bonsai171

Hello,

Been looking at gravel bikes, and was wondering if it would be possible to change a GRX FC-RX600 1x crankset for a direct mount crankset? If so, which ones would work? I would like to get very low gearing (maybe 22 gi or so).

Thanks,

Dave

gus6464

Buy a SRAM DM crank and then you can use any spider you want. I've used 32t up to 44t on a Rival DM crank.

bonsai171

How can you tell which cranks are direct mount? Are the apex 1x cranks direct mount?

Dave

gus6464

Apex is not DM. You will need Rival and above. Another option is the old new stock Rival 22 cranks. Those are DM. I scored one on ebay for $80 a couple of months ago for a build brand new so you just have to look.

What length do you need?

bonsai171

Crank size is an interesting question. Got a road bike, fixed gear, and mtb. They all have a 170mm. Some of the bikes I've looked at spec a 172.5mm crank in my size, others spec a 175! Should the crank length be specd to match the crank on the bike?

​​​​​​Also, can you explain how to pick a chainring offset? Cranksets seem to be more and more complicated then ever before!

Dave

wsteve464

If you go from the GRX to the Sram you will also need to change the bottom bracket to a Sram GXP BB. You are looking for roughly a 34/42 to get 22 gear inches. If you can handle the wider Q factor you can go to a 1x MTB crankset.

Since you are in the looking stage maybe consider a 2x chainring

bonsai171

The bb change makes sense. The q factor doesn't bother me. I haven't looked to see if the SRAM GX crank is direct mount, but would consider something like that.

I haven't really considered a 2x, would that work with a SRAM 11-42 cassette? Just looked at the Rival 22 crankset, lowest gearing offered is 46/36. Could I change the 36 to a 32?

Dave

wsteve464

The GRX 600 is a 46/30 chainring set. Yes the crank will work with the SRAM cassette as long as you have the right hub the SRAM 11 speed 10-42 cassette requires an XD driver on the hub but most good hubs (DT Swiss etc) allow you to change out the driver for $60 or so. SRAM 11 speed 11-** cassettes use the same driver as Shimano AFAIK.

For me, old and slow I have all my bikes set up 2x. I'd rather have the low gears and not need them than the other way around.

bonsai171

Is the SRAM force crankset in this link direct mount?

https://www.bikesdirect.com/products/...oadbike-xx.htm

Might as well get the bike with a direct mount chainset and an upgrade to Force for only $200.

Dave

gus6464

Crank is a preference thing. I am 6ft and I run 165mm cranks on all my MTBs for example but on drop bar I like 170/172.5. Chainring offset for SRAM you got 3 options:

0 - bb30
-6 - gxp
-3 - boost

Since it looks like you got GXP you will be looking at a -6 offset chainring.

gus6464

That kind of coin on a BD bike is nuts to me. You're in Warbird territory on clearance.
https://www.treefortbikes.com/Salsa-...-1-Gravel-Bike

bonsai171

That's much better. I like that, just wish it was a different color. Know of any other deals?

Dave

gus6464

Not in the 2k range. That Warbird is the best you gonna get. The white frame is cheaper but with Tiagra build.

bonsai171

It is a nice color, just not one of my favs. Going to give it serious consideration, it might grow on me. Not very familiar with tree fort though, are they a reputable shop? From what I can see they are based in Michigan? Free shipping is pretty sweet, do they warranty the bikes?

Dave

gus6464

The warranty is from the manufacturer not the shop so in this case salsa.

bonsai171

Just wanted to say thank you for the link! I just ordered the 57.5 cm Warbird. Very excited!

Dave