

I just changed my bike over to 1×12 from 2×12 I’m running a shimano grx 820 crank with an alugear 40 tooth chainring, a shimano grx rx 822-sgs derailleur and a sunrace 11-51 cassette. The chainline is terrible in the 51 cog. Is this normal or is my spacing off?
by PuddingEntire9852
12 Comments
Correction it’s a grx fc-rx810 crank. Is this the wrong crank for a 1×12??
https://preview.redd.it/nvx4tt72utog1.jpeg?width=2944&format=pjpg&auto=webp&s=9cd41de1638992c19eb5080bc24f7afab149cf91
That’s pretty much how it is supposed to be. If you have some space left between Chainring and chainstay you can try to move the Chainline closer but that chainline is far from other (way worse) setups I’ve seen.
Sadly yes. I’m dealing with the same thing on my Force/GX mullet, and I always cringe when I see it.
That said, you do appear to have a lot of clearance between the chainstay and chainring, your spacing might be off
Edit: just looked at first pic again, chainring/chainstay clearance looks fine imo
One of the reasons I don’t like 1x for my gravel or road bikes. I don’t have any issues shifting a modern SHIMANO front derailleur. SRAM on the other hand…
This is one of the key compromises you make going 1x. Your chainline can get really extreme in the larger cogs. You just have to accept some amount of noise and jankiness. As long as it shifts well and doesn’t skip under load it’s working as intended.
Maybe run some chain ring spacers to get the ring inbound. Also how often are you going to be in that gear? If you are like me you end up on the other side of the cassette more often so maybe it’s not a big concern.
Also, it may be the angle I’m looking at, but it would appear that your chain is a little too short?
Yeah, normal. As much you can adjust a little inward but only about 5mm. Chainline must be around 48mm, I can’t remember the exact number.
Better that way than having a chain rubbing in the smallest sprockets.
I have a few mm to play with using chainring spacers but then my 11 cog would be worse. I think I’ll send it and see how it rides.
Also I measured the chain per shimano instructions.
Is your derailleur compatible with a cassette that large?
What pedals are those?