stands can’t clamp onto some major-brand seat posts, and the seat post is the only place on your bike where a bike stand can clamp without risk of damage.
5. A chain tool. It opens a link in the chain so you can make the chain the right length. You’ll need it every time you replace your chain, and more often if you don’t have a quick-link (see #6).
6. Quick-link pliers. Most modern chains are closed via a quick-link, a handy link that slides open and shut and makes installing or removing a chain easier. It’s impossible to get it open without a proprietary tool. Luckily the tool is cheap ($10).
7. A chain whip. Despite its name, it has nothing to do with the chain—it’s used to tighten the rear cassette or remove it from the rear wheel hub, which you do to replace the cassette or move it from wheel to wheel.
8. A lock ring remover. It works with the chain whip to remove the cassette’s lock ring. Cheap.
9. A pedal wrench, to remove pedals, which you do whenever you replace pedals, lube pedals, move pedals from one bike to another, or rent or demo a bike (at which time you’ll want to use your own pedals). You can make do with other tools with the same span, but they’re all half-measures, so spring for a dedicated pedal wrench right off the bat.
10. A tube patch kit, to fix flats. It comes complete in a little box and is good for about 10 flats. Make sure you’re getting the kind with the tube of glue—don’t get instant patches, which are good for mountain bike tires that run 25 psi but not road tires that run 90 psi. Once the tube is opened, its days are numbered, so don’t open it until you use it—otherwise you’ll be riding around with a dried up tube of glue in your seat bag. You can buy just the glue if you’re out of glue but have patches left.
11. Tire mounting levers (aka tire irons), to take tires off wheels. You’ll need to carry one pair on the bike, and they’re cheap, so consider getting two, one for the bike and one for the garage. Make sure they’re plastic, not metal (metal damages rims and tubes) and they’re wide—tongue depressor width, not popsicle stick width. I actually use 3 irons to remove a stubborn tire.
12. A tape measure—in inches and centimeters, since bikes use both systems
13. A digital tire pressure gauge. It sounds like a geeky indulgence, but it’s important. There’s a gauge on your floor pump, but it’s inaccurate, and tire pressure is something you want to be able to control precisely. It’s cheap ($25).
14. Wet/dry sandpaper, for cleaning rim brake pads if you have rim brakes
15. A torque wrench (nice if you have aluminum parts, essential if you’re working with carbon). “Over-torqued is half broken” says the mechanic’s mantra, especially with carbon, and under-torqued is going to fall off eventually, so you need a torque wrench to tell you when enough’s enough. Torque wrenches can cost hundreds of dollars, but, since almost all carbon components are torqued to 5 Newton-meters, you only need buy a preset 5 Nm wrench that costs about $30 (Ritchey sells one).
16. Oil applicator—some syringe or thin, flexible tube that will allow you to put a drop of oil and no more into a tight spot. I buy little mini-bottles of Tri-Flow, which come with a nifty little applicator tube, throw the Tri-Flow away, and fill the bottle with my bike lube. The applicator is worth the cost of the Tri-Flow.
17. Talc (baby powder), to keep tubes from adhering to tires
18. Grease, for greasing bolt threads. There are dedicated cycling greases, but any quality waterproof grease will do.
Not necessary but nice to have are
19. Cable cutters, to cut off the ends of new shifter and brake cables. Standard wire cutters tend to cause fraying.
20. A chain stretch measurer, a ruler that tells you when your chain needs replacing
21. Torx wrenches, for those rare bolts with the odd star-shaped hole. You have no use for them unless your bike has torx bolts (they’re common on disc brakes), and then you need them.
Film the Disassembly
First, a general caution: if you are going to take anything apart, film the process. However self-evident the disassembly may seem, there will come a moment in the re-assembly when you wonder, “Does that thing go in this way, or that way? Was this on the top or the bottom? Am I putting this in upside down? What’s this thing for?—I don’t remember taking it out.” I take both videos and stills—videos show more but stills are easier to study. And I talk during the videos (“OK, I’m unscrewing this bolt and I see it has a little washer on it…”), so I can remember what I’m seeing and thinking. Do this even if you have a wonderful instructional video to follow, because your bike isn’t theirs and there is always much the video will take for granted.
We will now work our way through every maintenance or repair task you are likely to ever do or have done to a bike, roughly from most important/frequent to least important/most exotic.
Washing Your Bike
You never need to wash your bike. If you’re keeping the lube-able parts lubed and cleaning your chain, the dirt isn’t going to hurt the bike in any way. But washing is a fundamental way of bonding with your machine, declaring your love for it, and lifting your spirits when you ride.
There are four ways to damage your bike during the washing process:
1) If you direct a forceful stream of water onto the bottom bracket or wheel hubs, you will drive water and dirt into sensitive bearings. Just let the water fall gently onto the bike, like rain. Incredibly, there are companies that make pressure washers for bikes—what, they’re trying to get you to ruin your bearings? Retro me Sathanus!
2) Aggressive hosing of wheels can drive water into the rim, so be sparing with the water around your wheels. This is especially true of deep-dish wheels, where the spokes run through holes in a cowling before they reach the rim.
3) Water can find its way inside your frame and collect around your bottom bracket—in fact, some frames fill with water so easily that a good washing will leave a pint of water in there, where it will sit forever unless you let it out. So drain the bike by removing the seat post and turning the bike upside down after every wash. Some people recommend drilling a small hole in the bottom of your bottom bracket (yes, drilling a hole in your frame) to allow drainage. I’ll leave you to decide if you want to do that. Turn the bike upright and wait a few hours (preferably overnight) before reinstalling your seat post, so the inside of the frame has time to dry. Mark your seat post position with tape before removing it. If you go through this process a few times and water never drains out, you know your frame isn’t a water collector and you can skip this step.
4) Washing washes off the lubricant on your drivetrain, so you have to re-lube the chain and derailleurs. If you aren’t willing to do this, I’d skip the washing entirely.
There are post-wash bike polishing sprays and wipes, the equivalent of waxing your car after a carwash. They work, but I never saw the need. Of course I also don’t wax my car.
Servicing Tires and Tubes
Inflation: This is the only maintenance task you have to do every day, or at least every other day. All road tires and tubes bleed air directly through the rubber, so you’ll need to top up, ideally before every ride. After a while you’ll know how fast your tires bleed and thus how often you need to re-inflate.
There are three things worth knowing about pumps:
1. When you remove the pump head from the tube valve stem after inflation, there is a whoosh of air. If you do this cleanly, you aren’t losing tire pressure. The whoosh is air leaving the pump, not the tube. So don’t over-inflate the tube to compensate for the mythical “lost air.”
2. If you check a tire’s pressure by hooking up the pump, the tire will have to fill the pump with air before the pump’s gauge can read, so you’re deflating the tire by that amount, and the gauge will read whatever was in the tire minus what it took to fill the pump—usually about 10 lbs. worth. So, if you’re going for a ride and you want to see if you need air, you can’t check tire pressure with a pump—you need a tire pressure gauge (preferably digital). A pressure gauge takes so little air to fill that it effectively tells you the original tire pressure.
3. Tire pumps have notoriously inaccurate pressure gauges, so if you care about tire pressure (and you should), you’ll need a tire pressure gauge, preferably digital.
Fixing Flats: In addition to what we said in the previous chapter:
Baby-powder the tube and inside of the tire before installing them. Tubes tend to stick to tires when inflated, which prevents the tube from moving and robs you of road comfort. To prevent this, put your tube in a ziplock bag with some talcum powder and shake. Hang the tire around your neck, pour a wad of baby powder into the bottom of the tire, and rotate the tire, letting the powder slosh around the inside as the tire turns. You can baby-powder the spare tube you carry in your seat pack too—be sure to store it in a ziplock bag.
The hardest part of fixing a flat is getting the last 6 inches of tire back on the rim. There are lubricants, like Uncle Dick’s Bead Slip, which help. There are various high-tech levers and pry bars, which as far as I can tell don’t.
When does a tire need replacing?: Road tires don’t have tread like car tires—you can’t just replace them when they go bald since they’re bald when they’re new. Instead, replace them when they develop a flat spot. A tire is rounded at the tire patch when new. When you’re riding, look at the tire patch—if it looks flat (squared off), it’s time for a new tire. Don’t run tires until the rubber is gone—the tire’s performance has gone south long before then.
Rear tires wear out faster than front tires, because they’re running under more weight, and some riders rotate their tires so the two wear out at the same time, but you won’t get more miles out of them if you do. If you doubt this, email me and I’ll explain it.
Tubes: Tubes require no maintenance beyond patching flats. You can patch a tube as many times as you want—some riders take pride in patching a tube 18-20 times—but most patches leak a bit of air, and after a while it’s worth the money to get a tube that holds air.
Tubeless tires that run some kind of slime inside will have to replace the slime every 6 months or so, because it dries out and turns to rubber.
Lubing the Drivetrain
Other than inflating tires every other day, there is only one maintenance task you really must do on a bike: lube the chain. The more often you do it, the longer the chain will last. Chains are supposedly good for about 2000-3000 miles, but if you ride on a dirty chain you’ll reduce that by about 75%. Feel free to lube your chain after every ride if you want to, but be sure to lube it every 20 rides or so. Lube it every time you ride in dirt. Lube it every time shifts start sounding loud or clunky. Lube it every time you ride in the rain.
“Lubing” means “cleaning and lubing.” Dumping chain lube on top of your dirty chain links will do you little good. You can clean the chain with a bike-specific degreaser (and they work well), but most chain lubes have cleaning agents in them, so all you have to do is apply the lube liberally, brush the dirt out, and wipe off the excess. There are nifty little machines with scrubbing wheels that you fit around your chain, and they work well, but they turn lubing the chain into a production and may discourage you from doing it frequently.
Bike chain oil comes in thicknesses. The thinner it is, the easier the bike is to pedal, the less protection you get from weather, and the more often you’ll need to lube. Many oil makers make a series of oils from thinnest to thickest, to make it easy to choose the thickness that suits your interests. There are websites that test chain oils and will tell you which ones roll most easily. According to these sites, the most friction-free “lubes” are in fact waxes, but waxes are difficult to apply and few non-racers bother with them. In a pinch, any not-too-heavy household oil, like Tri-Flow, will do the job and is a lot better than nothing. Riders often switch to a heavier oil in winter weather. Do not use WD-40, ever, anywhere, as a lubricant. Despite its reputation, it’s not a lubricant—it’s a “water displacer” (hence the WD), and that’s all it does well.
When you lube the chain, lube the derailleurs as well. They need it less than the chain does, because they move less often, less distance, and more slowly, but you’ve got the lube out so why not? Each derailleur has eight pivot points—make sure you’re reaching all of them. This is where you’ll need that Tri-Flow applicator tube I told you to buy.
Servicing Chainrings and Cassettes
The only short-term servicing your cogs need is cleaning. When you clean the chain, also clean the cogs the chain runs on: the chainring, the cassette, and the jockey wheels. If you don’t clean them all, the guck sitting on them will be redistributed throughout your nice clean chain. You can clean the cassette by spraying it with degreaser, brushing it, and hosing it off while it’s on the bike (make sure you don’t spray degreaser into the innards), but a thorough cleaning means removing the rear wheel and flossing the cassette—running the edge of a rag or a piece of fat string back and forth between each pair of cogs as the cog freewheels. This is a moderately big deal and I usually do it only when the rear wheel has to come out of the bike for some other reason, like a flat tire.
Long-term servicing of your cogs means replacing them when they wear out. When new, the concavities between the teeth of a cog are perfect semi-circles, but the chain pulls on those semi-circles and eventually scoops them out on the drive side. This happens however often you clean or replace your chain. It’s quite visible. When you see it, replace the cog. The wear is proportional to how much you use the gear, so the gears you use a lot (like my granny) may wear out years before the gears you rarely use (like my 11). Since most cassettes and all chainrings come in sections, you can usually replace only the cogs that are worn. Even if you ride a lot, this is an infrequent repair. I think I’ve done it twice in twenty years.
A thorough mechanic will check the bolts on the chainring spider for tightness once a year.
Replacing a Chain
Bike chains wear out. They are the only part of a bike other than tires that has to be replaced frequently. Long before a chain breaks (actually, pulls apart) it will stretch—the pin holes will wear and become ovals, which allows the links to be further apart. The lengthened chain will wear out your cogs, and you’ll have to replace your chain ring and cassette as well as your chain—an expensive proposition. You will receive no warning that this is happening until it becomes impossible to shift cleanly, and by then the damage is done, so do one of the following things:
- Buy a chain measuring gauge and replace your chain when it shows wear
- Replace your chain every 2000-4000 miles, depending on how often you clean your chain
- Replace your chain every year (if you ride regularly) or twice a year (if you ride a lot).
Servicing the Rear Derailleur
If you have electronic shifting, it’s pretty much a black box—you can’t work on it or repair it. Adjust it by consulting the manual.
If you have cables, the only frequent service is adjusting the rear derailleur when the shifting becomes imperfect, maybe every couple of months. We talked about how in the on-the-road chapter, but there are subtleties and especially here videos are helpful. Remember, there are only two likely possibilities, the cable is too tight or it’s too loose, and since cables don’t shrink it’s almost always that it’s too loose.
Beyond cable tension, derailleurs don’t need maintenance other than lubing when you lube the chain and the occasional wash if you’re of a mind to. Once in a blue moon, if the derailleur is reluctant to make upward shifts, you have to replace the spring.
You can prolong the life of your derailleur springs by leaving the chain on the smaller cogs (front and rear) when you’re off the bike. The larger the cogs, the longer the path the chain has to travel, and the more the derailleur springs are stretched. Shift to smaller cogs and the springs will be more at rest as the bike sits in the garage.
Some compulsive mechanics dismantle, clean, and regrease their jockey wheel bearings, but that’s pretty nuts. Those bearings are intended to be used until worn (which seems to be never), then replaced.
Servicing Skewers and Thru-Axles
With skewers, almost no one ever does it, but it’s a good idea to lube the cams. It doesn’t enhance performance, but it makes it much easier to open and close the skewer, which is something you do on the front wheel a lot. It will also silence one of cycling’s most annoying and elusive creaks.
If you take a skewer apart, when you put it back together it’s easy to get the coil springs in backwards. The fat end of the coil goes outward. If you install them reversed, the skewer will work but it will be hard to get the wheel into the dropouts.
Thru-axles need as much servicing as any other bolt: none. If you’re a perfectionist, grease the threads now and then.
Servicing Pedals and Cleats
Why would you ever need to remove your pedals? Surprisingly, pretty often: when they need to be replaced, obviously (once every 10 years), but also when you have more than one bike and you don’t want to buy pedals for each, when you want to ride someone else’s bike, when you demo a bike, when you go on a trip and plan to rent a bike when you get there, when you have a noise and want to find out if it’s your pedal…. So more often than you’d think. If these needs never come up, remove and reinstall your pedals once a year anyway, because they can get frozen to the crankarm. Every time you remove your pedals, grease the spindle threads—smear them with any high-quality waterproof grease until the threads are full, then wipe off any excess with your finger.
Pedals don’t have to be super-tight, because they’re designed to self-tighten with every pedal stroke (which is why one is reverse-threaded. And who figured that out? The Wright Brothers, of also invented heavier-than-air flight). Firm will do. But many LBS’s don’t know this, so a new bike or a bike just back from the shop may have pedals that have been torqued down so hard you can’t get them loose. So it’s a good idea to remove those pedals when you get it back from the shop, to prove you can. If you can’t, go back to the bike shop and ask that they be loosened.
This is perhaps the only moment in bike maintenance when you’re at real risk of injury. When a tight pedal lets go, the wrench lets go as well, and the hand on the wrench smashes into whatever’s in its path, hard, if you aren’t careful. This is especially true of the pedal on the drive side, since your hand is smashing into derailleurs and chain ring teeth.
Pedals and cleats do wear out over a few years’ time, but there is no obvious sign that this is happening. The bearings in the pedals go, and you can feel this (a gritty sensation) if you rotate the pedal by hand. The cleating mechanism (which can be either in the pedal or the cleat) wears out, which manifests itself in you having a harder and harder time cleating out, increased “slop” in the float, or anything else that feels wrong. Most pedals and cleats can’t be serviced—you just use them until they deteriorate enough to bug you, then replace them. Speedplay pedals can. For this reason Speedplay pedals last a long time. Don’t judge your pedal’s bearings by how well the pedal free-wheels (spins)—spinning is actually a bad sign, because it means there’s little grease in there.
There are two schools of thought on lubricating the cleat mechanism, the parts that actually move when you cleat in or out. One says, lube it with something light that doesn’t attract dirt. The other says, never lube it, because it only attracts dirt. Pedals will work without lubing, but getting in and out of them gets easier with lube. On the other hand, if the lube attracts dirt they work worse than if you hadn’t lubed them. So it’s up to you.
With some shoes, you walk around on the heads of the bolts that hold the cleats on and wear those heads down. Eyeball them regularly and replace them before you wear off the head slot, at which point it can become a bugger to remove the bolt.
A cautious rider would torque their cleat bolts once a year to make sure they haven’t worked loose.
Some riders clean their cables—they remove them from the bike, take them out of the cable housing (the tube external cables usually run through), clean both cable and housing, and reassemble the bike. Some also lubricate their cables with a light oil. All of this seems excessive unless it’s fun. Cables are cheap. Just replace them, every year or two. If you want to save money, you can use the brake cables for years, because they do 5% of the work shifter cables do. If you’re broke, replace just the rear shifter cable, since it works ten times for every time the front shifter cable works. When you replace the cables, replace the housings if you have them.
There are two kinds of cable, external (running along the outside of your frame) and internal (running inside your frame’s tubing). External cables are easy to replace; internal cables aren’t. I would let the LBS deal with internal cables, but that’s me.
If your derailleur suddenly starts acting randomly, check to see if you’ve got a fraying cable. If you have a fraying cable and ignore it, soon it will come apart. A cable usually comes apart at one end or the other, and if it’s the end inside the shifter it can be tricky to replace—study the other cable to see how it’s routed.
Replacing Bar Tape
If you’re going to do one bike maintenance task beyond lubrication and fixing flats, make it replacing bar tape. It’s easy, and it’s fun, a kind of craft project. Bar tape can last for years, but don’t let it—it goes flat, like the padding in bike shorts and gloves, it gets dirty, and you get bored with the color. For $20 you can have some fun and rejuvenate your riding.
Rim brakes: Rim brakes rarely get out of adjustment by themselves, but if you change wheels and the new wheels have a different rim width, or you install new pads, you’ll have to adjust the pads accordingly. Look at three adjustments:
- Distance from the rim. You need to be close enough that the pads grip when you apply the brakes, but far enough way that the wheel can revolve without rubbing.
- Height. If the pads ride too high on the brake track, they will rub on the tire when you apply the brakes and cut through your sidewall.
- Noise. Some pads emit an ear-piercing shriek. To silence this, toe in the pads.
Brake pads tend to glass over, so they work better if they’re scrubbed with wet/dry sandpaper occasionally to rough them up. Whenever you do this, clean your wheels’ brake tracks as well. Scrub the tracks lightly with a cleaner and a non-abrasive cleaning pad like the Mr. Clean Magic Eraser.
Pads like to pick up metal shavings from alloy wheels and sometimes road debris. You’ll know it when you hear a grinding noise. Dig out what’s causing the noise, soon, before it ruins your brake track.
Pads last a long time, but eventually you will have to replace them. There are grooves in the braking surface, put there by the manufacturers for just this purpose—replace the pads when the grooves are gone.
Disc brakes: discs are complicated, and you have my permission to have them serviced by your LBS. They commonly need three kinds of attention:
- If you hear a quiet intermittent rubbing, the rotor is touching the pads as it revolves, and you need to realign the rotor by removing and reinstalling the wheel or shove the brake pad back from the rotor. This is a routine problem you need to get good at solving.
- Brake pads wear out fairly quickly on discs (which is why they work so much better than rim brakes), so keep an eye on wear and replace the pads before you need to. Otherwise you’ll be braking by pressing metal to metal, which will ruin the brake.
- If you lose braking power, you probably have air in the hydraulic line and you will need to bleed the system. This can be simple and it can be complicated, depending on your brake design—check your manufacturer’s service videos to find out which.
Servicing Seat Posts
Surprisingly, alloy seat posts, which never move, need servicing. They can literally weld themselves to your bike frame. To prevent this, remove the post and regrease the section that goes inside the seat tube once a year.
If you have a carbon seat post, you don’t face this problem, but it’s still a good idea to remove and re-install it once a year. Don’t lubricate the end that goes in the seat tube—carbon is slick, so you may need to go the other way and prevent slippage by smearing the post with carbon-grip compound, which is intentionally gritty.
If you’re washing your bike at all, this post removal will take care of itself when you drain your bike.
Saddles don’t need servicing—just replace them when they get flexy or break. You can extend the life of your saddle by taping its “hips” (the widest points width-wise) with scuff-resistant tape. Saddles don’t experience a lot of wear, except on those two spots, which get scuffed every time you lay the bike down on its side.
Saddles tend to work their way backwards along the saddle rails, so once you find a good fore-and-aft position, it’s a good idea to mark the position of your saddle clamp by wrapping a small piece of tape around the rail where it exits from the clamp.
Most riders never service their shifters at all, and just replace them when they fail. There’s nothing wrong with that—shifters should last several years without attention. If you want to maintain them, it’s easy and videos will show you how: remove the hood, remove a cover plate to expose the mechanism, degrease and re-oil the mechanism, grease the ratchets, reassemble. Yes, dirt accumulates in there, but servicing doesn’t seem to make much difference, so suit yourself. I would suggest going through the cleaning regimen if the shifters are acting up, before you go to the expense of replacing them.
Trueing your wheels
Wheels are “true” when they’re in a perfect plane. When they’re “out of true,” there are very slight bulges or wobbles in the rim. If you have rim brakes, you can do an informal trueness check by spinning the wheel and watching to see if the distance between the rim and the brake pad is constant. But wheels can be out of true so slightly that the eye can’t pick it up this way, and it’s still worth fixing. Ask your LBS to check to see if your wheels are true once a year. You can try to fix it yourself, but truing a wheel is the most subtle of the mechanic’s arts and novices usually make the problem worse.
Servicing the Headset
Take your headset apart and clean and grease it once a year, more often if you ride in dirty or wet conditions. It’s easy and requires no tools other than hex wrenches.
Frequently check your headset for tightness. If your headset is too tight, the handlebar will resist turning. If it’s too loose, the steering will become uncertain and eventually the headset will fall apart. The rule of thumb is, tighten the headset cap until it’s too tight (the handlebar begins to resist turning), then loosen it just enough to lose the resistance.
Servicing Wheel Hubs
Check for two issues, looseness and wear.
Looseness: Hubs can work loose and develop play. To check, stand beside the bike, hold it firmly, and try to wiggle each tire back and forth sideways. There should be no or next-to-no wiggle in the hub. If there’s excess play, remove it. You can do it yourself—it only takes two cone wrenches (cheap) and a video. Depending on the wheel, you may have to do this every week and you may have to do it never.
Wear: To check for worn bearings, take the wheel out of the frame, hold the wheel by the dust seal (the first thing the skewer goes through) with your fingertips, and spin the wheel. Feel for any grinding, resistance, or unevenness at all. There should be none. If you feel anything, take the wheel to your LBS for a consultation and possible bearing replacement. Modern bearings are sealed and can’t be serviced—they’re just replaced.
Servicing Bottom Brackets
I suggest you have your BB taken apart and cleaned once a year, because a) the BB is a crucial factor in how well your bike pedals, b) it’s down there close to the road, where the dirt is, c) it’s where water that gets into your frame collects, and d) BB problems are rarely obvious. Servicing a BB takes some proprietary tools, so most riders have their shop do it for them. As with most servicing, it makes sense to do it in the spring, when the bad weather is past. You can do a rudimentary BB check by putting the bike in a stand, removing the chain from the chainring, and rotating the crankarm, listening and feeling for anything—noise, hesitation, roughness, grinding, sideways play. Anything other than perfectly smooth, firm silence needs attention.
If you hear a creaking or clicking when you pedal, especially under a hard effort (as in steep climbing), and the noise doesn’t come from an obvious place, suspect the bottom bracket.
Stems don’t wear, so just check the bolts for tightness once a year.
Almost no one does this, but it’s officially a Good Thing to go over the bike every six months, put a wrench on every bolt you can see, and make sure nothing has come loose. Do this when you’re chasing a mysterious noise and every other test has failed.
Once-a-Year Check List
To save you from having to do it yourself, let me bring together all the things I’ve just said you should do once a year in the way of maintenance:
Remove and reinstall your seatpost
Have your bottom bracket serviced
Check your tires for wear and replace if the wear is noticeable
Consider replacing your cables, or at least your rear derailleur cable
Examine the teeth of your front and rear cogs for wear and replace if the wear is noticeable
Replace your chain or measure it for stretch
Remove, regrease, and reinstall your pedals
Check your disc brake pads for wear and replace if they’re well-worn
Sand your rim brake pads wit wet/dry sandpaper to improve grip
Clean your rim brake tracks to improve brake pad grip
Replace handlebar tape (if you care about aesthetics)
Service your headset
Check wheels for truth (rim wobble)
Check wheel bearings for any slop or roughness or grinding
Check bearings in pedals and jockey wheels for roughness or grinding
Re-torque all bolts (or just make sure they’re tight)
This list doesn’t include servicing you should do more often than once a year, like cleaning and lubing your drivetrain.