Specialized 2x9 setup?

[verrocchio100]

Hey folks, been sifting thru the forum in attempts to gleen info for the following:

How does one make a 2011 Specialized MTB crankset fit a 68mm shell as listed here:

viewtopic.php?f=1&t=91856&start=15

Thx!

[Colin]

IIRC, you just need a bottom bracket that works with a 30mm spindle.
I believe e.13, rotor, and Zipp all make ones that should work.
http://www.rotorbikeusa.com/products/bs ... acket.html
http://www.amazon.com/gp/aw/d/B0016K1TEO
http://www.wiggle.com/ethirteen-xc-exte ... m-bracket/

[verrocchio100]

Thanks Colin!

I was thinking the same, either Zipp/eThirteen-Hive/WheelsMfg press fit 30 cups (PF30).

But I was wondering about spindle length of the crankset?

Don't know if BB30 cranksets have a longer spindle since they are designed for BB30 frames.

I guess I may have to shim the cups before installing the crankarms but that messes up the Q-factor
and chainline?

Right idea or am I totally off?

[Colin]

Again, IIRC, the Specialized mountain bike cranks aren't true BB30, and actually have a length of close to 90mm (89.5mm?), which is the same, or very close, to a 68mm BSA BB with any of those cups installed. From what I've seen, you shouldn't even need spacers.

[jooo]

This will not work on 73mm BB, only 68m BB. I had to remove all 3 of the 2.5mm spacers, so the cups go against the frame. The only external spacer I used was the wave washer that comes with the cranks on the non drive side - this worked perfect. From my XTR 970 cranks this set up gave me a narrower Q-Factor and 2mm less chain line, whiched I wanted as I'm running 2x9.
My Hive cups are 95 grams. I just saw Clav. has threaded cups for a 68mm BB and 30mm axle that are 72 grams & I'm 95% sure these would work on my set up.Probably try these when I need new BB bearings.

This post from the thread you linked sums it up pretty well.

[thisisatest]

The mountain cranks were originally designed for an 84.5mm bb shell, which they had on some bikes in 2009/2010...
That original layout still had a couple spacers occupying spindle real estate. You basically need 86mm to do it... It's probably doable, but it may be cutting it close.
let us know how it turns out.

[timbat]

I only works with a 68 mm BSA BB.

I used the E13 BB and it worked fine. No spacers and a single wave washer.

As noted the Specialized OSBB MTB cranks are not true BB30 as they are wider.