Seeing as the middle ring is now effectively in the place where the big ring would sit? (or am I wrong?).

If the chainline would be out- how would you compensate??

(SLX double chainset) and 30T narrow wide chainring.

Click me for advice

Oh and yes you are wrong – the middle ring is in a different position to the old position of the outer ring. The point of a dedicated double like on a road bike too is that you can use the full range of the cassette with no chainline issue. It’s just the same as never using the granny ring

Re-position the single ring to the inside of the spider will effectively place the single ring between the original two rings, which I think is where the chain line for a double is measured from.

Although I may be incorrect.

Good to see you two have made up.

Per slackalice – I never even considered not mounting the single ring to the inside of the spider (i.e. into the middle ring position (near enough). Logically this would be favourite as the middle ring on a triple should definitely have the best chainline – I suspect the same for a double although the ‘logic’ does fall over(?)

Ask Rob if you need advice on chainring bolts for your single ring – he is very helpful 😉

I ran my single ring in the outer ring position on my XTR Race double, the chainline was slightly further out than on a middle ring position on a triple, but it worked fine.

Using a single ring (Race Face narrow/wide) mounted on the inside face of my XT double. Seems to work fine with no issues, although I know theres a bit of rub as the side plates of the chains look a bit worn.
Can’t remember if I used the original chainring bolts or some I had kicking around.

Mike

If the chainline would be out- how would you compensate??

I’ve gone from double to single and the chainline was way off. I switched the bb spacer.