Proper Shifting Helps Your Bike Last Longer, Work Better
An important shifting rule is to reduce pressure on the pedals during shifts. Modern drivetrains will shift regardless of pedal pressure. But, if you can always ease up a bit, the shifts will be smoother and your chain, cogs and chainrings will last longer.
Shift Before Hills The hardest place to ease pedaling, of course, is when you're struggling to get up a steep hill. The trick is to shift before the steep part of the hill so you can make the shift with little pressure on the pedals.
Finesse Front Shifts Another thing to remember concerns shifting the front derailleur. You're shifting between chainrings that are significantly different in size. This means that the derailleur has to work hard to move the chain from one to the other. So, the light-pedal-pressure rule really applies here. If you can finesse this shift, you're much more likely to get a clean, smooth shift. And, you'll eliminate problems associated with high-pressure shifts such as having the chain come off.
Shift That Dropped Chain On Speaking of chains falling off, you can usually shift the chain right back on the chainring if it falls off. This isn't possible if it falls off when you're climbing a hill, because you lose your momentum and have to stop. But, anytime you're riding where you can coast for a few seconds, you can almost always get the chain back on by gently pedaling and shifting the front derailleur to move the chain toward the ring.
Pedal slowly and lightly and the ring will grab and engage the chain and you'll be riding again as before. (When a chain comes off repeatedly, something is wrong and you should have us take a look at the front derailleur adjustment.)
Drivetrain Care In addition to proper shifting, cleaning and preventive maintenance can extend the life of your drivetrain as well. For starters, keep your chain clean and well lubricated. Chain-cleaning tools make it a snap to keep your links spotless. We can recommend some.
You should also inspect your chain every six months or so and measure it for stretching. The rule of thumb for checking wear is to put a load on the pedals, pick a chain pin on the top side and measure to any pin 12 inches away. Because the links are exactly one-inch long when brand new, you should be able to measure exactly 12 inches between two pins. If the measurement is 12 1/8 inch, or longer, it's time to replace the chain.
Check The Cogs, Too Keep in mind that cogs wear at about the same rate as the chain. So, if you put on a new chain, your worn cogs won't work right. They'll skip, which is an annoying and possibly dangerous condition where pedal pressure causes the links to ride up and jump over the teeth on the cog. The cure is to replace the cassette cogs.
Remember to keep your front chainrings and rear cogs clean. One trick to removing grit from cogs is to fold a rag in half, place it between the cogs and slide it back and forth. Repeat between each pair of neighboring cogs until the cassette is clean. Don't spray degreaser on the rear cogset because this can penetrate the hub and freehub body, breaking down the grease in those areas, leaving them completely unprotected against friction.