Sram red crankset GXP vs BB30

Discuss light weight issues concerning road bikes & parts.
JScycle
Posts: 172
Joined: Wed Mar 08, 2017 11:41 pm

by JScycle

Hey Weenies,
I am looking into getting a quarq powermeter on a BB86 bike.
I have heard that I can run both the BB30 and the GXP but with different bottom brackets.
Which is better. Lighter, more reliable, more durable bearings, water resistance, preload adjustment etc

by Weenie


sungod
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Location: it's raining, it must be uk

by sungod

as bb86 is pressfit, i'd go bb30, should be lighter, probably stiffer, other factors not much in it

edit: ahhh, just noticed the bb86 shell dimensions, hadn't realised the diameter is too small for standard bb30 bearings, so better to go gxp, otherwise you end up having to use bearings with thin races or specials like the wheels mfg dual row sleeveless ones
Last edited by sungod on Mon May 07, 2018 11:43 am, edited 1 time in total.

Cemicar
Posts: 48
Joined: Mon Aug 21, 2017 7:40 am

by Cemicar

If Quarq Red BB30 has a spindle long enough for a BB86/BB386 bike, you still need to use an adapter to install it. So both are pressfit.

jacobeh
Posts: 18
Joined: Wed Aug 17, 2016 12:56 pm

by jacobeh

I personally went with the Quarq GXP version for my BB86 - as Cemicar mentioned you need to ensure the spindle is long enough since BB30 is usually made for 68mm shells as opposed to BB86's 86.5mm. Also keep in mind that normal BB30 bearing OD is 42mm and BB86 shell ID is 41mm, so another thing you need to check.

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MayhemSWE
Posts: 132
Joined: Thu Mar 12, 2015 12:44 pm
Location: Stockholm, Sweden

by MayhemSWE

The older BB30 cranks most likely will not fit at all. The latest BB386 cranks should have sufficient axle length to work with a third party bottom bracket, but the bearings will be very small with compromised durability. Personally I'd definitely go for the GXP version. (Or DUB if Sram moves over to that standard for the road as well…)

JScycle
Posts: 172
Joined: Wed Mar 08, 2017 11:41 pm

by JScycle

MayhemSWE wrote:
Mon May 07, 2018 10:47 am
The older BB30 cranks most likely will not fit at all. The latest BB386 cranks should have sufficient axle length to work with a third party bottom bracket, but the bearings will be very small with compromised durability. Personally I'd definitely go for the GXP version. (Or DUB if Sram moves over to that standard for the road as well…)
Yeh if durability is compromised i'm not sure if it's worth the weight savings, 50ish grams maybe.

Nefarious86
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by Nefarious86

GXP will have more reliable bearings.

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alcatraz
Posts: 977
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Better check your specifications. Either bb86 is right (or pf86/46 as it could be called) or bb30 is right. They can't both be right.

Guess buying could lead to headache. :lol:

/a

stuh
Posts: 22
Joined: Mon Nov 30, 2015 1:30 pm

by stuh

get a gxp with the wheel mfg thread-together BB

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MayhemSWE
Posts: 132
Joined: Thu Mar 12, 2015 12:44 pm
Location: Stockholm, Sweden

by MayhemSWE

alcatraz wrote:
Mon May 07, 2018 1:01 pm
Either bb86 is right (or pf86/46 as it could be called)
Can't see how that makes any sense as the inner diameter of a BB86 shell should be 41 mm :wink:

I do suppose it'd be easier if bottom bracket shell standards used descriptive names such as BB86 → PF41/86, BB386 → PF46/86 and PF30 → PF46/68. But then there are still assymetric/offset standards to deal with as well like BBright and probably others…

Hexsense
Posts: 463
Joined: Wed Dec 30, 2015 12:41 am

by Hexsense

alcatraz wrote:
Mon May 07, 2018 1:01 pm
Better check your specifications. Either bb86 is right (or pf86/46 as it could be called) or bb30 is right. They can't both be right.
are you confuse BB standard: BB86 which is 86.5mm wide, 41mm ID with PF30 which is 68mm wide 46mm ID and BB30 which is 68mm wide 42mm ID?
and crank spindle standard: GXP (24mm step down to 22mm diameter, long enough for 86.5mm BB) and BB30 which is 30mm diameter, long enough for 68mm BB and BB386 (which sometime will be called as long spindle BB30)?

I read it like you don't get what you are saying.

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IrrelevantD
Posts: 291
Joined: Sun Nov 29, 2015 5:47 pm
Location: Near DFW Airport

by IrrelevantD

JScycle wrote:
Mon May 07, 2018 5:32 am
Hey Weenies,
I am looking into getting a quarq powermeter on a BB86 bike.
I have heard that I can run both the BB30 and the GXP but with different bottom brackets.
Which is better. Lighter, more reliable, more durable bearings, water resistance, preload adjustment etc
Might be easier if you told us what bike you have. That way people who actually have one can chime in. Assuming it's a press-fit BB86 bottom bracket, you should be able to find a BB to go either way.

IE: my Giant Propel came with a Shimano PF86 BB (essentially the same as GXP aside from NDS inside diameter), I replaced it with a Wheels Mfg. bottom bracket. When I replaced that with a Spec. Allez Sprint, which came with BB30, I was able to use the exact same Wheels Mfg. BB out of my Propel.

So tell us the bike, and I'm 100% sure someone will tell you exactly what will work.
* There is a 70% chance that what you have just read has a peppering of cynicism or sarcasm and generally should not be taken seriously.
I'll leave it up to you to figure out the other 30%. If you are in any way offended, that's on you.

alcatraz
Posts: 977
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

If it is bb30 compatible it can't be bb86 (and vice versa, gxp/hollowtech in bb30 shell is unwise). That's my point.

Why is everyone assuming bb30 is the mistake and bb86 is correct. How can you be sure?

Better double check your frame's bb shell.

I didn't know bb86 had a 41id. Thanks. It's still incompatible with bb30 though.

/a

Cemicar
Posts: 48
Joined: Mon Aug 21, 2017 7:40 am

by Cemicar

Some "BB30" cranks have long spindle (so they may be BB386 indeed) and you can insert those into BB86 frames. BB86 is BB386 compatible with third party adapters although the bearing balls become a tad too small as mentioned.

But yeah I agree it doesn't hurt to know the specific bike name.

p.s.
I'd go with GXP simply because it might resell higher. Plus, I'm not sure Quarq BB30 is significantly lighter than GXP. Don't remember Quarq ever claims weights per BB as SRAM did.

jlok
Posts: 557
Joined: Tue Jun 30, 2015 3:30 am

by jlok

The biggest failure of the DZero website is that they state it as BB30 instead of BB30/BB386. So much confusion for the consumers.

The crank is BB386 and is adapted/shimmed to BB30. I'd still get the GxP tho if I have BB86 frame for the bearing life.
Giant Propel Advanced SL Disc 1 < Propel Adv < TCR Adv SL Disc < KTM Revelator Sky < CAAD 12 Disc < Domane S Disc < Alize < CAAD 10

by Weenie


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