grx 1x with road crankset

[PoorCyclist]

GRX Crank and Front Derailleur
Shimano GRX cranksets feature a +2.5mm outboard chainline, which improves rear tire clearance, making room for wide gravel tires. This also means that the GRX crank’s Q-Factor is +2.5mm wider on each side compared to Shimano road cranks. Due to the wider crank and chainline, GRX cranks must be used in conjunction with a GRX front derailleur for 2x11 and 2x10 drivetrains.

Does anyone know if I put a road crankset will I have problem with 1x? The chainring will be move inwards 2.5mm, q factor -5.0mm (which is good for me)
I don't think the chain will touch the tire.

Don't know about the RD parallel o gram etc.

[jfranci3]

GRX cassettes are MTB freehub fit, but you just put a spacer on the road freehub. The MTB cassettes are spaceed 3.74 vs 3.9mm, but Shimano lists R7000 cassettes as compatible. https://bike.shimano.com/en-US/product/ ... speed.html
You can probably leave teh chainline alone, as you'll want the efficency in the smaller cogs being 1x.

[PoorCyclist]

Mostly I am riding the largest 3 cogs the whole ride. I rarely use the smaller cogs.

The optimization I wanted is not just chain angle, the grx crank is a bit wide for me, my shoes rub the crank and I have the lower my saddle to compensate for the Q. I don't have problem with road cranks.

[robertbb]

GRX cassettes are MTB freehub fit, but you just put a spacer on the road freehub.

Umm, there's no "GRX" cassette.

[Omiar]

I switched from full GRX 2x11 setup to 1x11 with Power2Max/Rotor Aldhu-R 24mm/Rotor 1x chainring combo.
Would be probably the same with Rotor spider.

[PoorCyclist]

I switched from full GRX 2x11 setup to 1x11 with Power2Max/Rotor Aldhu-R 24mm/Rotor 1x chainring combo.
Would be probably the same with Rotor spider.

with the 1x now are you using 2x GRX or 1x GRX RD ?
their geometry is different

[Packs]

GRX cassettes are MTB freehub fit, but you just put a spacer on the road freehub. The MTB cassettes are spaceed 3.74 vs 3.9mm, but Shimano lists R7000 cassettes as compatible. https://bike.shimano.com/en-US/product/ ... speed.html
You can probably leave teh chainline alone, as you'll want the efficency in the smaller cogs being 1x.

The MTB (and 11-34) cassettes overhang the free hub at the spokes, so the cogs are all in the same place as road, i.e. you don't need to adjust a rear mech when changing between road/MTB cassette.
I imagine there'll be slightly more cross chain on the smaller cogs but it will work fine.

[Packs]

GRX cassettes are MTB freehub fit, but you just put a spacer on the road freehub. The MTB cassettes are spaceed 3.74 vs 3.9mm, but Shimano lists R7000 cassettes as compatible. https://bike.shimano.com/en-US/product/ ... speed.html
You can probably leave teh chainline alone, as you'll want the efficency in the smaller cogs being 1x.

The MTB (and 11-34) cassettes overhang the free hub at the spokes, so the cogs are all in the same place as road, i.e. you don't need to adjust a rear mech when changing between road/MTB cassette.
I imagine there'll be slightly more cross chain on the smaller cogs but it will work fine.

[Omiar]

I switched from full GRX 2x11 setup to 1x11 with Power2Max/Rotor Aldhu-R 24mm/Rotor 1x chainring combo.
Would be probably the same with Rotor spider.

with the 1x now are you using 2x GRX or 1x GRX RD ?
their geometry is different

Still the same GRX RX810.
Using GRX RX812 would just allow up to 42T but I have no need for that. Im fine with 30T.

[PoorCyclist]

Here is an update, I removed the GRX crank, installed SRAM GXP crank with wolftooth 1x ring. 1x GRX derailleur.
The chain moved towards the frame (measured at the seattube) by a little over 3mm.

There is NO tire to chain clearance issue with 700 x 40c tires which is the biggest tire I can fit. 650b could fit a wider tire I suppose, not sure if I agree with Shimano making their cranks wider to address an issue 95% of bikes does not have. I know SRAM put out a wide crank and wide FD, but at least you have a choice.

No problem in any cog. I can absolutely backpedal in any cogs now. Since I moved the chainline inwards, the interaction with the smallest cogs was a concern. The result is only the 2 smallest 2 cogs make a little "tick" when back pedalling to re-align itself.

Riding here is very steep so chain being straighter in the biggest cogs makes it more effecient in my use case.

Why is backpedalling a big deal to me? Well, I need to pick up the pedal with my shoe from the bottom about 1/4 turn to start riding off. When it's in the bigger cog if the chain drops to one cog lower, the derailleur is still in the big cog, you jam the chain, you do not want to force it with your leg because it will bend stuff. When you need a take a stop riding up hill and try to restart, the chain drop off, and since you cannot force it, you have to get off the bike, lift it, spin the bike and remount again. That was the most frustrating thing with this new 1x system.

My shoe rub is gone and I was able to raise my saddle by 15mm, before, due to the wide q-factor I was forced to lower my saddle because otherwise my legs are like this / \ , with the lower saddle it's mostly quads action which can burn me out easily. Now the leg alignment to pedals are very natural like other road bikes.

The 200g weight loss is a very nice bonus as well.