Quote Originally Posted by sadieme View Post
Not sure whats wrong, but the chain wont move to the outer (largest) chainring. It just goes from the small one to the middle one. Sometimes it 'rattles' when on the middle one. Not sure if thats because its trying to get settled in, or what. I dont know the terminology but the piece that seems to be 'moving' the chain maybe isnt allowing it to move as far towards the outside as it should? Although it is moving to the outside. But when it 'rattles' it appears to be because the chain is hitting that piece when its on the middle ring.

Thought and suggestions appreciated.

Does that make sense?

sorry for the ramble.
The chain is rubbing on your front derailleur mechanism. On my old bike when I shifted using the left hand shifter for the front derailleur I had to push the shifter one and a half times to have it shift up to the next highest gear. Going down, I only had to click the shifter once. So, depending on your type of shifting mechanism, that may be the problem.

Otherwise, you might have to have your front derailleur adjusted.

Another issue is that it is harder to shift up the front derailleur than other shifting you will do. You are effectively moving up several gears. You can't push the pedals hard when shifting on the front. Just easily pedal as you shift.