Bicycle Mechanics - high limit on front derailleur won't budge!

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randalll
08-05-09, 03:12 PM
im new to bike maintenance and tried adjusting the high-low limits on my front derailleur

http://www.youtube.com/watch?v=ngm6dr-1na0

this was a really useful video, take a look if you want to do your front derailleur.

i followed everything the guy on the video did.. we even have the same bike! (Kona Cinder Cone 08) but when i tried to adjust the high limit the derailleur didn't move. i was turning the screw that deals with the big cog.. and the derailleur is supposed to shift over steadily, but mine just won't move.


i was in the right gear, and i had adjusted the cable beforehand, so i dont think there's a problem there.

anyone know what might be stopping it?


thanks

randall


bikeman715
08-05-09, 03:22 PM
try shifting ? you need to move the shifter to move the dérailleur & chain onto the big chainring.just turning the limits will not made this happen on it own.

randalll
08-05-09, 03:32 PM
no its not a problem getting the chain onto the big cog, but when it's on, it rubs against the derailleur, i think i need to move the derailleur out, away from the bike.


when you adjust the front derailleur does it just change it's position in relation to the the bike? or does it also change how much the derailleur moves when you change the gears? like.. how many millimetres it shifts each time.


shelbyfv
08-05-09, 03:46 PM
Shift out of the big ring, then adjust the screw counter clockwise. Shift back onto big ring. If this does not move the cage out, pull on the cable. If pulling the cable moves the cage, you may need more cable tension. The limit screw does not change the amount of cable pull per click.

Panthers007
08-05-09, 04:06 PM
Without looking at your utube offering - I've seen some of those that were so vague or wrong they were laughable - I'll give you the cure-all for FD - front-derailleur - troubles. Here's the Cut & Paste job:


Take the cable off the FD. Now install it from scratch as per Park Tool Repair:

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

And BicycleTutor:

http://bicycletutor.com/adjust-front-derailer/

When you have it properly trimmed and are ready for the cable - a new one wouldn't hurt - you want to pull the cable taut - not too tight, taut. Then apply 48 to 60 inch-pounds to the pinch-bolt. Then put it through it's paces.

It's always easier and faster to install a FD from square-one, than it is to make adjustments with it already attached. This tends to fix one thing - while throwing another out of kilter. Start fresh. You'll get it.

Adding a barrel-adjuster can solve many problems with the cable coming loose - or being too tight.

randalll
08-05-09, 04:14 PM
thanks for the replies guys, big help
:)

turbo2L
08-05-09, 04:22 PM
Sounds like a problem with cable tension. Loosen any barrel adjusters all the way, switch to the smallest cog, un-fasten the cable retention screw, pull as tight as possible, re-tighten, then tighten the barrel adjuster till it barely starts to move the derailleur. After that, the derailleur should have the gumption to push the chain too far up and chuck it off the biggest cog. At that point, you can adjust the limit back so it doesn't want to chuck the chain off.