Non boost XT crankset
Non boost 142mm rear.

I found chain was very sensitive to back-pedalling when first installed and took advice to move a spacer from the botttom bracket from drive to non-drive side. This has been a bit improvement BUT of course that offsets the cranks a few mm to the non-drive and I think I’m getting leg/rear triangle rub as a result (my right foot/leg turns out more than my left so more of an issue on this side anyway).

Has anyone spaced out the chainring to get the same result? I’m running a Absolute Black 30T if that makes any difference.

Was it causing you any problems on the bike, or just when backpedalling on the workstand?

I had that quite bad when putting together my first 11-speed XT build, but it wasn’t really an issue when riding.

When riding. Starting on steep climbs or part back pedalling to clear rocks and steps causing issues.

It is much better with chain line as I have it now but want to achieve the sale without offsetting the pedal position

A drop of acid?

Edit – sorry, misread the question.

Did you try a sram chain I was putting 0.1mm shim washers in there and it drove me to distraction till I put a sram chain on it and the back-pedalling thing went away ,

You can get chainring spacers – washers that go between the chainring and the spider using longer bolts. Not a great idea tho as it reduces the area of the chainring in contact with the spider. certainly do not use alloy bolts if you do this.

ie http://www.jejamescycles.com/id-outer-chainring-spacer-silver-dwp4278.html?gclid=EAIaIQobChMIwte49LCa1gIVl8myCh2WCQZQEAQYAiABEgK-N_D_BwE

Hi there,
I had the same issue when I changed to a 1×11 on a Cannondale prophet. I drilled out 4 convex washers from a set of cantilever/v-brake blocks (The smaller washer about 3-4 mm thick). I also bought a set of longer chain ring bolts as the normal bolts will not catch enough threads on the chain ring when used with the 3-4mm spacer. That almost solved the problem. I noticed when back pedaling that the chain was catching on the teeth in the shift groove on the 46t ring on the cassette because they are further back on the this ring ring. As this is made of aluminium on my Sunrace cassette I took an adjustable spanner and pulled them forward a tad and this stopped the chain catching on them, consequently solving the back pedaling problem. Sounds extreme and maybe unnecessary but you would not notice it if you looked at it. In no way has made any difference to the performance. Im’ running a Sram chain on my setup.

Which gears does this happen in? Do you have a straight(ish) chainline when in 6th gear (assuming 11sp) or 5/6th (10sp)? Are you running a narrow/wide ring?