Not that it really matters but I’ve just replaced my Shimano XT 44 tooth outer chainring with a 44 tooth Middleburn Slickshift Hardcoat ring. As I have one of those Inbreds with bridgeless, ultra wide chainstays with very tight clearance, I put zipties behind all the rings (there’s probably not much point behind the big ring as I’ve never had ‘suck there). The original Shimano ring cleared the ziptie, the Middleburn one touches it (so it came off). Perhaps it’s the Hardcoat coating.

Did you buy the specific Middleburn XT ring?

The offical responce from Middleburn about them is that:
“Shimano changed the shoulder that the ring sits on to from 90mm to 88mm and the chain line is 0.6mm closer towards the outer ring.”

I’ve just measured mine & the Middleburn is wider but only by 4 thou.

Zippy, it’s on an Octalink M752 chainset (Hollowtech 1). The CRC site says that the Middleburn XT chainrings are for Hollowtech II chainsets only.

fair enuff, if you really interested give middleburn an email – they tend to answer all my inane enquiries..

I’m having issues with the ring – http://www.singletrackworld.com/forum/topic/middleburn-chainring-problem in the middle ring and smallest cog with the chain catching the shifting pins, I’m not sure whether this is down to the Hardcoat coating making the ring thicker.