Ultegra Di2 6770 Pulley Drag

Discuss light weight issues concerning road bikes & parts.
Post Reply
allenpg
Posts: 112
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!

-Pete

dha
Posts: 163
Joined: Tue Jun 12, 2012 4:40 pm

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


User avatar
trychle
Posts: 240
Joined: Thu Nov 29, 2012 12:36 pm
Location: The Netherlands
Contact:

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.

Omiar
Posts: 218
Joined: Wed Dec 14, 2011 8:20 pm

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

Teletori
Posts: 34
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.

Post Reply
  • Similar Topics
    Replies
    Views
    Last post