Middleburn slickshift rings have ramps for...er.. slick shifting BUT, and heres the theory, the teeth are thinner where the ramps have been cut out potentially wearing out quicker. So will the non slickshift last longer because of the thicker teeth - make sense or nonsense??
makes sense, load spread over a greater area. I recently fitted some slickshift hardcoat rings to a raceFace turbine crank. The shifting was so bad, the place I bougth them from gave me my money back! Worst rings I've ever used.
Maybe, but while I wore out my Shimano rings in less than a year of weekend use (say once per week), the Middleburns hardpoint/slickshifts are still running after 18 months of heavier use (say 3 times per week).
And they seem kinder on chains...
I've sworn by them in the past, but have to admit; they don't shift very well.
It's a logical theory.
But I think in practice the difference is prolly negligible and there are more critical variables.
I've used Slickshifts before and found they didnt shift as well as other brands but lasted longer. Mind you that coulda been because I didn't shift rings as much using them because it was such a noisy graceless palaver 😕
I've run a 2nd hand set of hardcoat slick shifts for a few years now on my commuter.
Prob gets cleaned a once/twice a year when fettling, and still working fine n dandy - not really comparable to gritty/muddy MTB scenarios but I think they've been superb.
I guess the shift efficiency/feel will depend on the kinda mud/dirt/crap/abuse that is particular to your riding location.
My tuppence worth.
I bought a slickshit/hardcoat ring and really didn't get on with it. It was an outer ring and much thicker (possibly due to the hardcoat) than the Shimano ring it replaced. In the middle ring the chain would snag the shifting pins in the smallest cog. I didn't like the ring at all.
It doesn't answer you question, but I'm avoiding Middleburn rings from now on.