Chainring down shift
 

Hi,

Is having trouble shifting down a chain ring indicative of it being worn out? I ask as I thought that worn teeth would make the chain more likely to move not less.

Thanks.

Chainring wear has little to do with downshift performance. The FD typically moves in via the return spring, so slow downshifting might be the result of cable friction, or poor FD adjustment. It might also be the result of your not easing up on the pedals to allow the shift.

Shifting requires the chain to lift over the tops of the teeth. High chain tension from pedal load, resists that by pulling the chain down onto each tooth as it engages. So the very first step in dealing with sluggish FD shifting is to check it at zero load. If it's still sluggish, then cables or adjustment.

Worn chain rings, probably not. I would start by releasing the cable tension from the front derailleur and manually moving the derailler to make sure it doesn't have any binding. Next, grab onto the cable and pull it to create tension and then shift it to see if there is binding in the shifter. If there's binding in the derailleur, you can take it off and soak it in something like wd-40. If there's binding in the shifter, you can do the same or you can spray a degreaser into it if it is an STI shifter. If there is no binding, I would check the position of the front derailleur and/or replace the cable and housing.

On the front, you can derail chains with your heel. though FD's are more convenient..

You can also brake with your toes!:D

Thanks.

I'd tried changing the cable, so I'll give the derailleur itself a closer look.