cannot shift down up hill

Caher said:

Hi all,
when i try to shift gear whilst travelling up hill nothing happens. I can hear it trying and the indexing is properly set up but under pressure it refuses to shift! I have shimano deore front mech with similair standard chain rings.

Front derailleurs are not designed to shift while under load - the tension on the chain is too much for the light spring in the derailleur to overcome. Ease up on the pedals for a revolution and it should shift fine. This may require planning ahead to shift before you *really* need to.

Hmmm...I think this explains why I can't shift very smoothly on my new rim-drive trainer. There is so much resistance on it and I was wondering why my front gears weren't shifting very well - makes sense. When I adjusted the resistance lower, it shifted a lot better, but still not as smooth as when on the road. Interesting!

I must have been spoilt by my other bike which is XT/XTR equipped. It will always shift under load. Predicting up coming hill can be difficult!
Thanks
Caher