front derailleur problem

[rich p]

I had to remove everything from my bike to have the frame repaired so I took everything I could apart and cleaned it. Now having put it all back together, try as I might, I cannot get the change from middle to smallest ring to work properly. It will change fine on the workstand or on the flat but as soon as I hit even a shallow incline it won't. I have shunted the derailleur up and down, tailing it in and out but always the same result.
I originally had the small ring the wrong way round and hoped that would sort it. I have renewed the cable and the cable cover to no avail.
If I adjust the inner screw to force the chain off the middle it means it the chain falls off the inner ring.
It's not the end of the world but slightly frustrating.
Any ideas of what I could try?

 

[Crepello]

That the chain will shift on the workstand suggests that the mech isn't really moving inwards sufficiently. When you say "If I adjust the inner screw to force the chain off the middle it means it the chain falls off the inner ring", you mean that you have done this and that is what happens? I don't think off the mech cage as a anti chain drop device per say, so the chain won't necessarily drop off if the mech cage is moved inwards a little. I think that the chain is more likely to drop off when the mech won't shift the chain cleanly.

If all else fails you could fit anti anti chain drop device in addition to moving the mech inwards.

 

[Chrisc]

Make sure that it's as close as possible to the big ring when you fit it. Barely missing the teeth. Then if it's working on the stand it's just a case of fine tuning limit screws and cable tension. Patience and keep at it. Good luck!

 

[Moodyman]

Get rid and buy a hub gear bike.

You'll never look back.

 

[rich p]

Twice now, although a week apart, the left shifter hasn't pulled enough cable to shift from the small to inner ring and then worked properly the next time. Do you think that it could be a shifter prob or is that coincidence?