Problem with a 6700 Rear Derailleur pulley

[Pierre]

Hi,
Just wondering if anyone else has encountered this issue - I helped my bro-in-law clean his bike last night (he's dragging it to the UK in a fancy new bike bag) and when I re-assembled the RD pulleys, the top pulley had some real drag on it. It seems to be due to the friction between the small plastic white cylinder and its mating surface on the inside of the pulley. I lightly greased this area when I put the pulley back together but man, it's just not spinning freely. It does not feel like there is crud in there, instead it just feels like a tight fight so there is waaay more resistance on this pulley vs. the bottom one. I'm thinking that a new pulley might be in order but it still seems strange as it all looks to be in working order...

[oldpotatoe]

Originally Posted by Pierre

Hi,
Just wondering if anyone else has encountered this issue - I helped my bro-in-law clean his bike last night (he's dragging it to the UK in a fancy new bike bag) and when I re-assembled the RD pulleys, the top pulley had some real drag on it. It seems to be due to the friction between the small plastic white cylinder and its mating surface on the inside of the pulley. I lightly greased this area when I put the pulley back together but man, it's just not spinning freely. It does not feel like there is crud in there, instead it just feels like a tight fight so there is waaay more resistance on this pulley vs. the bottom one. I'm thinking that a new pulley might be in order but it still seems strange as it all looks to be in working order...

That's actually ceramic. Grease or some oil like Mobil One. Also those 2 rubber seals? Throw them away. They 'can' lead to the bolt unscrewing.

[Pierre]

Originally Posted by oldpotatoe

That's actually ceramic. Grease or some oil like Mobil One. Also those 2 rubber seals? Throw them away. They 'can' lead to the bolt unscrewing.

Thank you, OP - that's the first time I've encountered those seals on a pulley. I was tempted to do just that as they don't really seem to do much. I tried grease, so maybe I will try some Penzoil 10w30 instead...heck, I'll go all out and use Penzoil Platinum Synth! I'm wondering if I should try sanding down the cylinder very carefully as that has to be where the friction is coming from.

[oldpotatoe]

Originally Posted by Pierre

Thank you, OP - that's the first time I've encountered those seals on a pulley. I was tempted to do just that as they don't really seem to do much. I tried grease, so maybe I will try some Penzoil 10w30 instead...heck, I'll go all out and use Penzoil Platinum Synth! I'm wondering if I should try sanding down the cylinder very carefully as that has to be where the friction is coming from.

I wouldn't do that and keep them lubed or you'll take the thing apart and just find white dust. The seal gig came from a shimano outside rep with 7400 series rear ders, same pulleys(just 10t) and we had a few top pulley unscrews..he said ditch the seals. Grease will make 'em feel kinda sluggish in the hand but they will spin fine with a chain.

[benb]

While we're talking about this what tool do you need to take apart Shimano cages to clean/service the pulleys?

It looks like an allen key but as far as I can tell it's not, I've never had anything that seemed to fit well enough for me to want to try taking it apart... the ball end seems to fit in but not the regular end.

[oldpotatoe]

Originally Posted by benb

While we're talking about this what tool do you need to take apart Shimano cages to clean/service the pulleys?

It looks like an allen key but as far as I can tell it's not, I've never had anything that seemed to fit well enough for me to want to try taking it apart... the ball end seems to fit in but not the regular end.

3mm allen.