Use Sram Red (BB386) Chainset in Supersix Hi Mod (PF30a)

Discuss light weight issues concerning road bikes & parts.
HillClimbTom
Posts: 4
Joined: Thu Aug 16, 2018 7:10 pm

by HillClimbTom

I have just bought a 2016 supersix evo hi mod frameset and I would like to use my sram red bb386evo chainset. What are my options for bottom brackets? I don’t really want to buy a new chainset as this has my Quarq fitted and finding an 8 bolt sram red gxp crank seems impossible! Cheers

by Weenie


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Beaver
Posts: 499
Joined: Wed Aug 18, 2004 6:06 pm
Location: Lower Saxony - Germany

by Beaver

Easiest way: https://shop.fullspeedahead.com/en/adap ... b30a-frame

But I killed my bearings with these in no time, too much force from the side.

Maybe angular contact ball bearings will last longer.

Karvalo
Posts: 39
Joined: Fri Aug 10, 2018 6:40 pm

by Karvalo

It's a 30mm spindle in a PF30 frame, so any PF30 BB is fine as long as you have the right spacers. Spacers for all types of frame should have come with the crank if you bought it retail, if it was OEM spec on another bike you may need to get the right ones from a SRAM dealer. You should need the 13mm spacer on the DS and a preload adjust ring (not wavy washer) on the NDS.

Potentially you could use the C-Bear PF30A-86-R which has the DS 13mm spacer built into it, so you just need the BB and NDS preload ring.

NiFTY
Posts: 1187
Joined: Sat May 26, 2012 11:26 pm

by NiFTY

Just need spacers.
Evo 5.02kg SL3 6.77 Slice RS 8.89 viewtopic.php?f=10&t=110579" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

hambini
Posts: 294
Joined: Tue Nov 15, 2016 8:13 am

by hambini

Karvalo wrote:
Thu Aug 16, 2018 10:42 pm
It's a 30mm spindle in a PF30 frame, so any PF30 BB is fine as long as you have the right spacers. Spacers for all types of frame should have come with the crank if you bought it retail, if it was OEM spec on another bike you may need to get the right ones from a SRAM dealer. You should need the 13mm spacer on the DS and a preload adjust ring (not wavy washer) on the NDS.

Potentially you could use the C-Bear PF30A-86-R which has the DS 13mm spacer built into it, so you just need the BB and NDS preload ring.
I don't think this will work.

PF30A is not symmetrical , drawing here

https://www.hambini.com/download/PF30AShell.PDF

if you put 13mm on drive side only, the chainline will be off.

Assuming the target bearing spacing distance is 90mm (most are), you would need 11mm on the drive side and 6mm on the non drive side.

73+11+6=90

If the original poster's crank is truly 86.5mm then they would need 9.25mm on the drive side and 4.25mm on the non drive side.


Hambini

Karvalo
Posts: 39
Joined: Fri Aug 10, 2018 6:40 pm

by Karvalo

hambini wrote:
Fri Aug 17, 2018 12:48 pm
I don't think this will work.
Page 13

https://www.sram.com/sites/default/file ... kets_0.pdf

hambini
Posts: 294
Joined: Tue Nov 15, 2016 8:13 am

by hambini

Karvalo wrote:
Fri Aug 17, 2018 3:07 pm
hambini wrote:
Fri Aug 17, 2018 12:48 pm
I don't think this will work.
Page 13

https://www.sram.com/sites/default/file ... kets_0.pdf
I looked at that and something doesn't quite add up.

Original Poster said he had a BB386 crankset which is a 86.5mm or 90mm bearing spacing. The SRAM install manual you have listed shows an extended (wide) BB30 crank which I believe is 92mm and furthermore OP has a PF30A bike, so the non drive side will not be the same as PF30.

I'd suggest the original poster measure his bearing spacing.

Valbrona
Posts: 1504
Joined: Fri Oct 28, 2011 3:25 am
Location: United Kingdom of Great Britain and Northern Ireland

by Valbrona

13mm spacer on DS.
Preload collar on NDS, including the thin steel washer.

One assumes SRAM cranksets with the extra long 30mm axle are not exactly the same as BB386 cranksets.

https://www.sram.com/sites/default/file ... kets_0.pdf

Karvalo
Posts: 39
Joined: Fri Aug 10, 2018 6:40 pm

by Karvalo

Original Poster said he had a BB386 crankset which is a 86.5mm or 90mm bearing spacing. The SRAM install manual you have listed shows an extended (wide) BB30 crank which I believe is 92mm
Yes, it is the Sram "Carbon Arm Removable Spider" chainset referenced in that manual. This is Sram/Quarq's BB386 chainset (what they call a BB386, anyway). The OP says he has the Sram Red BB386 chainset. This is that chainset. There is no other chainset in existence that matches the description.
furthermore OP has a PF30A bike, so the non drive side will not be the same as PF30.
Yes, and page 13 of the manual has spacing instructions for both PF/BB30 and PF/BB30A. These instructions are side by side in the same table, which makes it very easy for you to notice that the instructions are not the same.
I'd suggest the original poster measure his bearing spacing.
I'd suggest he follows the manual instead of overcomplicating things.

hambini
Posts: 294
Joined: Tue Nov 15, 2016 8:13 am

by hambini

Karvalo wrote:
Fri Aug 17, 2018 8:16 pm
Yes, and page 13 of the manual has spacing instructions for both PF/BB30 and PF/BB30A. These instructions are side by side in the same table, which makes it very easy for you to notice that the instructions are not the same.
You must be able to see things which I can't. PF30A is not listed anywhere.

Also SRAM do have/had cranks which are 86.5mm, it depends on model year, they are more rare.

Karvalo
Posts: 39
Joined: Fri Aug 10, 2018 6:40 pm

by Karvalo

hambini wrote:
Fri Aug 17, 2018 10:09 pm
Karvalo wrote:
Fri Aug 17, 2018 8:16 pm
Yes, and page 13 of the manual has spacing instructions for both PF/BB30 and PF/BB30A. These instructions are side by side in the same table, which makes it very easy for you to notice that the instructions are not the same.
You must be able to see things which I can't. PF30A is not listed anywhere.
As far as spacers are concerned, BB30A and PF30A are the same thing, just as BB30 and PF30 are the same thing. BB30A spacing instructions are on that page, therefore it tells you how to space a PF30A as well, because it will be the same. Agree or disagree?
Also SRAM do have/had cranks which are 86.5mm,
A SRAM Red branded crank that can take a Quarq add-on, which is all information contained within the original post? No, they do not. They may have an S900 series from whenever-ago with a 30x86.5, but that's clearly not what the guy is asking about.

hambini
Posts: 294
Joined: Tue Nov 15, 2016 8:13 am

by hambini

Karvalo wrote:
Fri Aug 17, 2018 8:16 pm

As far as spacers are concerned, BB30A and PF30A are the same thing, just as BB30 and PF30 are the same thing. BB30A spacing instructions are on that page, therefore it tells you how to space a PF30A as well, because it will be the same. Agree or disagree?

Looks like I wasn't imagining things and PF30A is not listed.

And for the record, I have seen SRAM red cranks with narrow axles. They are rare but they exist. A bike team I supply has got 6 of them.

I'm trying to give the original poster sound guidance with the advice to measure his axle and then verify exactly what he has. If you think looking in a manual and presuming everything to be exactly as is printed in a pdf you are very much mistaken and I would say slightly short sighted.

Hambini

grover
Posts: 1136
Joined: Mon Jul 26, 2004 1:06 pm

by grover

The difference between BB/PF30 and BB/PF30A is an additional 5mm shell width on the non-drive side.

The drive side does not change. So whatever spacers intended for BB/PF30 is what you use for BB/PF30A. In the case of the SRAM removable spider crankset that means a 13mm spacer.

The install difference is only on the non-drive side. The crankset comes with a 5mm spacer and a threaded preload ring. Remove the 5mm spacer and install with preload ring only.

Valbrona
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Joined: Fri Oct 28, 2011 3:25 am
Location: United Kingdom of Great Britain and Northern Ireland

by Valbrona

error post

by Weenie


Karvalo
Posts: 39
Joined: Fri Aug 10, 2018 6:40 pm

by Karvalo

hambini wrote:
Fri Aug 17, 2018 11:19 pm
Karvalo wrote:
Fri Aug 17, 2018 8:16 pm

As far as spacers are concerned, BB30A and PF30A are the same thing, just as BB30 and PF30 are the same thing. BB30A spacing instructions are on that page, therefore it tells you how to space a PF30A as well, because it will be the same. Agree or disagree?
Looks like I wasn't imagining things and PF30A is not listed.
If you don't know how to take spacing instructions for BB30A and apply it to PF30A then I honestly don't know how else to help you.

I would guess the problem isn't that you can't see the information (it's really, really obvious), it's that you're choosing not to understand it.
And for the record, I have seen SRAM red cranks with narrow axles.
Most Sram Red cranks have narrow axles, but they're a fundamentally different type of Sram Red crank. What type are you talking about?

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