Ultegra Di2 6770 Pulley Drag

Discuss light weight issues concerning road bikes & parts.
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Joined: Tue May 20, 2008 5:34 am

by allenpg

Has anyone else noticed that their Shimano 6770 rear derailleur upper pulley has quite a bit of drag? Ironically, I only noticed this after 4K miles. The lower pulley spins super smooth. I guess I'm used to older Shimano rear derailleurs. Or is there an issue? Thanks!


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by dha

I have a 6770 rear mech sat next to me on my desk and the upper is certainly not as free spinning as the lower.

by Weenie

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Location: The Netherlands

by trychle

Yep. that's how it is..

The upper pulley has 'sealed' bearings, which means that they've placed two small rubber rings on each side of the pulley. These things cause looooottss of drag. And as the removal of these rubber rings will result in play on the pulley, I would suggest just to buy some aftermarket ones.

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by Omiar

A dip on chain lubricant makes it a little better, but yes, it still drags quite a lot. In terms of watts, it isn't something significant.
Scott Foil Ultegra Di2
Scott Scale 35 26"
Scott Spark LTD 29" M8000

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Joined: Thu May 27, 2010 2:36 pm

by Teletori

After a winter of cycling with grits and salt on the road my upper pulley almost did not turn, but the lower was smooth.

Turns out the upper pulley is a bushing, and only the lower is ball bearing.

Just change it out for a ball bearing pulley and it will get a lot better.

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