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Bottom Bracket

By donkerr - Posted on 17 May 2016

NB: Originally posted elsewhere on the Global Riders Network and appears via syndication.

I've managed for the 23rd time to order something online that's 80% the right specifications but not 100% I bought a SRAM X0 1*11 crankset but it's for a BB30 bottom bracket. If I get a BB30 bottom bracket will this fit in the standard bottom bracket hole on the bike or are both the inside and outside widths different. I don't yet have a bottom bracket as I'm building a new bike so wondering whether I have to return the crankset or whether I could get a BB30 for the bike. Thanks in advance. Wow I have almost a shop of bike parts 80% correct now.I wish there was just choice A, B, or C.


What frame do you have?

Santa Cruz 5010. Has a thread. Just realised the bb30 should go I just need to find the correct BB. Is that correct ?

It's a bit of a minefield with bottom brackets.

Give the guys at Summit Cycles a call or even better, take your frame to them and they'll fit the correct bb. They're SC dealers so they'll have the part to fit.

No shame when building a bike to let someone who knows what they're doing and has the correct tools to sort out any tricky bits. If you've not sorted your headset yet, get some advice on that too, it can also cause a few headaches if your frame didn't come with one.

When I built my Niner I did the same, for what it cost the guys to press fit mine, it wasn't worth the hassle of me doing the research, buying the tools and risk knackering my frame.

Absolutely agree with getting someone who knows what they're doing with the BB. Last Sunday I attempted a 1x11 conversion, knowing that the bearings in the BB were stuffed. I now have a dismantled bike awaiting a new BB to be shipped - it took forever to remove and it was in a sorry state once removed - fortunately I had the tools, just naively made assumptions that weren't based on reality and should have determined what the BB was and gotten replacement part first.

Good luck.

Just a quick google and the current Santa Cruz 5010 says the BB size is "standard". The fact also you say its threaded then I would say unfortunately BB30 will not fit. In saying this though, that's without seeing the bike. Maybe take a pic or like others say, give a shop a call or take it to them.

I use it on my roadie. BB30 crank in BSA (English threaded BB) frame. Made by Rotor, FSA and one other (name escapes me).

Not sure if its a Rotor cranks thing or more widely usable, but I have a set I've retired that you can try if you're on the northern beaches.

Needs a special wrench which normally comes with the BB when you buy from the Power2Max distributors in Oz.

That's good to know. Does it change the width and hence the chainline?

Thanks for all the help I have worked it out thanks to the team at Summit Cycles. I need a GXP crankset so will do the return. Luckily in one of my other incorrect online purchases I bought a GXP for my Shimano crankset. Pays to keep all this stuff I guess. Although still to find a use for 2 x 2.40 * 24 Schwalbe tyres!

The Rotor cranks may have a wider axle than BB30, and use some spacers to take up the width on a proper BB30 bottom bracket to eliminate end float, with the last few fractions of a millimetre adjusted with the normal preload nut.

Chain line still seems to be close if not the same and I didn't notice any Q Factor change from the Ultegra cranks I had on previously (normally i notice stuff like that) so I think the crank arm shape compensates so the pedals are in the same relative position.

Does that make sense?

The jury is still out on the BSA30 bearing cups. My first set developed a raucous creak after some wet rides and the replacement seems to be starting up this week with a "tick" noise despite no wet rides.

Might have to swallow my distaste and give FSA BSA30 a go.

Time will tell.

Glad you got it all sorted.

How is the bike porn at Summit! Wall to wall filth!!

I'm glad I got 'stuck' with threaded BB80 and Shimano Hollowtech.
4 years maintenance/squeak free. I reckon I could replace the BB in under 100 seconds.

Weak and flexy you say?

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