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.
Results 1 to 5 of 5
Check out the hottest road bike products from these brands!
See All Interbike Coverage - Click Here »