Monday, April 2, 2012

asking Nick

I wrote a letter to Nick this morning.  I really hope he responds...

Actually, what I really hope for (beyond world peace) is a bottom bracket "standard" that is light, stiff, easy to understand and maintain and, most of all, is actually standard!

Hi Nick,

I need a comprehensive guide on BB30 maintenance. 

I think we’re all very familiar with the chronic creak potential of BB30, yet it seems to me there’s no reliable way of assuring that (1) a newly installed crank won’t develop a creak and (2) the spacers and dust covers have been installed properly such that the crank spins as freely as it should and that, to the extent that one can expect, the bearings are protected from contaminates.

My best success in installing BB30 cranks comes when I install a new bottom bracket using a headset press, then install the crank.  As far as what to do about spacers and dust covers, it all seems like so much guess work, so, I guess, and usually (I think) things have worked out ok.  However, the real trouble comes when a crank has to be pulled (for, say, sending a Quarq to be serviced, or simply moving the crank to another bike) and those pesky bottom bracket cups stay with the crank spindle rather than in the frame.  Of course, getting a BB30 crank out of the frame is a taxing and stressful experience in and of itself, but beyond that, in my experience, there’s no “good” way to remove a BB30 bottom bracket bearing race from a crank spindle without _feeling_ like the integrity of the bearings have been compromised.  (I recently saw a tool made for this purpose with a Specialized stamp on it, though I haven’t been able to experiment with it yet.)  So when I have to pull a crank and reinstall it, I leave the bearing race on the crank, but it seems that when I do that a creak _always_ develops after a few hours of riding, even when using Loctite to secure the bearing race, as per the recommendations of Specialized and Park Tool.

I’m coming to the conclusion that I should consider BB30 bottom brackets as one-and-done installations.  In other words, if it crank has to be pulled for any reason, I might as well discard the bottom bracket.  This frustrates me on several levels, and I really don’t want it to be true. 

On the second point, regarding when and how to use spacers and dust covers, I’ve found the documentation that accompanies a SRAM BB30 bottom bracket to be completely unintelligible.  Sometimes I finish an installation and notice a bit of spindle (maybe 1 mm) hanging out of the frame’s bottom bracket shell in a most disconcerting manner.  But, if there’s no creak, I’m super hesitant to pull the crank and experiment with possible solutions because (1) it’s damn hard, (2) the aforementioned concerns about bearing integrity, and (3) if the thing’s not creaking, I don’t want to change anything! 

So, your thoughts?  Secrets?  Basic (and not-so-basic) dos and don’ts of BB30 care and feeding?

If it matters, I’ve been sweating over BB30 bottom brackets for nearly four years with varying levels of success on two different Tarmac SL2 S-Works, a Crux, and a CAAD9 CX, all with Specialized S-Works cranksets.  (I’ve also a Stumpjumper with a press fit BB30, which fortunately has had no creaking issues, but when it comes time to replace the bottom bracket, I’ve no idea how that sucker is coming out.)

Thank you,


If any of the two people that read my blog have any hints, I'd love to hear them.

No comments: