SRAM Etap crankset with BB30 compatible with Scott Addict SL (BB86)?

Discuss light weight issues concerning road bikes & parts.
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wootenlakeguy
Posts: 29
Joined: Sun Jun 20, 2010 6:55 am

by wootenlakeguy

I'm really confused by all the BB standards. In fact, I got burned about a year ago when after buying a Cannondale SISL2 crankset for my Addict SL, I found that it was incompatible with no acceptable solution for retrofitting. After losing almost $200 during resale, I'd like to avoid this issue again.

I recently switched to SRAM Etap with their upgrade kit on my Scott Addict SL. I love the improved shifting so much that I'm now considering changing the existing Dura Ace 9000 crank set for the new SRAM Etap crank set primarily for the potential of dropping about 80 grams weight but also to give the bike a more homogenous look. However, if I have to use the GPX configuration to match the BB86 specification of my Addict, the weight savings would be negligible. I only achieve the weigh savings with the BB30 version of the Etap crank set.

Is the ETap BB30 of the SRAM crank set compatible with my Scott Addict SL? If not, are there any adapters or simple modifications available that don't reduce BB bearing durability?

I appreciate your reply.

by Weenie


mrlobber
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by mrlobber

Any "true" BB30 crank will not work on your Addict because the crank spindle is too short (examples are SISL2, Specialized).

You can use either any 24mm axis crank (Shimano, Sram GXP, Rotor 3D) or 30mm axis cranks with longer spindle, such as Rotor 3D+, FSA BB386 (or any other crank which is labeled as "BB386"), THM Clavicula :twisted: . By using 30mm crank, you will need different BB bearings too.

topflightpro
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by topflightpro

Sram offers some of its "BB30" cranks with a long spindle that can be fit onto BB86 frames and some with a short, BB30-frame-only spindle. I am not sure whether the eTap crank comes in the long spindle BB30 version. Even if it did, I would suspect the weight would be closer to the GXP.

RyanH
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by RyanH

Bearing durability with a 30mm spindle is going to be lower since the shell is a smaller ID so they have to run small bearings and usually run two on each side. It's not ideal.
Strava
Current Stable. The Snob Machine
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Valbrona
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by Valbrona

topflightpro wrote:Sram offers some of its "BB30" cranks with a long spindle that can be fit onto BB86 frames and some with a short, BB30-frame-only spindle. I am not sure whether the eTap crank comes in the long spindle BB30 version. Even if it did, I would suspect the weight would be closer to the GXP.


But they give a wider chainline for 135 OLD disc brake.

wingguy
Posts: 3520
Joined: Thu Mar 08, 2012 11:43 pm

by wingguy

wootenlakeguy wrote:Is the ETap BB30 of the SRAM crank set compatible with my Scott Addict SL?

The SRAM BB30 crank is effectively the same system as the SISL2 crank, with the same compatibility problems.

The GXP version is the native fit designed for the BB86 frame.

grover
Posts: 1108
Joined: Mon Jul 26, 2004 1:06 pm

by grover

By the numbers it can be installed. But I'd stronly advise against it. It will not be centred in the frame. It will be 3-4mm towards the non-drive side with a chainline 3-4mm narrower than intended giving crappy shifting. You may also run into problems with the drive side crankarm hitting the chainstays or the non-drive side crankarm rubbing on the bottom bracket shell.

The Quarq powermeter version of the Red22/eTap crankset has a longer spindle and this can be installed in your BB86 shell correctly using a bottom bracket that his bearings to suit a 30mm spindle. It will involve using a different orientation of spacers though that will need to be purchased seperately. Having the powermeter will obviously make it heavier though.

As said above, using a 30mm spindle crankset in a BB86 shell is a bad idea. Your bearing life will be horrible. Keep your DA crankset or go with the GXP version of the Red22/eTap crankset.

by Weenie


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