Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Ultegra R8020 front shifter sticking under tension

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Ultegra R8020 front shifter sticking under tension

Old 05-05-20, 04:24 PM
  #1  
waterrockets 
Making a kilometer blurry
Thread Starter
 
waterrockets's Avatar
 
Join Date: May 2006
Location: Austin (near TX)
Posts: 26,170

Bikes: rkwaki's porn collection

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 37 Post(s)
Liked 91 Times in 38 Posts
Ultegra R8020 front shifter sticking under tension

Hey, I bought a used ebay bike with Ultegra R8000 disc 11-spd group. When it arrived, I noticed that the front shifter, going from from small ring to big ring was catching before moving far enough to shift. On a second try, I am able to shift it with a "snap" that feels like breaking a very thin zip tie. It doesn't seem to damage anything, and does this exactly the same every time. I noticed that the derailleur was under tensioned (cable slack in small ring).

I installed a new cable (old one looked fine coming out), went through entire Shimano process with limit screws, cable routing, cable tension, etc. It would NOT shift to the big ring -- that catch just sticks. If I under-tension it, it will shift with the catch on the first try, and success with a snap on the second try. So I'm exactly where I started, but with a new cable. Also, the shifter will move smoothly through the shift if I move the derailleur by hand (limiting the tension on the cable).

So, it appears that the shifter needs to move a certain distance before it hits tension, or it won't shift. I'm guessing there's a strand of old cable inside it or something, but I didn't see any obvious access panels I could remove to investigate, and the cable routing through the shifter is brief and doesn't appear to be near the ratchet system.

Any thoughts on working this problem, or is it time for a new shifter?

Thanks!

Last edited by waterrockets; 05-05-20 at 04:41 PM.
waterrockets is offline  
Old 05-06-20, 08:27 AM
  #2  
Buzzkill53120
Junior Member
 
Join Date: Jul 2017
Location: SE Wisconsin
Posts: 128

Bikes: Trek Domane SLR 2019, Trek Trek Madone 5.1 (2011), Trek 1400 (1991)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 47 Post(s)
Liked 73 Times in 33 Posts
Replacing the housing may help. Helped for me when I had problems with the RD. Shift mechanism in the lever may have been damaged. This can happen in a crash or if someone tried to force a shift with a jammed chain.
Buzzkill53120 is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.