I have an Acera front mech and it ain't much good. It can't shift on to the largest ring and if I want to then I have to kick the chain with my foot. This isn't easy. Fortunately I don't use the large ring much. I'm after a new mech but after reading a few web sites I hear that all Shimano front mechs tend to have this problem. Is this true? Can anybody recommend the best front mech with a budget of (unless there is a particularly good one for a bit more) about £20 ($30), Shimano or not?