First, check the chain. Lean the bike on a wall with the chain facing outwards toward you. Push down on the pedal on your side (the right pedal) to put tension on the chain while you measure the length of twelve links. If twelve links measure more than 12 1/8″, you need a new chain (on a new chain, twelve links will measure exactly twelve inches).
The chain should be clean. If you have a non-Shimano chain, you can take it off with a chain tool and soak it in solvent to clean it, then hang it to dry. Shimano chains come off, but you have to break the chain at the right spot and replace the old pin with a special replacement pin. One alternative is to get a mechanical chain cleaner, which is an excellent choice if your chain gets dirty a lot. Once you have your chain off, it might be a nice time to work on the crankset.
First, check each chainring. If any teeth are missing or misshapen, you should replace the chainring with a new one. Remember, replacing a heavy steel chainring with a new aluminum one will save weight. Check that all of the chainring bolts are tight. This might cure some clicking noises you might have been hearing.
If you have serviceable bearings, you can overhaul the bottom bracket yourself. The bottom bracket should be overhauled every year or more often if you ride in wet conditions (Note that sealed bearings will last quite a bit longer). First, remove the dust caps from each of the crankarms. Using the appropriate crankarm extracting tool(s), take off the bolts and crankarms on both sides. Now, loosen the lockring (on the side without the chainrings) with a lockring wrench or other appropriate tool. Next, remove the adjustable cup with a pin spanner while catching the bearings as they fall out. There may be a plastic shell covering the axle and bearings. Pull it out, if you have one. Now you can pull out the axle and catch the bearings from the other side (the fixed cup side). Be sure to count the number of bearings and to note the orientation of the axle and the bearing cages (if you have them). Clean everything out with the solvent of your choice (metal parts only) and check for any unusual wear and tear. If the axle or bearing cups are pitted, they need replacing. Be sure to use new bearings.
Once all of the bottom bracket parts are clean and the worn out parts have been replaced, it’s time to reassemble. Put lots of grease on the bearing cups and put the bearings back into position. The grease should hold them in place. Grease the axle, but not on the ends where the crankarms attach. Put the axle back into place, being sure that the bearings in the fixed cup are seated properly. Next, put the plastic shell, if you have one, back into position. Now, put the adjustable cup on, and try not to get grease on the ends of the axle. Tighten the adjustable cup until it’s snug, then back it off an eighth of a turn. The axle should rotate without catching or grinding the bearings. If there is any play in the axle, tighten it a little more, and check it again. Now, put the lockring back on and tighten it while holding the adjustable cup still with a pin spanner. There shouldn’t be much pressure on the adjustable cup. If there is, loosen the lockring and cup and start again. Once the lockring is back on, check the axle again to make sure it rotates freely with out any play. If it needs adjusting, you will have to loosen the lockring and readjust the cup. Once you are satisfied that the adjustment is correct, put the crankarms back on and tighten the crankarm bolts. Put the chain back on, if you took it off.
Check the pedals. Some of them are serviceable. Check with your bike shop if they don’t spin freely, or pop them open and replace the bearings.
Check the freewheel. If it doesn’t spin easily or is making unusual noises, you might want to take it to a shop to have it looked at. Check the cogs. If they are very worn, or if you replaced the chain, you should probably change the cogs. On Shimano Hyperglide cassettes, you’ll need to use a special tool to take off the cogs. On other freewheels, you can usually use chain whips to unscrew the smallest cog, which will let the whole cassette come off. Be careful to keep the cogs and spacers in order as they might not be uniform, and changing them around could be detrimental to shifting systems. Some bike shops might have individual cogs, but often you’ll have to buy a new cassette, which is a good time to change the gearing to something more appropriate to match your riding style and conditions, if necessary.
Your bicycles drivetrain should be much smoother now, and everything should be spinning freely. I bet you feel faster already!
Samet Yahya Bilir is a freelance writer who writes about vacation and leisure topics such as wreck diving Ireland and Easter Island stones and statues.