xtr mech gone flacid

I've used this m900 RD daily for years but it cant keep the chain tensioned well any longer... would love to fix it though its such a cool piece of 90s mtb tech.

Does anybody know if there are replacement springs for these?

Or maybe I can swap the springs from this much snappier exage that got with a frame? Here's a conspiracy theory for ya, they look almost identical!

Any ideas appreciated!

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That is more than likely a fairly straightforward service for a mechanic who has a clue. Where's your location? I might be able to suggest a shop.

I have a clue... now!

So the springs are exactly the same. I disassembled and cleaned both. Put the xtr back together with the exage springs, now its snappy AF. Also, very cool, the xtr has two notches for the chain tension spring, so when it goes weak, you can choose the other notch.

Good to hear you got it back going again. It might have actually been fine if you'd just cleaned and regreased it but probably even better with the new spring.

Also good to know the other spring worked. Shimano tech docs actually say which parts are interchangeable between models for some older mechs, not sure about the new ones. The b-tension spring is often interchangeable.

yes i think you are right, cleaning the spring and greasing the axles might have done it, they were quite caked with rust and grime...

Now its like new, very happy about this!

A couple of times I've improved the shifting on these by finding a washer slim enough to fit behind the circlip on the back of the mounting bolt, to take the slop out of a worn upper pivot.

ah thats a good trick ill keep that in mind! on this one i had the opposite, that bolt was pretty much stuck. The axle has two grooves for o-rings to seal the axle which will need replacing if I can find some that fit...