Hi all. Does anyone have a recommendation on a bottom bracket for a BB86 frame that will accept a BB30 crankset? I see the Rotor PF4130 as a possible option but can’t find a US dealer to ask about exact compatibility. Thanks all.
Pretty sure that’s not going to work. The BB30 spindle is too fat at 30mm vs 24mm for a standard Dura Ace type crank. Also, the spindle length may be wrong depending on the crank.
I disagree with Kevin, it’s not about the 24 v. 30mm width, as you state the 4130 bottom bracket uses a small enough bearing to make a 30mm spindle work in a bb86 bottom bracket. The problem could be spindle length. A true bb30 crank uses a spindle length that only spans 68mm; a bb86 crank spans about 86mm. Now the confusion that happens is some people call a crank a bb30 crank even if it has a 86mm spindle.
So the question you need to ask is, do you have a 68 or 86mm spindle? If its 86mm then You can make your crank work on bb86, though the bearings on the crank will be small and potentially have a shorter life span.
I just took some bearings off a Plasma TT that does precisely that. But you might have to order directly through Rotor. As I think someone else said, your crank needs to have a 30mm spindle, but can’t be a “BB30” crank. It theoretically needs to be a BBRight or BB386 EVO crankset (Rotor 3D+ Sram - I think all of theirs have a long enough spindle, FSA BB386 EVO). A typical BB30 such as the Cannondale Hollowtech won’t work because the spindle typically is only for a 68mm BB shell.
Anyway, I hope this helps.
It’s not just spindle length for a true BB30 crank as these also have next to no offset. That means that even with a longer spindle, all this would do for a true BB30 crank like the Cannonxale Hollowgram is to push the chainrings ~9-10mm further out from the ideal chainline.
Chainline would be in the exact same place, q-factor would be wider. But it doesn’t matter. No company makes a “BB30” crank with a longer spindle, they’re labeled as something else such as the Rotor 3D+ 30mm spindle and BB30 compatible, but not actually BB30.