I want to purchase a new FSA SL-K Light Crankset 170mm 52/38T N10 BB30. Only problem is I don’t know if my '11/'12 Cervelo will allow these specs.
I’m now pushing FSA Gossamer 50/34.
Please help 
CK
cervelo uses its own propriety system called BBright. it’s like BB30 in two ways: it uses a 30mm BB spindle, and it has “half” of a 68mm BB shell width (on the drive side). on the other side the frame extends out an extra 11mm. for comparison’s sake, trek’s BB90 frame standard extends out an extra 11mm on both sides. trek: 68mm shell + 11cm on one side + 11mm on the other side = 90mm. get it?
now, SOME cranks are both BB30 and BBright, because they’re built for BBright. you add one 11mm spacer on one side and it works for BBright, you add two 11mm spacers, one on each side, and it works for BB30. so, some BB30 cranks will work for BBright, but it has to be this kind of crank. rotor’s cranks are like this, SRAM’s cranks are like this.
FSA’s website seems to say there are two cranks that are BBright compatible. the SLK Light, and the SLK Light Compact. if you want to make sure you can always go down to that 50x34 if you want to, get the latter.
just make sure that the cervelo you want to buy is a BBright bike. some older models carried forward, like the P2, are not. because the P2, when sold as a complete bike, has a gossamer mega exo crank, that’s definitely NOT BBright. P2 and P3 are not BBright. P5 is. S5 is, R3 is. the newer bikes are BBright. the older bikes are basically the standard that shimano created with octalink II. if you want to know more about these BB standards, we wrote about them.
One thing to add: the bbright standard is actually not proprietary, as Cervelo does not maintain exclusive use of it. They share the specs freely and fully encourage other companies to use the system.
just make sure that the cervelo you want to buy is a BBright bike. some older models carried forward, like the P2, are not. because the P2, when sold as a complete bike, has a gossamer mega exo crank, that’s definitely NOT BBright. P2 and P3 are not BBright. P5 is. S5 is, R3 is. the newer bikes are BBright. the older bikes are basically the standard that shimano created with octalink II. if you want to know more about these BB standards, we wrote about them.
The 2011 P4 has a Rotor crank and isn’t BBRight.
yes, that’s right. instead of proprietary i should have just said that cervelo developed this standard, but did not quarantined it for its own private use. sometimes even if you can patent something it’s not in a company’s strategic interest. bottom bracket standards seem to fall into that category. cannondale either developed, or assisted with and championed (depending on who you talk to) BB30, but it was in that company’s interest to see wide use by other bike brands, so that c’dale would always have a ready supply of BB parts, rather than seeing BB30 turn into a manufacturing cul-de-sac.
BBright’s entre into cervelo’s line comes shortly after damon rinard (who posts here) moved from trek to cervelo. damon developed (if i’m not mistaken) trek’s bb90 standard. but i think damon repented of both the 24mm spindle in favor of 30mm, and he also decided that moving that extra carbon out 45mm from the bike’s centerline, on the drive side, was in retrospect not helpful (because of clearance issues). but he kept the rest of the BB90 idea intact. fatten the spindle, beef the frame up asymmetrically on the non-drive side, and you get BBright. so, before damon: octalink II. anno damoni: BBright.
so, before damon: octalink II. anno damoni: BBright.
Hollowtech not octalink.
BBright’s entre into cervelo’s line comes shortly after damon rinard (who posts here) moved from trek to cervelo. damon developed (if i’m not mistaken) trek’s bb90 standard. but i think damon repented of both the 24mm spindle in favor of 30mm, and he also decided that moving that extra carbon out 45mm from the bike’s centerline, on the drive side, was in retrospect not helpful (because of clearance issues). but he kept the rest of the BB90 idea intact. fatten the spindle, beef the frame up asymmetrically on the non-drive side, and you get BBright. so, before damon: octalink II. anno damoni: BBright.
For what it’s worth, I wasn’t trying to contradict you or anything, just adding to the list of what is/isn’t BBRight in Cervelo’s lineup.
Anno damoni: That’s funny stuff. At first I thought you did a typo.
“Hollowtech not octalink.”
yeah. f*&king up today. hollowtech II, not octalink v2.
Boom! Thanks!
I know FSA’s website only lists a 52/36T (max) combo for the FSA Gossamer crankset but from my knowledge they also make/made a 52/38T combo as well (unless of course they stopped making them). I know a quick ebay search yielded a few 52/38T combos. FSA vision trimax compact also lists a 52/38T combo but someone else will have to chime in about compatibility of vision chain rings on a gossamer crank (I wouldn’t mind that answer myself)… I don’t know off-hand.
Unless of course you want to swap out the entire crankset assembly to something new (ie. shorter crank arms, lighter, etc.)… it might be easier to just swap the chain rings if all you are after is more ‘teeth’… and like slowman already mentioned… you can still switch back to the 50/34T combo if needed.
That’s some good advice!
I really want to change the entire crankset- I have bike parts “ADD” 
That’s some good advice!
I really want to change the entire crankset- I have bike parts “ADD”
Lol… I’ll have to remember that one. Sometimes I wonder if there is really any difference between Triathletes and their bikes vs. women and fashion. If you can’t get a new “outfit” … accessorize, accessorize, accessorize.
Hi Slowman,
I saw this thread last week while we were at the wind tunnel but wasn’t able to reply because I’m always swamped during the weeks we’re there. Love your funny anno damoni reference!
One point of correction, I didn’t develop Trek’s BB90, Doug Cusack had a lot to do with it and others at Trek also contributed.
You and others got the rest of BBright correct. For details, just see the bbright.net link in my sig.
There’s a simple BBright dimensional drawing freely downloadable as a 2-page PDF (right link, “Download drawings”). As Dark Speed Works mentioned, BBright is freely available to anyone.The short slide show describes (and shows in illustrations) the layout of BBright and the justification of each dimensional choice.Any questions, please just let me know!
Mister Rinard,
I’ve just bought a 2007/2008 Cervelo P3 frameset… I’ve read so much about BB30, BBright etc, etc… That I don’t know which BB fits this frame best. I’ve seen a “FSA K-Force Light BB30 10sp double cranck” which I want to buy, but i’m not sure if it fits in the 2007/2008 P3 frame. Can you (or anyone) help me with this?
Greets,
Bas
Hi Bas,
Congrats - your P3 is a very fast bike!
The Cervélo P3 was designed before we invented BBright, so all P3s have standard English threaded (“BSA”) bottom bracket shells. You can install any Shimano crank and bottom bracket, any SRAM GXP crank and bottom bracket, any FSA Mega-EXO crank and bottom bracket, any Campagnolo crank and bottom bracket, etc. as long as it’s English threaded.
Cheers,
Mister Rinard,
Thanx for your fast reaction!
Greets,
Bas
Slowman answers your question in the second post:
just make sure that the cervelo you want to buy is a BBright bike. some older models carried forward, like the P2, are not. because the P2, when sold as a complete bike, has a gossamer mega exo crank, that’s definitely NOT BBright. P2 and P3 are not BBright.
The P3 is NOT BBright or BB30. The 07/08 P3 should of come stock with an FSA crank on it and used a standard english BSA BB. I ran the stock FSA Cranks and FSA BB that came with the bike and then switched to a DA BB. But is is definitely not BB30 or BBright.
edit misspoke and put BCD instead of BSA
A Rotor BSA30 Bottom Bracket should allow a BB30 Crankset to be installed in a 68mm English Threaded Bottom Bracket.
Hi Spencer,
I agree, but that’s just it - “should” work and “does” work might not be the same thing. I’ve not done it, but maybe someone else has…?
(The following will look familiar to you Andrew.)
Just to frame the requirements, there are three compatibilities that need to be met:
BB threading. The BSA30 bottom bracket will fit any English threaded frame for sure.Axle diameter. The S975 axle (30mm) will pass through the cups, bearings and frame for sure.Axle length. The S975’s spacer-adjuster-thingy is easily removed and gives about 11 mm more length on the left. But is it just right, too little or too much?
The first two interfaces are good; the only hesitation I have is the last interface, axle length. I’m not 100% sure that removing the spacer-adjuster-thingy will really give you precisely the right amount of axle. There are three possibilities for axle length here:
If it’s too short it won’t work.If it’s just right it’ll work. Ideally you can fit a wave washer to take up end play.If it’s too long it’ll still work. You can add BB30 spacer(s) to fill up space.
There are a few tricks to adjust the width; glue the Quarq magnet onto the frame instead of using the ring under the BB cup, if the bottom bracket is a touch too wide for the crank axle, for example.
If someone’s actually done it, I’d believe them. But I haven’t, so I can’t confirm 100%…
Cheers,