** BB help please **

[velofrog]

i have these beautiful, highly polished white industries cranks, as far as i know they're considered 'compact drive', the ring bcd is 94mm

they're square taper, and i want to fit them to my Pace RC300 frame

i'll probably only be running one chainring

so, my question is, what length axle do i need?

i'm used to more modern bearing cups and old school octalink xtr BBs, this is a first for me!

any help appreciated!

 

[monty dog]

Shiney! Why not ask White Industries or Tim @ Sideways Cycles?

 

[velofrog]

Re:

the cranks came off a 1996 Marin Mount Vision, i just found the specs for that online, and the BB used on that was:

Shimano BB-UN72, 110 mm spindle

so would this work on the RC300?

they both use a 68mm shell and i'm presuming they are both 135mm rear axle spacing.....

so a 110mm BB axle length, even though i'm prob gonna run it 1 x 9......

 

[kyle888]

Re:

Axle length depends on the frame to ensure clearance of the chainstays.

Kyle

 

[hamster]

BB length is generally set by the crank to get the right chainline - chainstay clearance is rarely a problem unless you use extreme size chainrings (like a 52T).

I ran 110 with my WI (Sugino-made). It scraped the 44T outer a little when on the 32T in top. 113 would also work comfortably.

 

[velofrog]

Re:

Cheers Hamster, thought a 113 would be a safer bet, only gonna use a single ring anyway

these are the cranks I want to put your purple rings on btw!

 

[FluffyChicken]

Re:

110 will give same chain line as 113 normally, it just out the nine drive side closer in. You'll have plenty of room.

That is assuming you are using the middle ring for the front ring.

If using the outer ring slot, you may fid shorter crank is better. It's about 7mm difference iirc between the ring slots?
Crank arm only need to be about a mm from the stays. Only these modern wide stance bike seem to have arms far apart.

 

[hamster]

I've PM'd you a link to pictures.

 

[velofrog]

Re:

either the outer or middle, depending on ring size, but no granny ring

 

[stevet1]

Re:

Crank arm only need to be about a mm from the stays.

I've got legs like spaghetti but even I would be able to flex the chainstays enough to cause rubbing with 1mm clearance.