Evening all. Bit confuddled as I had it in my head that 9 / 10 speed rings are pretty much interchangeable.
Just replaced my worn out chain, cassette and cranks. Chain and cassette 10 speed.
The cranks are deore 590-10. So 10 speed. It's a triple, the small ring is 26 t, marked up as 10 speed. The middle ring is 34t (no marking), the big ring is 44 t marked up as "mega 9".
Front derailleur is set fine and small / middle shifts work great. Going from middle to big is fine but when I come back down, the chain rides the middle teeth against the inside face of the outer Chainring (kind of freewheels /surfs above and eventually sometimes drops in). Checked the spacing and there is actually about a 1mm difference (greater) between middle and big ring (as opposed to small and middle) .
Actually looking at the outer chain ring it does not seem to sit flush with the face of the tabs.
Anyone else have this issue?
Without taking a mill to the back of the chain ring, I cannot see how I can reduce the spacing.
Hmmmmmmm
Here are some pics. You can see how much the chain ring sits proud of the tabs...
Also the second pic clearly shows a big difference in ring spacing...
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I had the same crankset and when I put the new rings on the chain kept slipping from the middle to the small ring - realised I had put the middle ring on the wrong way round, Is it possible you have done the same with the outer ring? (sorry I know its a basic question).
Otherwise I know my other half had to file his rings down to line up with the tabs (that was a truativ carnkset though)
No problem thanks for the reply.... I did just double check and the chain rings are definitely the right way round (the outer has a pin which lines up with the crank to stop chain getting stuck in the gap). Middle ring cannot go on the wrong way as shift ramps would be on the wrong side.
I know there would be slight differences between spacing of 9 and 10 speed chain rings but did not expect to be as much as 1-2mm or so.
The only thing I can think of maybe is that it's an early mega 9 speed Chainring. Always thought 9/10 speed rings were interchangeable but in my case it looks like not.