Ultegra front derailleur cable tension question

Back by popular demand, the general all-things Road forum!

Moderator: robbosmans

Post Reply
nemeseri
Posts: 794
Joined: Tue Apr 07, 2015 5:40 pm

by nemeseri

I had my LBS replace my front shifting cable 6 weeks ago. After a couple of weeks I noticed that I had some chain rubbing in higher gears like higher than 50+15. Obviously it was because some initial cable stretch, so I increased the cable tension in the trim position (following the shimano manual). This solved the issue.

What's kind of surprising is that now just after 4 weeks my cable tension is completely off again. Basically I have chain rub in every gear. I'm about to re-adjust the tension again, but I was wondering if it's normal. Thanks.

User avatar
Calnago
In Memoriam
Posts: 8612
Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

Since it sounds like you had it adjusted properly at one point, and now it's not after some use, I'd say it's either cable stretch or maybe there's some slip in the retention bolt? Not tight enough maybe? I don't know, that's the obvious place to look. Hopefully it's not your bb coming a bit loose causing the chainline to be creeping to the side a bit. What kind of cable did your LBS replace the old one with? A Shimano cable, or something else? Just wondering if whatever they replaced it with might stretch more. Think I'd try adjusting it one more time to see if you can get it to it's proper functioning state again, then just ride and see if it holds up. It can't stretch forever, one would hope. Also, how is the front derailleur attached... band clamp, brazeon, or screwed on derailleur tab? Make sure that there's no movement happening there as well.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



nemeseri
Posts: 794
Joined: Tue Apr 07, 2015 5:40 pm

by nemeseri

Calnago wrote:Since it sounds like you had it adjusted properly at one point, and now it's not after some use, I'd say it's either cable stretch or maybe there's some slip in the retention bolt? Not tight enough maybe? I don't know, that's the obvious place to look. Hopefully it's not your bb coming a bit loose causing the chainline to be creeping to the side a bit. What kind of cable did your LBS replace the old one with? A Shimano cable, or something else? Just wondering if whatever they replaced it with might stretch more. Think I'd try adjusting it one more time to see if you can get it to it's proper functioning state again, then just ride and see if it holds up. It can't stretch forever, one would hope. Also, how is the front derailleur attached... band clamp, brazeon, or screwed on derailleur tab? Make sure that there's no movement happening there as well.


Thanks! It's braze-on and they used shimano cables (afaik). I will take a look and try to adjust it again.

loudtiger
Posts: 125
Joined: Sat Apr 30, 2011 3:37 am

by loudtiger

I had a lot of trouble with installing my 5800 FD yesterday and found a trick across the hall...

I'm not running any tension adjusters and was having a hard time getting the cable tight enough. This new FD design requires more tension than you can put on the cable without the adjusters. However, you can set the cable when the derailleur is in the big ring position.

1) Disconnect FD cable
2) Turn the cranks, push the derailleur over so the chain is on the big ring
3) Use a tire lever to hold the derailleur in the big ring position. I wedged it gently between the chain and the outer cage.
4) Pull hard on the cable, and attach it to the FD at this position, when the FD arm is lowest.
5) Success

We'll see how it holds up.

User avatar
Calnago
In Memoriam
Posts: 8612
Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

Ah, I just use the lower limit screw to keep the derailleur at the position you're talking about above while I get the tension right with a 4th hand tool and tighten it down. After that, you can let the lower limit screw back to where it should be. No need for a tire lever and "wedging".
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

Canofale
Posts: 50
Joined: Sun Jan 17, 2016 7:33 pm
Location: UK North West

by Canofale

Been having the same problem, I'm running out of tension adjuster, I find after a few weeks there's not enough tension for the trim function to be effective, I'll try the above method.
2015 Caad10 Ultegra 7.1kg
2016 Giant TCR Advanced Pro 6.6kg

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



Post Reply