bb30 with SRAM gxp cranks

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ColnagoJohn
Posts: 66
Joined: Sat Apr 30, 2011 7:50 pm

by ColnagoJohn

I have come to build up my BMC TM01, i have a SRAM gxp bb SRM chainset that i want to use on it.
I have had some BB30 bearings put into the frame and i have a set of wheels manufacturing converter cups. the problem arrises when i put the chainset in. at low torque on the bolt that tightens it all up, (up to 10Nm) the cranks spin reasonably well, however as soon as i go past this up to the recommended 40+Nm the cranks hardly turn at all without a great deal of force put onto the cranks.

Am i doing something wrong? has any body else out there got experience with the bb30 to gxp wheels manufacturing converter cups?

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bikerjulio
Posts: 1900
Joined: Fri Dec 11, 2009 10:38 pm
Location: Welland, Ontario

by bikerjulio

IMO that's an inherently poor solution, which Praxis has addressed and which Wheels appears to acknowledge as well since they are now selling a look-alike. http://wheelsmfg.com/products/bottom-brackets/bb30-outboard.html
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
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kevhogaz
Posts: 232
Joined: Fri Aug 05, 2011 5:18 am
Location: Arizona

by kevhogaz

I used the Wheels unit on my Felt, which is equipped with a BB30 bottom bracket. Never could get it to work right. Had the same problems with tightening the thing down, and it wouldn't spin freely. Ended up using a press in adapter, that's threaded for GXP style cranks. Works prefectly.

In hindsight, I wish I would've tried the Praxis unit.

eric
Posts: 2196
Joined: Tue Nov 11, 2003 9:47 pm
Location: Santa Cruz, California, USA
Contact:

by eric

The Praxis type unit works well. I have the same type of adaptor in my BB30 frame with GXP crank- Praxis's GXP model was not yet available at the time.

The Wheels adaptors require spacers to get the preload right. Sounds like you need to remove one.
It should be explained in the instructions.

kevhogaz
Posts: 232
Joined: Fri Aug 05, 2011 5:18 am
Location: Arizona

by kevhogaz

Eric, I tried every possible combination of spacers, and it never did work right. I gave up on it, and just used my press-in adapter, instead. The instructions were very vague, if I remember correctly.

However, I used a Wheels Mfg. Shimano type adapter in my girlfriends BB30 equipped bike, and it functions 100% as it should. Don't know what my disconnect was on the GXP adapter?

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bikerjulio
Posts: 1900
Joined: Fri Dec 11, 2009 10:38 pm
Location: Welland, Ontario

by bikerjulio

You did get a GXP specific adapter, right?

I'm only asking because in my early days of messing with bikes, I once used Shimano bearings on a GXP crankset, not knowing there was a difference. If a Shimano adapter was used you'd be getting the symptoms that you have.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



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