Have questions or want to discuss cycling? Join Now or Sign In to participate in the BikeRide community.

New: Take part in the National Bike Safety Month giveaway for a RiderBag reflective backpack


Front derailer won't extend far enough
#1
Hi ,
First post here on the forum . I have a problem with my front derailer not extending far enough . Even with the cable tightened fully the front tip of the derailer cage rubs on the chain when it is on the largest chainring . It was working before but after stripping down the bike to clean and then reassembling this problem has appeared.
The front derailer seems reluctant to go to the smallest chainring from the middle as well, needing a little push with my finger . Its as if it was clogged with dirt but is it is not.
Don't know where to go from here, (dont say lbs) any ideas anyone ?

  Reply
#2
I'm thinking maybe both your H and L limit screws are a bit too tight. They are meant to keep your chain from going to far either way. Check <a href="http://bikeride.com/adjust-front-derailer/">this video</a> at about 1:15 for tips on how to adjust them.

  Reply
#3
Hi Alex , thanks for getting back to me. I've watched the tutorials a fair few times while rebuilding the bike and i think i have the screws as right as i can get them. I have the rear derailer running sweet .
The front derailer inner guide is about 1-2 mm from the chain on the small ring , as close as i can run it without slap friction.<br />
Middle ring is ok.
Big ring is the problem. Both not being able to properly shift up to it and not being able to run it without outer rail friction. I'm thinking as I type this could possibly be a cable problem. I have a spare gear cable and I'll throw it on and see if it helps. Thanks.

  Reply
#4
It does sound like a limit screw problem. However, it could be your front derailleur is misaligned. If you removed (or bumped it) during your cleaning. In general, the outer side of the derailleur cage should be parallel to the chainrings. If it is not, it will be tough to ever get it shifting properly. Height wise, you generally want it as close to the large chainring as it will go without rubbing. (a few millimeter gap is good).
Also, check to make sure you have the cable attached on the derailleur in the right way. The clamp bolt often has a little indent or slot that the cable sits in. If you clamp the cable on the wrong side of the bolt, it slightly changes how far the derailleur moves on each shift at the lever. Check to make sure the cable is aligned in the guide that runs under the bottom bracket also. Good luck.

  Reply
#5
Thanks for your reply DaveM . It turned out to be the cable after all . I'd noticed it had lost the end cap and become frayed , then when i started adjusting it the kinks already in it came into play and it would not feed through the derailer properly. It was an oldish cable , 4 years or so. Thanks for the replies .

  Reply


Possibly Related Threads...
Thread
Author
Replies
Views
Last Post
 
4,243
06-10-2014, 01:47 AM
Last Post: 1FJEF
 
8,084
12-28-2013, 12:21 PM
Last Post: cny-man
 
6,072
06-20-2012, 03:11 PM
Last Post: DaveM
 
8,218
07-13-2011, 01:50 AM
Last Post: Joe_W

Forum Jump:

[-]
10 Latest Posts
Clicking when pedaling on bike.
Today 04:00 PM
Trouble Mounting Front Brake Calliper
Today 03:40 PM
National Bike Safety Month | RiderBag Gi...
Today 12:03 PM
CRESCENT PEPITA '72/'73
Today 09:35 AM
Vintage Road Bike Restoration HELP
Today 03:35 AM
COLNAGO NUOVO MEXICO 1986
Yesterday 05:42 PM
Tires?
Yesterday 11:29 AM
Saronni Colnago Critrium Frame set
Yesterday 04:08 AM
Help me date this Rollfast
Yesterday 03:11 AM
SmartHalo all-in-one biking accessory | ...
Yesterday 02:25 AM

[-]
Top 5 Posters This Month
no avatar 1. Jesper
21 posts
no avatar 2. CharleyFarley
21 posts
no avatar 3. Criminal
15 posts
no avatar 4. Painkiller
13 posts
no avatar 5. G_M
12 posts