The magic answer: How to install Red BB30 crank in Venge etc.
Bike: Venge S-Works, OSBB, all-carbon BB shell.
BB: Specialized ceramic supplied with bike
Crankset: Quarq/SRAM 2012 Red BB30 (though this should apply to any Red BB30 regardless of year).
The issue: what do you use for shims, spacers etc between the bearings and crank arms on each side.
What you are supplied with in the crankset box, besides crank, magnets etc: a threaded item that's part spacer, part adjustable "pre-tensioner" that helps space the Non Drive Side (NDS) and an approx. 10mm spacer for DS that is recognizable because it has tiny flanges at each end.
What you are suppled with the frame: metal adaptors for a standard-shaft Shimano crank, the bottom bracket bearings and plastic cups they sit in.
What you need to buy: prob the easiest way out is to buy the entire SRAM/Truvativ Pressfit 30 BB kit, or if you are lucky (which I was) you can get the various washers and spacers from an LBS. They can also be bought from a few online vendors but by the time you've paid about $10 for each of the two sets you need and the freight, might as well get full BB kit from eBay for $30 shipped or thereabouts.
That kit includes two non-descript black washers 2.5mm each; a bunch of really thin clear plastic shims; two black stepped washers (SRAM apparently calls them "dust covers" that also act as covers for the bearings, these have white lettering on them that say SRAM and "30mm spindle and and are prob also about 2mm or 2.5mm thick and are stepped; a wave washer.
What worked: 1) on the DS, the 10mm spacer from the crankset box, one 2.5mm spacer from the SRAM BB kit and one "dust cover".
2) on NDS: the pretensioner that came with the crank; and a "dust cover" from the BB kit.
Dustcovers are fitted against bearings and their stepping allowed them to slip in the hole and fill it flush.
I tried ever other combination, but this seemed to put the chainrings in the sweetspot for the front der.... any less spacing on DS -- leaving off the 2.5mm for example, put small ring right on edge of the low adjustment possible... and maybe past that point. Any MORE spacing on either side (adding the other 2.5mm to NDS, for example) meant that tensioning the crankbolt was able to put so much pressure on the bearings that they wouldnt turn.
Happily, this combination yielded identical crank arm distance from centerline of downtube, which means the crank is centered. It also allows crank install bolt to be properly tensioned.
Note that all available official documentation is of NO help. The crank/BB compatibility chart online at Spesh site mentioned NO spacers. The SRAM installation paperwork that comes with the crank shows a host of different BB possibilities and how to deal with them but isn't clear if one is supposed to be spesh, and clearly the variation shown of PF30 isnt the Specialized verison.
This took about one dozen trial and error crank installations and two trips to my awesome LBS after calls to SRAM and Specialized resulted, basically, in tech guys at both places saying to call the other company.
Spesh tech: "Uh, I think we made that work on one bike, like a year or two ago but I dont know the details. We usually just stick with our cranks. (duh).
SRAM Tech, when told their IKEA-style directions showing five or six options mainly in pictures were of no use.
"Yeah, you should try calling Specialized, they're the ones that made the bottom bracket shell so narrow."
Uh, no (naughty word), sherlock.
Sorry this is so long and probably over-detailed but no one who shells out for a Red BB30 crank and a Specialized OSBB frame should ever have to go through this again, and I wanted it to count for something. Hope it helps someone.
Last edited by thumper8888; 05-16-2012 at 03:59 PM.
I feel ya. I had to go through this also for installing a SRAM S900 on my Tarmac Pro SL4. Had to buy a host of those 2.5mm washers to make it work since my crankset was missing the 10mm DS spacer. Luckily my LBS had those step dustcovers you mentioned. Thanks for sharing.
Is there something different about the S900 crank as compared to the Red crank? You shouldn't need any spacers on the drive side, at all. Just the bearing shield.
Originally Posted by nis240sxt
The Tarmac Pro SL4 has a standard 68mm wide BB. Seems if you get the SRAM BB30 assembly kit things will be ok. I'm actually about to go through this -- installing a 2011 Red crank on a Tarmac Pro SL4. FYI, the Venge BB is different than the Tarmac Pro SL4 BB, Venge uses press in cups (like the s-works Tarmac).
Bottom Bracket - Frame Compatibility
Last edited by mikeyp123; 05-16-2012 at 11:47 PM.
So did some more digging. Yes, I think the S900/975 spindles are indeed longer, hence the need for the 10mm DS spacer.
Also, on the NDS you don't need clear spacers IF you have a pre-tensioner. The clear spacers are to put the correct torque on the bearings. You will have to experiment to find a point where the crank spins smooth at the specified crank assembly torque.
Seems SRAM is pretty bad about documenting how to install the S900/975 cranks, there is absolutely nothing on their website. Their customer service seems rather clueless about the S900/975 crank too. As far as I can tell the Specialized frames are to BB30 spec.
Found this on the Cervelo forum:
SRAM S900 on BBright Installation instructions? -
If you are running a non-S900 crank, you should be good with just the SRAM BB30 assembly kit. I'll be able to verify this in a couple days.
Last edited by mikeyp123; 05-17-2012 at 12:07 AM.
Worked for me
I was having similar problems except I didn't call around to all the different dealers. I was working on installing the Red Quarq on my 2013 S-Works Tarmac. No dust covers from Specialized, no spacers or dust covers from Sram/Quarq (except the 10mm flanged spacer). When I installed the first time, there was still a ton of play, almost 5 mm visually. Did what you suggest with added dust covers and an additional 2.5mm spacer on the DS. Seems to be working now and spinning very smooth.
Thanks for your hard work