Twisted shimano pulley cage

[peted76]

Hi, looking for a bit of advice, again..
My 9070 rear derailleur is according to my LBS apparently a bit twisted. The mchanic there thinks it's the pulley cage. I brought it second hand and it's always been a bit iffy shifting.
I don't want to fork out for a 9070 rear derailleur, as they are mega pricey. So I'm looking at a new pulley cage.. question is the official shimano cages are also ridiculously priced (£159!), so should I buy aftermarket? Should I be looking at one of millions of oversized pulley offerings out there? It looks a bit of a minefield.
Anyone else have a twisted cage? What did you do?

[pdlpsher1]

Well, did your shop take the cage apart to see which part is damaged? It's super easy and it takes less than 2 min. with the bike on the bike stand. Or you could do it yourself.

I recently had an issue where the bolt holding the cage (on a 9070) to the derailleur body was way too tight from the factory, thus causing binding of the cage plate. I fixed the problem myself and all is good now.

Good luck.

[peted76]

No they didn't.. I'll have a look tonight see if I can see what's what - thanks for that.

[pdlpsher1]

While you are at it also check the derailleur hanger alignment. I bought a tool recently and it's a good investment whether you have just one bike or ten bikes.

[ms6073]

Anyone else have a twisted cage?

My experience has been that with the cage being of carbon composite construction, you are more likely to snap/crack cage on the 9000-series rear derailleur, therefore I would suspect derailleur hanger alignment. A quick check would be to observe the spacing between the cage and the metal pin just above the lower pulley, as it should be very close tolerance. Another would be to remove the pulleys from the cage and note whether the mounting bolt holes remain aligned, or become offset as a result of a twist in the cage.

[peted76]

Just an update on this, took it apart and couldn't identify what was buggered so took it to my LBS for a second time with a request for a more detailed look, they simply bent whatever it was back and it's now running straight as a die, praise be to the local bike shop!

Thank you for the advice.