I had a buddy that always complained about his bike’s deraillleur rubbing or not being able to shift correctly. Today I received my free weekly newsletter from RoadBikeRider.com that described his problem: Cross Chaining
What is cross chaining? “Cross chaining is when you have the chain going across the gears stretching it laterally. If you are in the big ring in the front and the big ring in the rear or small ring in the front and small ring in the rear you are cross chaining and thus wearing your drive train much faster than necessary.”
Here’s the Article from “Uncle Al” from www.roadbikerider.com on how to avoid cross chaining.
If you are running double chainrings with that 9-speed cogset, and you are on the big ring, it’s kosher to run up to the # 3 cog (the biggest cog being # 1 and the smallest being # 9).
If you’re on the small ring, it’s cool to run down to # 7, provided you can “trim” the front derailleur to stop the chain from rubbing it, and provided the chain doesn’t tinkle against the big ring.
That’s for normal riding. If you’re racing, all bets are off. In your delirium you can do whatever it takes as long as it doesn’t make you crash.
If you are running triple chainrings, the idea is to run the chain nearly straight to the cassette.
—When on the small inside chainring, use the 3 or 4 largest cogs.
—When on the middle ring, run # 8 up to # 2, occasionally # 1 in a pinch. But if #1 isn’t low enough, you’ll have to shift to the small ring and your chain will drop onto the bottom bracket shell about half the time (unless you have a chain watcher). Prevent this by making your shift to the small ring before you’re up on the largest cog.
—When on the big chainring, it’s okay to run from # 9 up to # 3 regularly, and # 2 occasionally.
The bottom line is that a 27-speed bike is actually a 19-speed but is even better as a 17-speed.
With either chainring setup, never run the small ring/smallest cog combo or the big ring/biggest cog combo, or I will hunt you down and hurt you. You are asking for trouble if you don’t run the chain relatively straight. Those “crossover” combos put the chain at the max angle and cause excessive cog, chain and pulley wear.
The whole purpose of multiple gears is to give you what you need and do it with a good chain line. This results in less wear on your equipment, less noise and maximum efficiency.
There isn’t always the “right gear” for the job. Sometimes, it has to be your legs that make the difference. Don’t be afraid to push a little harder or spin a little faster to prevent cross-chaining. It’ll make you a better and stronger rider.
Obviously you won’t have this issue if you are riding a singlespeed bike