Struggled in the mud uphill over the weekend, so lower gear would be good. Have a 1×9 set up, 32T front and 34T rear on Middleburn RS7 Uno. Can I just buy a 29T Duo ring and run that as a single up front? Any chainline issues? Any other issues?

Cheers

Don’t see any reason why not, but you won’t have the chain retention benefits of a N/W. But as you’re already running 1x I guess you’ve already overcome that.

I wondered about the same thing, but ended up buying a Middleburn spider and using a 4 bolt NW 30T ring (Hope etc). Also lets you rotate the ring to even out the wear (which the UNO didn’t let me do).

won’t have the chain retention benefits of a N/W

Why not? Can’t he just get a 29t NW?

Why not? Can’t he just get a 29t NW?

Not sure if you are being sarcastic or not….

Give Middleburn a call/email and they can advise you best. I think there may be chain line issues, as the Duo ring is obviously aligned to give the best possible chain line as a two ring set up.

Why not? Can’t he just get a 29t NW?

He could, but he was specifically asking about

a) 29t
b) Duo chainrings

The first precludes N/W, the second was a setup that middleburn made that mounted the inner on a spline and the outer was bolted to the inner, hence the availability of smaller sprockets than 30t.

Thanks all. I do have a Middleburn spider so a NW chainring might be good to get rid of my chain keeper – numpty qn, do I need a NW specific chain?

The inner ring of a Duo has a different chainline to an Uno, so won’t be quite ideal, however if you already have one it might be worth a trial. It will have shifting ramps which with a single set-up won’t be any use, and may actually be an impediment, so a specific ring would be better.

Cheers, Rich

I have a 27 & 29t inner duo rings that I experimented with and continue to use.

The inner ring doesn’t have any shift pins ramps etc as these are on the outer ring of the set up, in that your shifting up to a larger ring.

I’ve found no chain line issues with 9 and 10 speed set ups although I am some would say its less than ideal. That said chain line can be corrected a little with use of different width BBs presuming square taper.