Specialized 2x9 setup?

Discuss light weight issues concerning mountain bikes & parts.

Moderator: Moderator Team

Post Reply
verrocchio100
Posts: 6
Joined: Tue Jan 18, 2011 4:25 pm

by 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!

by Weenie


Colin
Posts: 709
Joined: Mon Mar 02, 2009 4:50 am

by 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
Posts: 6
Joined: Tue Jan 18, 2011 4:25 pm

by 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
Posts: 709
Joined: Mon Mar 02, 2009 4:50 am

by 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
Posts: 1510
Joined: Wed Feb 02, 2011 3:48 am

by jooo

xc71 wrote: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
Shop Owner
Posts: 1980
Joined: Sat Jun 13, 2009 4:02 am
Location: NoVA/DC

by 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
Posts: 248
Joined: Mon Dec 26, 2005 12:44 pm
Location: Sydney, Australia

by 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.

by Weenie


Post Reply
  • Similar Topics
    Replies
    Views
    Last post