crankset and group compatibility

[jmcabellom]

hello everyone,
I want to use a shorter crankset, one 160mm.
the cranks that I have found are for 12 speeds
my groupset is a Tiagra 4600 10 speed
will it work?
thanks for your help!!!

[kbernstein]

Post is a little unclear.
 Are you looking to swap just the cranks and use the chainrings from your 4600 crankset? If so, which 12 speed cranks? If newer shimano eg. R7100, no because Tiagra 4600 is 5bolt and newer shimano cranks are 4 bolt. If it's a third party crankset and it has the right BCD and 5 bolts, maybe

If you are replacing the entire crankset wiith shimano R7100 12 speed and the question is "will these 12 speed chainrings fit on a 10 speed chain/groupset?" the answer is yes. Officially shimano doesn't recommend it, and it won't be optimal, but it's not a big deal and 10 speed chains work alright on 12 speed chainrings

[jmcabellom]

Dear kbernstein,

thanks for your help.

Idea it would be to replace the whole crankset.

i was checking: Ultegra FC-R8100 Crankset - 2x12-speed  https://www.bike24.com/p2509119.html?source=SRP&indexName=production_SEARCH_INDEX_EN&objectId=509119&queryId=0c3283d080e7e37fd6ba7d8595717b61&userToken=1acda5d1-fe69-4752-adb1-a203bdc09359&sku=1739983

as i was doubting was checking other brands that advise compatibility with 10s groupsets as:
FSA OMEGA MODULAR MEGAEXO crankset https://shop.fullspeedahead.com/en/type/cranksets/cranksets/road-gravel/omega-modular-megaexo-crankset

ROTOR INpower Road Gloss Crankset https://rotorbike.com/en-eu/inpower-road-gloss-crankset.html

PRAXIS ZAYANTE CARBON-S https://praxiscycles.com/es/product/zayante-carbon-s/

Do you think should i go with shimano or maybe the other alternatives? what do they think the others?

Thanks for your help!!

[kbernstein]

I would prefer shimano over all these options. Personally 105 r7000 because it:
1. Has a slightly narrower chainring profile as it's for 11 speed
2. Is not much heavier than ultegra, only about 35 grams iirc
3. Is DIRT cheap these days. I would recommend the gray market as plenty of people take off cranks from their new bikes. You can likely find it under 80eur
4. Forged and not bonded so it doesn't suffer from crank failures like ultegra r8000 (this is fixed on r8100 though)
If you really want ultegra, r8100 is good. avoid r8000 if you live somewhere humid or on the coast. Praxis and FSA cranksets are just not as good. Not bad but a snob pick for more money, no point. Rotor cranks are better but pricey

[jmcabellom]

Thank you soooo much kbernstein