So I know that Rotor has a bottom bracket that will let you use their BB30 cranks with a standard BSA BB, but what about Sram?
I want to buy a BB30 Sram Quarq (for my team bike), but also need it to fit my P3 (BSA). Any suggestions?
(And yes I know I can get a BSA crank and install it on BB30 system, but I kind of want the benefits of BB30 on my road bike)
Sorry but it can’t be done. The Rotor crank isn’t really a “BB30” crank. Its a crank that can be made to fit a BB30 frame. Thats one of the benefits of a BB30 frame, you can fit just about any crank on it with the proper adaptor.
A true BB30 crank has a big spindle and a narrow tread. That makes it tough to fit any other frame as their isn’t much room to fit bearings
no answer, just a (stupid?) question… what are the benefits of a BB30 over BSA?
Crank or frame? For a frame the biggest benefits are more welding area or bonding area for larger tubes and you can fit almost any crank you want.
For cranks, they have a narrow tread and large bearings, so you can have a lot of heal clearance if you like and the bearings last a longtime. Really since square taper cranks and improvements have been relatively minor.
So I know that Rotor has a bottom bracket that will let you use their BB30 cranks with a standard BSA BB, but what about Sram?
I want to buy a BB30 Sram Quarq (for my team bike), but also need it to fit my P3 (BSA). Any suggestions?
(And yes I know I can get a BSA crank and install it on BB30 system, but I kind of want the benefits of BB30 on my road bike)
It can’t be done without modifying the spindle and running ZippVuma threaded cups.
no answer, just a (stupid?) question… what are the benefits of a BB30 over BSA?
The (supposed) benefits of BB30:
Sorry but it can’t be done. The Rotor crank isn’t really a “BB30” crank. Its a crank that can be made to fit a BB30 frame. Thats one of the benefits of a BB30 frame, you can fit just about any crank on it with the proper adaptor.
A true BB30 crank has a big spindle and a narrow tread. That makes it tough to fit any other frame as their isn’t much room to fit bearings
Why won’t it work? You must have the regular Rotor 3D confused with the Rotor 3D+.
I have the Rotor 3D+ cranks (BB30) installed on my P2-SL using the BSA30 bottom bracket. As a starting point, I initially had an FSA gossamer mega exo crank installed.
FSA also makes an adaptor bottom bracket that is equivalent to the Rotor BSA 30 cups. I don’t see any reason why you can’t use another brand of BB30 cranks on either bottom bracket system.
It wont work because the rotor crank isn’t a “true” BB30 crank. It can be put on a BB 30 frame, but so can most cranks. BB 30 cranks are made with a narrow spindle, big diameter spindle. The crank you reference is a wide big diameter spindle. The extra width is where the bearing go on a BSA frame. On a true BB30 frame the bearing go inside the frame and the cranks butt up almost against the bottom bracket shell, leaving no room for the bearings.
i had this exact question in my head about 3 weeks ago - i then had a bike with the Sram 975 Quarq c/set (bb30) come in for some work, so i pulled out the chainset and had a quick measure against a Rotor 3d+ (which has a 30mm spindle, and on a BB30 frame runs 2x10mm spacers, on BBRight runs 1x10mm spacer, and on the Rotor 30mm bearing cups for BSA frames has no spacers) and the Sram was about 10mm shorter in the spindle 
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It wont work because the rotor crank isn’t a “true” BB30 crank. It can be put on a BB 30 frame, but so can most cranks. BB 30 cranks are made with a narrow spindle, big diameter spindle. The crank you reference is a wide big diameter spindle. The extra width is where the bearing go on a BSA frame. On a true BB30 frame the bearing go inside the frame and the cranks butt up almost against the bottom bracket shell, leaving no room for the bearings.
i had this exact question in my head about 3 weeks ago - i then had a bike with the Sram 975 Quarq c/set (bb30) come in for some work, so i pulled out the chainset and had a quick measure against a Rotor 3d+ (which has a 30mm spindle, and on a BB30 frame runs 2x10mm spacers, on BBRight runs 1x10mm spacer, and on the Rotor 30mm bearing cups for BSA frames has no spacers) and the Sram was about 10mm shorter in the spindle
Now I understand. Thanks for the info - this is all good stuff. I was definitely fixated on the BB30 diameter being 30mm and assumed that the length of the spindles were standard across different brands.
I’ve been dealing with a similar situation, a new frame with pressfit 30 BB. Sadly Quarq was in progress with the 3D+ crank when they were bought by SRAM and their production focused shifted elsewhere. SRM does produce a 3D+ crank, but sadly it’s rather pricey.
If the frame is PF 30 you should be able to find a work around for almost any crank although you may have to dig a bit to source parts.