Lightweight crankset for Emonda, BB90

[Pax]

I'm looking for some lightweight crankset for my 2017 Emonda SL 6, BB90.
Corrently running Ultegra 6800.
Don't need power meter.

Any sugestion?

[VTR1000SP2]

SRAM Red GXP if you don’t care about mixing up the brands


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[alcatraz]

If you one day would like a single sided (very light) powermeter go with dura-ace crank.

If not go with sram red gxp. Expensive lightweight stages power meter available. (sram chainrings are heavy = can upgrade later)

[hannawald]

Which chainrings are lighter and works flawlessly? Sram 50/34 are 125/30g..
Extralite chainrings are light but heavily critisized for making troubles. Stronglight outer chainring is claimed 80g, but is 105g real..Praxis Works will save 17g in total. I don't know about TA Specialites, how they work..

[Mep]

Lightning is also an option and would save roughly 50g, but not sure how the ride quality and stiffness would compare to Red.

[RyanH]

For compact and standard, the Cannondale MKV are the best. 103g for compact with bolts and I think 120g for standard with bolts.

[alcatraz]

No chainrings work flawlessly and people differ at how good it needs to be.

Extralite works better than many original chainrings, but not as good as the best. For me having tried poor shifting setups and gotten used to their quirks, extralite rings perform beautifully and I'm unlikely to switch.

They are an expensive upgrade and comparing them to their price siblings they will not perform great. They just perform ok.

I picked mine up second hand at a steal price so I don't make that comparison.

[Pax]

Thanks for all the answers.
I think the Sram could be a good option...
Can someone tell me the weight saving between the ultegra 6800 50/34 and the Red GXP cranks with the same rings?

[alcatraz]

6800 50/34 681gr (shimano claim)

sram gxp 408gr + 8gr bolts + 128 + 28 = 572gr (measured but citing numbers from memory, might be off a gram or two)

If you put extralites on the crank it weighs in at ~515gr.

Pay attention to the year make of that gxp crank. They vary in weight sometimes. They became heavier at one point. Don't know how they are today though.

[hannawald]

I have current version of red gxp 50/34 172.5 and it is indeed 570g weighted by myself. It is the lighter version with non removable spider, so you can't fit spider powermeter. i would buy extralite chainrings but seems to cause problems to many:(

[Pax]

Thanks for your reply.
I'm not an expert in mechanics...
Is there any tuturial of how to mount the sram crankset in the BB90?

[VTR1000SP2]

Buy the crank and bb90 GXP bottom bracket then take it to a shop. Doesn’t sound like you should do this yourself.


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[Cemicar]

GXP installation indeed can be easy. You even don't need to replace a BB once you manage to get a reducer sleeve (24 to 22) and a wave washer, the latter of which is not always required. Still I agree you'd be better off asking a LBS, especially since this replacement will worsen the shifting performance if still passable.

[alcatraz]

I can confirm good shifting of gxp red on a trek domane bb90 with extralite chainrings and a shimano bb + reducer sleeve + wavy washer. It's important that the wavy washer is nearly completely compressed. For me I didn't need any spacers. It depends on the thickness of your dust covers and the bb shell tolerances.

Just a matter of spacing away most of the slack.

[Calnago]

Trek likely has a BB “kit” for the Sram Gxp crank which will ensure correct spacing, compression, etc. you should just get it. They’re not overly expensive.