It’s actually possible to get the SRAM 975 quarq to work on a normal BSA bottom bracket. You just need the BSA30 bottom bracket from Rotor. Both my teammate and I are using that setup, and he’s able to hotswap between his BSA training bike and his BB30 racing bike.
I thought that the BSA30 only worked with Rotor cranksets, no?
On other traditional BB30 cranksets, which are used with internally pressed bearings, wouldn’t the BSA30’s external cups be too wide for the space b/t the frame & crankarms?
Granted, you can swap the S975 b/t BSA & BB30, but that’s another story…
SRAM S900 and S975 cranksets both use the same crankarm and spindle, which are longer than the typical BB30 spindle. In fact, they can even be used with Cervelo BBright bottom brackets. Normally, to use these the S900/975 cranksets on a BB30 frame, you need spacers on both drive- and non-driveside between the crank arm and the spindle. These can be removed to be used with BSA30 bottom brackets.
The Rotor 3D+ cranksets, and even the Zipp Vumaquad cranks are similarly built.
I knew the Vuma had a longer spindle, so I assumed it would work. Lots of threads on WW & Velonews talking about how the BSA30 wouldn’t work with other BB30s, but I didn’t put 2 & 2 together in that if S975 could be swapped from BB30 to BSA for you by Quarq (http://www.quarq.com/faq), then it probably had the longer spindle as well. My only remaining question is how this longer spindle works on BB30 framesets? If the spindle is wide enough to work w/ external cups, what do you do with all that extra width on a native BB30 shell?
That’s super cool, and might have just piqued my Quarq interest. Thanks!
Per Velonews (http://velonews.competitor.com/…-right-shoe_165957):
"Finally, I’m sure you could not use Rotor’s BSA30 cups on other BB30 cranks because there would not be enough space between the frame and the crankarms for the external cups. A BB30 road bottom bracket shell is 68mm wide – the same as a BSA (English-threaded) road bottom bracket shell (both systems are 73mm wide for mountain bikes). And one of the much-hyped features of most BB30 cranks is the fact that ankle clearance is improved. In other words, most BB30 crank manufacturers have taken advantage of the fact that there is not an external bottom bracket cup taking up space and have moved the head of the crankarm inward on both sides. So you couldn’t fit the BSA30 cups in between the frame and the cranks with any crank other than Rotor. And that doesn’t even address the fact that, even if you could fit them in, the raised and ground bearing-contact surfaces on either end of most BB30 spindles would not line up with the external bearings, since they are placed to contact the inner races of bearings that are internal to a 68mm (or 73mm mountain) bottom bracket shell. "
— Lennard
The same trick can even be pulled off with the new SRAM Red Quarqs. (=
All the extra width is taken up by a spacer on the driveside, and either the integrated load adjuster+ spacer, or wave washers and spacers on the non-driveside
On the BSA30, you lose the spacer on the driveside and the load adjuster on the non-driveside; I get by with 2 thin spacers on the driveside and a wave washer on the non-driveside.
Very interesting. Might be some powertaps for sale soon. Never wanted to deal w/ it because tt bike is BSA, road bike is BB30, but now that I’ve been informed…!
I do appreciate the advice. Thank you. There are some changes I’m still going to make with the new quarq: 165mm and qrings, so it will be a Rotor.
But does this info make my SRAM more valuable? I guess it does, who wants to buy it?
Bump
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Would you be interested in trade with like new 172.5mm version?
No thanks. I’m getting a rotor 165
I can’t send private messages yet because I just registered, but I’m definitely interested and wanted to know if you could send pics of the crank (assuming you haven’t sold it yet). Email is briangartside@gmail.com
Pics are sent.
Bump. Still available. Deal fell through. Who wants it?
Bump. New price! $1300 plus shipping!
Bump.
Bump
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$1250 plus shipping. PRICE DROP! And Quarq just calibrated/checked it on 16 August. This is a great deal. Who wants it?
Can’t PM; send me an email at (slowtwitch username) @ gmail.com
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$1200 plus shipping. Who wants it. Quarq calibrated it on 16 August. Less than one year old. Works flawlessly.
Gene