Bicycle Mechanics - Front deraileur cage width

I'm having troubles with adjusting the front deraileur shifting between the 3 chainrings. I have Alivio front deraileur while the rest of the drive train is SLX.

My thinking is that the Alivio front deraileur cage may be too wide to deal with a 9 speed chain effectively. I cannot seem to find cage dimensions anywhere to make a comparison.

Can anyone help?

Thanks,
Chris

Alivio has *only* just recently been introduced as 9 speed, for 2011. So yes, your derailleur highly likely isn't 9 speed cage width. Go buy the matching front derailleur for your drivetrain.

What exactly is the problem? Don't tell us your conclusions, but describe the nature of the problem. Trim, not enough travel, too much travel, doesn't shift from which to which, etc.?

Since we can't see your bike, the better you describe the issue the more likely someone can give you specific advice to deal with it.

Thanks operator, just wasn't sure if there was 8/9/10 sizes for the FD cage.

FBinNY, I can't seem to adjust the deraileur to move the chain onto all 3 chainrings, the smallest or biggest always misses out, but only just, it makes the noise like it's about to, and sometimes does. It's like there isn't enough travel, If I adjust the cable to allow an easy change between 2 gears only, the chain falls off when shifting far to easy. So if I have set it up to ony shift to the small and medium ring, the chain falls off to the left, and vice versa. It doen't fall aff that often, but still way more than it should.

I never had this problem until I made the switch from 8 to 9 speed with everything except the FD.

What exactly is the problem? Don't tell us your conclusions, but describe the nature of the problem. Trim, not enough travel, too much travel, doesn't shift from which to which, etc.?

Since we can't see your bike, the better you describe the issue the more likely someone can give you specific advice to deal with it.

Yeah, let's try and make an incompatible derailleur work like one that is.

Chris, Make sure there is no extra slack in the FD's cable when on the inner chain ring and/or try the B anchoring position on the FD. Just a couple of things to check before throwing down some hard earned cash.

Brad

PS I measured an Ultegra 9S FD cage width at ~8 mm and I've used an 8S Ultegra FD with a 9s D-A... apples to oranges possibly.

Thanks operator, just wasn't sure if there was 8/9/10 sizes for the FD cage.

FBinNY, I can't seem to adjust the deraileur to move the chain onto all 3 chainrings, the smallest or biggest always misses out, but only just, it makes the noise like it's about to, and sometimes does. It's like there isn't enough travel, If I adjust the cable to allow an easy change between 2 gears only, the chain falls off when shifting far to easy. So if I have set it up to ony shift to the small and medium ring, the chain falls off to the left, and vice versa. It doen't fall aff that often, but still way more than it should.

I never had this problem until I made the switch from 8 to 9 speed with everything except the FD.
What you describe is precisely the symptom of a derailleur that is not mounted properly. It needs to be as close to the sprockets as you can get it short of rubbing.

Don in Austin

Follow this Park Tool guide to Front Derailleur adjustments (http://www.parktool.com/blog/repair-help/front-derailleur-adjustments).

The "not enough travel" statement seems to indicate either limit-screws, too-high mounting, rotation or cable-tension as an issue.

BTW, my car-manufacturer recommends Mobil-1 for the engine. That does not mean that all other oils are incompatible with the car.

Yes, go to the www.parktool.com site and find the instructions for setting up and adjusting a front derailleur. Perform all of the steps precisely and in proper sequence leaving nothing out.

It sounds like to me that you may not have had the shifter in the bottom position when the cable was attached to the derailleur, and/or there may have been slack in the cable.

Thanks to everyone for suggestions, I got it working perfect now. The derailleur was mounted right, the cable was a just a little slack when at the inner chainring, tigtening it did help a little. The cable wasn't always sitting in the correct position (in a small recess) when on the smallest ring. I had to pull the cable as far as I could towards the cable fixing bolt to get it constantly sit back in the recess.

I've attached a photo to better illustrate. The red marking is where the cable is supposed to sit, and circled where the cable can still move closer to the bolt before tightening. In this photo the cable was taut and FD was at the small chainring.

Perhaps the FD is a bit out of shape from a branch becoming between it and the chainring several times, something to keep an eye on and I'll report back if anything changes.

I never had this problem until I made the switch from 8 to 9 speed

:50: some times an 'up grade' is not an improvement. :popcorn: