Bicycle Mechanics - Front Derailleur not shifting into small gear

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abstractform20
09-12-09, 11:54 PM
please help me.

and my other road bike's fd wont shift to its largest gear.

this is cruel


Steev
09-13-09, 05:44 AM
More information gets more useful replies.
The first thing to check with any shifting issue is that the cable is in good condition and moving freely.
After you've checked the cable, you next check will be derailleur function and adjustment. Check this link. http://www.parktool.com/repair/readhowto.asp?id=75
If going thoroughly through those does not address your problems you may have a shifter issue.

kycycler
09-13-09, 06:13 AM
Disconnect the cable from the derailleur. Check to make sure the cable is not binding in the housing and the shifter is working. Next see if the chain goes onto the small chain ring when you pedal. If not then the low limit screw is not adjusted properly. For the rear derailleur the chain should go to the largest gear (smallest diameter). If it does not then adjust the high limit screw so the pulleys align with the gear. Next attach the cable to the derailleur and set the tension. For a more complete description see either Park Tools web site or Sheldon Browns.


DMF
09-13-09, 09:58 AM
New Posters - please READ THIS (http://www.bikeforums.net/showthread.php?t=338432)

cyccommute
09-13-09, 10:29 AM
please help me.

and my other road bike's fd wont shift to its largest gear.

this is cruel

The first thing that everyone tells someone with a derailer problem is to adjust the limit screws. This is just plain, flat wrong. Messing with the limit screws is the absolute last place to start with a derailer adjustment. That's after you've replaced cables, housing, shifters, and even wheels:rolleyes:

Assuming that the bike shifted properly in the past, the issue isn't with the limit screws. It's a cable issue. Failure to shift is almost always a cable issue. Failing to shift into a lower gear...again assuming that it shifted in the past;)...is because the cable is too tight. Have you been adjusting the cable to fix another problem? If so you've probably tightened the cable so that the derailer can't move over properly. Is the housing binding the cable? Then the cable isn't moving far enough to let the derailer move. Is the cable gunky? Or dry?

Your other derailer is having the opposite problem. It's cable is too loose. You need to tighten it so that the cable can move the derailer the proper distance.

The links that DMF provides are good resources to learn how to do it. Outside of that, go to a shop and have them show you.

Panthers007
09-13-09, 12:24 PM
My Copy & Paste.....
___________________________________________________________________________

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.

abstractform20
09-13-09, 09:26 PM
thanks. tightened the cables. now my pedals cant turn on one...

operator
09-13-09, 09:36 PM
thanks. tightened the cables. now my pedals cant turn on one...

lol.

Could you please provide better problem descriptions?

Al1943
09-13-09, 09:47 PM
thanks. tightened the cables. now my pedals cant turn on one...

Which cables did you tighten?

Panthers007
09-13-09, 10:00 PM
Use an UZI. Hope it doesn't jam...

abstractform20
09-13-09, 10:19 PM
Use an UZI. Hope it doesn't jam...

i have a boomstick...is that similar?

i tightened the fd cable because i realized it (on both bikes) was very loose.

however, no i cannot pedal on one...the wheel wont turn and it prohibits the cranks

Panthers007
09-13-09, 10:43 PM
Has your chain fallen off the chainring in between the bottom-bracket shell and the crankarm?

operator
09-13-09, 10:48 PM
i have a boomstick...is that similar?

i tightened the fd cable because i realized it (on both bikes) was very loose.

however, no i cannot pedal on one...the wheel wont turn and it prohibits the cranks

This tells us nothing.

abstractform20
09-14-09, 01:13 AM
Has your chain fallen off the chainring in between the bottom-bracket shell and the crankarm?

no. the cranks turn now, but the fd will not shift.

joejack951
09-14-09, 05:38 AM
I usually never say this, but please, do us all a favor and take your bike to a shop. Reading this thread is frustrating due to the lack of useful info in your posts.

Failing that, do some searching on front derailler issues. See how other people describe their issues and figure out if what they are describing fits your situation. Perhaps you could copy and paste someone's else problem description in this thread. What you have provided so far is worthless in helping anyone diagnose your problem.