Bicycle Mechanics - Big derailleur problems.

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View Full Version : Big derailleur problems.


Cretheus
08-25-07, 01:04 PM
I purchased a bike a few weeks ago now and have had nothing but bother from the front deralleur. Im using grip shifts.

At first it refused to change onto the larger sprog, this was fixed by adjusting the position on the chassis. It then refused to change down from large to small (a simple cable issue.)

I have ended up purchasing a new cable and installing it. Ive set the chain onto the smallest sprog, taken all slack out of the cable and made it tight. This is now leaving me with the inability to change into the higher sprogs due to the derailleur not moving, it feels too tight.

Any ideas for how to fix this?


nashcommguy
08-25-07, 09:34 PM
Go to www.sheldonbrown.com. r-click on 'articles by' r-click on 'repair tips' scroll down to 'derailer adjustment'. R-click on 'front'. Not trying to be a wiseguy. It's all pretty much in this series of articles. If you still have probs post back. Someone will have had the same exact issue.

Trekbikedude
08-25-07, 10:29 PM
you need to back out the high limit screw.

for another repair site, I'd suggest park tools site.


Retro Grouch
08-26-07, 05:31 AM
If it ever worked I doubt you need to adjust the limit screw. Once correctly set limit screws seldom need readjustment.

I'm more inclined to think that you may not have installed the cable correctly in the Grip Shifter. Some of those can be kind of tricky. My advice is to disconnect the cable from the derailleur, hold onto it with one hand, and cycle the shifter to see if you're getting smooth cable pull.

operator
08-26-07, 07:45 AM
I purchased a bike a few weeks ago now and have had nothing but bother from the front deralleur. Im using grip shifts.

At first it refused to change onto the larger sprog, this was fixed by adjusting the position on the chassis. It then refused to change down from large to small (a simple cable issue.)

I have ended up purchasing a new cable and installing it. Ive set the chain onto the smallest sprog, taken all slack out of the cable and made it tight. This is now leaving me with the inability to change into the higher sprogs due to the derailleur not moving, it feels too tight.

Any ideas for how to fix this?

http://www.parktool.com/repair/readhowto.asp?id=75

Read that, and come back if you have any questions. There really is no point taking any of the suggestions above (not knocking the posters) before we know you have a solid base to work off of.

cny-bikeman
08-26-07, 11:15 AM
The replies that suggested the Park or Sheldon instructions are correct. The front derailleur is far more complicated that limit screw adjustments. You must have the correct derailleur for your chainwheel combo (double/triple, narrow/wide range) at the correct height over the chainrings, and at the correct alignment/rotation. Even then sometimes tweaking of rotation is needed, and occasionally careful realignment of the front derailleur nose. Once that is all correct the limit screws come into play.

ang1sgt
08-26-07, 12:00 PM
I purchased a bike a few weeks ago now and have had nothing but bother from the front deralleur. Im using grip shifts.

The SIMPLE thing to do is take it back to the LBS that you bought it from if that is the case. If you have a defective part, they can warranty it, or if it is a simple adjustment, they will take care of it.

If you bought it used or from a Wally World Store you might be on your own so either the PARK TOOL Site or Sheldons as previously stated will help you.

DMF
08-26-07, 01:16 PM
you need to back out the high limit screw.

Unlikely. New bike -> cable stretch.


And what's with the MODERATOR tag? Who are you trying to fool?