I’m helping a friend build up a new tri bike from China and am sitting on the fence on a BB30 vs a BSA bottom bracket. I think there’s better compatibility with a threaded style BSA as I think that means I can use GXP or Shimano but the sites I have looked at look sketchy and I read Dan’s article on BB’s but it didn’t really help. Am I missing something?
Define better?
BB30 would offer more options, you can run a 24mm crank (Shimano, GXP) with an adapter.
A BB30 crank will not fit into a threaded Bottom Bracket.
When I say better I mean better selection…it seems everyone is using an adaptor to get away from BB30.
I agree with Matt above. If you get a BB30 frame, you can put a a BSA crankset in it, but not the other way around. Really, there’s not much different technologically, and it really depends on the crankset your friend wants to run.
It depends on how long the bike will be used. For a no-name Chinese frame, which is basically disposable, I would probably go with BB30. For a custom steel frame I intended to keep for years and years I would choose threaded.
Cranks and BBs for threaded will be around for a long time. It was a standard forever. There are lots of classic and vintage frames that people want to keep on the road. BB30 will die out; it has issues, and every year some jackass comes up with a new BB standard. If longevity is not a concern then you might as well make it easy to use the current crop of components, even though the BB30 standard will be phased out, hopefully sooner rather than later.
A BB30 crank will not fit into a threaded Bottom Bracket.
It can be done. I just installed Rotor 3D+ cranks which are BB30 in my P3 with a Rotor BSA30 bottom bracket and it works great.
It only works for Rotor cranks though. The Rotor 3D+ isn’t really a BB30 crank, it’s also compatible with 386 and BBright. The spindle is 22 mm longer than a true BB30 crank which is why there is room for the external bearings. Any SRAM or Specialized BB30 crank will not fit.
Since you sound like you know what you’re talking about I have a hijack question.
I’m going to get a new shiv pro frame set. I want to get a SRAM red quarq. Should I get the GPX or bb30 bottom bracket?
I would get a BB30.
Unless you wanted to move it between multiple bikes, GXP cranks are easier to install/ remove.
I don’t know much about BBs.
Why would I want the bb30 then? Does it work better? Less resistance?
Very helpful.
Why would I want the bb30 then? Does it work better? Less resistance?
From an engineering perspective, BB30 is “better” – They can use lighter weight material for the spindle yet maintain equal or greater stiffness due to its larger diameter and shorter length. The larger diameter bearings will probably also last slightly longer (larger diameter bearings, all else equal, typically have higher load capacity). And because the bearings don’t sit outside the BB shell, the crank can be designed so that the spindle/crank hub is narrower in order to give more ankle clearance when you pedal, which can be a problem for riders with a ‘toes-out’ foot position while pedaling.
So, technically, it’s lighter and/or stiffer, longer-lasting, and better for ankle clearance. Will most people notice the difference? Probably not. And BB30 bottom brackets sometimes have hard-to-pinpoint ‘creaking’ issues, though the newest ‘PF30’ variant from SRAM is supposed to be better in that regard (but these require a slightly different BB shell than a classic BB30 system). While external bearing BB setups for threaded bottom brackets are kind of a kludgey solution to the problem of needing bigger bearings for bigger/stiffer spindles, they work just fine even though they’re not as elegant as an integrated bearing system like BB30.
all the china frames are made with a BSA BB, if the customer wants a BB30 they boar out the threads.
with that in mind i recommend getting a BSA BB
Good post, you highlight the good aspects of BB30 which are significant, but one thing I see missing in this thread is the explanation of the “hard-to-pinpoint ‘creaking’ issues” which are caused most of the time by the cheap Enduro bearings SRAM uses. I have no idea why SRAM does this, these bearings are good for about 50 miles, and then the track the bearings run in, inside the sealed bearing, gets a bit warped, and then the knocking or creaking noise starts. Best thing you can do is after you get your SRAM bottom bracket, replace the bearings with high quality Japanese EZO or, if you have unlimited budget, Koyo bearings and you will have no creaking.
A lot of people complain about the direct Chinese frames, which is exactly what we use mostly at LaMere Cycles, and we did have a lot of creaking and knocking sound issues from both BBs and headsets early on, until we figured out the actual cause of the creaking and knocking sounds, which was not the frame, but the cheap headset bearings the Chinese were sending us with the frames, along with the cheap SRAM crap BB bearings.
If it’s one of those brandless bikes, I’d suggest BSA, which has more tolerance for off-spec manufacturing. BB30, on the other hand, requires more precision.
from an engineering PERFORMANCE perspective, BB30 is better. stiffer, for less weight, with slightly longer bearing life PROVIDED your BB30 is manufactured within the tight tolerances it demands. continual removal and replacement of BB30 bearings is also possible to cause some damage or loosening over time.
I’d be critical of chinese OEM frame makers making high tolerance BB30 within spoec.
PF30 is slightly better than BB30 in this regard. BB30 has it’s strengths and compromises.
if you want something that is most probably going to last longer, with lkess mantainence issues, get the threaded.
Good points. I’d also like to add that BB30/PF30 frame bottom bracket shells are large diameter and have a narrow shell width, so they offer the most flexibility in terms of crank choice, if you’re willing to run adapters.