Originally Posted by dooley
Yes it does, the amount of force on a chain running a 25/9 is nearly twice the force on one running 44/16, it's simple leverage.
To that you have to add the fact that there're less teeth to carry the load and you get worn sprockets, ****ed driver bearings and broken chains.
My bad, you're right about the leverage. However, the thing to understand is *still* that BMXers aren't roadies, they're not climbing Alpe D'Huez and the drivetrains don't suffer that much routine wear and tear from *pedaling* forces. They do however get smashed on things and thrashed around quite a bit, the kind of abuse that smaller gears handle better than bigger ones. So far nothing I own on my BMX bikes has actually *survived* long enough to wear out.