[mutasmurf]

This isn't anything serious, but it is rather annoying. I think I ovalized my bb cup. I'm not 100% sure the thing is ovalized, so someone help me out. My frame is aluminum, and has a BMX sized bb cup. When I was running RaceFace cranks with a mtb bottom-bracket, it would spin freely, no problem (note: I had a mtb-bb-adapter while running the aluminum raceface cranks). Now that I have cromo cranks with BMX bb installed, it doesn't spin as freely. When I'm riding, you can't tell at all, but when I try to spin the cranks backwards, it doesn't spin as much as my RaceFace cranks. Anyways, if it IS ovalized, I guess it's no biggy, as it doesn't really affect anything.

 

[SwisSlesS]

An ovalized bottom bracket would not make the cranks spin less freely. Your bottom bracket is probably just not adjusted properly. I would also say that BMX bottom brackets just spin less freely than mountain bike bottom brackets, especially Race Face, in all cases.

 

[mutasmurf]

Originally posted by SwisSlesS
An ovalized bottom bracket would not make the cranks spin less freely. Your bottom bracket is probably just not adjusted properly. I would also say that BMX bottom brackets just spin less freely than mountain bike bottom brackets, especially Race Face, in all cases.

Nope, the bb is perfectly installed. I and a respected biker, *cough* SamB *cough* (aka 180 kid) made sure of that. Oh well, I'm not gonna lose sleep over this.

 

[Riding 4 Life]

bmx cranks usually don't spin as free as mtb cranks. try taking your wheel off and then spin your cranks, and see what happens. if you've just changed your cranks over and done nothing else. then nothing should be different.

 

[BIG_MAN_290]

are you sure you have the correct spacing between the bearings? because if not, then tightening the crank can put pressure on the bearings and cause the crank to not spin freely.. try loosening off 1 crank bolt a bit and see if it spins more freely..if so, you'll probably just have to ass another spacer between the cups.