Front Derailleur Adjustment Trouble.


Aug 27, 2005
I spent my entire Saturday afternoon getting my butt kicked by my Mountain Bike. I have a Trek 4300 that i replaced the BB, Crankset, chain and cassette on.

Everything was fairly routine except I can't get my front derailleur to adjust correctly. I simply can't get enough cable tension to get the derailleur to push all the way out on the high limit screw and give the needed clearance between the chain and the outer derailleur cage.

My limit screws are fine. I have tried everything i know, yet still can't get it. Why won't the derailleur go out and hit the High limit screw?

I did a bit of research and think there may be one issue. I replaced my old 42/34/24 crankset with a Deore 44/32/22. I have the stock C050 front derailleur. I think i read that it will only handle a 32 and maximum difference of 18. The new deore crankset has a 44 with a difference of 22.

Is this my problem? I called a bike shop and they told me it still ought to work fine, but I can't make it work. Any help would be greatly appreciated. I had a long day. I got sunburn, bloody fingers and very tired. I still don't have the bike done. :nuts:


Turbo Monkey
Jan 19, 2005
North Carolina
calm down.

now, you need to check a few things.

1.) derailleur alignment. It should be 2-3 millimeters above the outer chainring. It also should be parallel with the chainrings.

2.) screw adjustments. Since you replaced the BB and crankset, the adjustments are probably off some. Set the screw adjustment for the small chainring BEFORE hooking up the cable.

3.) cable tension. This is probably the issue. Clamp the cable and shift into the middle chainring and the highest(1st)gear in the back. The inner plate on the front der. should be as close to the chain as possible without touching it. Adjust as needed to acheive this.

It should work now.


makes avatars better
Dec 25, 2003
Six Shooter Junction
Do you have the correct BB for the cranks?

Shimano specs between 47.5 to 50mm from center of seatstay to middle ring.

sheldon brown said:
Shimano spec, measured to the middle ring.
47.5 preferred, but for frames with oversized seat tubes, the longer dimension may be needed, because the fat tube places the derailer mechanism farther to the right.