Truvativ BB and Bulletproof crank problems!
 

Well, I've been riding my recently put together fixie for about six months now and have been dealing with a chainline issue. But the noise finally got to me and I switched the bottom bracket today.

original specs.
Bullet proof crank set with the chainring on the inner spider
According to Sheldon Browns (RIP) site I would have a chainline of 39.7mm with a 107mm BB.
So I used a 108mm truvativ one and the chainline came out real close to the calculated 40.2mm. 40mm by my ruler.

So I went in search of a 112mm BB at the LBS and they gave me a 113mm Truvativ. Well i threw it in and voila. No change in the chainline! That I can tell at least.

But the non drive side seems further out. I'm assuming that this is some mountain bike application and not what I need.

So my questions are.

Should I just try to make a 2mm spacer to put on the drive side cup?

Or should I get a new BB? If so what are you guys using with bulletproofs to get a 42mm chainline?

Thanks a lot.

You didn't, like, put the BB in backwards, did you? They're asymmetrical - the drive side is longer.

+1
there should be an "L" and "R" marked on the bottom bracket to show which side it should face.
It might just be the longer spindle that makes the non-driveside crank arm stick out some, is it causing any problems other than aesthetics?

The drive side cup is made onto the BB itself. i assumed you couldn't put it in backwards. I did put 2mm worth of spacers on the drive side today and it helped a lot.

where did you get those spacers I want a decent chainline with a set of bulletproofs that I am going to get. Also how is the bottom bracket working out after a few months.

i don't think you can put that bb in backwards; it's english threaded, and the drive side cup isn't removable.

Bulletproof+sugino103 with 3/32ring on the outside(45mmCL)+1/8 chain and cog =non noisy drivetrain

wow this thread helped alot. i've just encountered the same problem. i thought when i switched from a 107mm shimano to a 113mm truvativ, my chainline problems had been solved (using bulletproof cranks). however, it looks like the 113mm is truvativ is actually a 108mm truvativ (or a 107mm shimano) with 5mm more on the non-drive side. my chainline is exactly the same as with a 107mm shimano.

guess i'm off to get some spacers myself.