gear indexing

Nick@D

Hi,

a newbie to site & any help would be greatful

I have a road bike with a shimano (tiagra) groupset & on the front i have two chain ring's (wow), ok, concern, i find my front lever doesn't seem to index correctly or is it, going from the larger ring to the smaller at the front, i have to move the lever across with no chain movement & then repeat again with the lever to move the derallier & the front derallier snaps into smaller front ring. i believe it is set up correct but cant help thinking it should be 1 click = 1 movement is it because it should operate with three front rings.

Sorry to waffle, but it is not easy to discribe.

Cheers

Nick

Mr Plum

Hi Nick. This is normal and is kind of a 'half step' down before the full step onto the smaller chainring - if you look closely you'll see some slight movement from the front derailleur with the first 'click'; this allows the chain to cross a wider angle from the front to the rear gears - it allows you to be in a larger cog at the back whilst staying in the big chainring on the front. You get max torque whilst being in the big (53t) chainring which is why it's beneficial to be able to run a sharper angle chain-path to stay in the big chainring whilst changing down gears going up a hill for example. Not sure if I've explained it very well, but you can play around with it and get an idea of what I'm trying to explain. Anyway, rest assured that there is meant to be the additional movement, or 'click', in there.

Nick@D

thank you very much Mr Plum, that has put my mind at rest as i wasn't sure if i was causing damage to the levers, & well explained

regards

Nick