Have you tried checking if the limit screws are set right?
jkakua on
Does it rub all the time or only in the lower gears on the rear cassette? As the chain moves up the cassette (towards the spokes) the chain line moves towards the frame on the front chainring. Indexed shifters don’t allow for fine adjustment of the front derailleur so you can get chain rub in lower gears while in the large chainring. If you have indexed shifters the front derailleur has only 2 indexed positions being in the large chainring or the small chainring. So an 9 speed cassette (for example) paired with a 2x crank gives you 18 speeds total, but will get chain rub after maybe the 5th or 6th gear. Same will happen in the small chainring as you work into the higher gears.
I’m not sure if that’s the situation you have or if your front derailleur needs adjustment. We need to better define the problem.
2 Comments
Have you tried checking if the limit screws are set right?
Does it rub all the time or only in the lower gears on the rear cassette? As the chain moves up the cassette (towards the spokes) the chain line moves towards the frame on the front chainring. Indexed shifters don’t allow for fine adjustment of the front derailleur so you can get chain rub in lower gears while in the large chainring. If you have indexed shifters the front derailleur has only 2 indexed positions being in the large chainring or the small chainring. So an 9 speed cassette (for example) paired with a 2x crank gives you 18 speeds total, but will get chain rub after maybe the 5th or 6th gear. Same will happen in the small chainring as you work into the higher gears.
I’m not sure if that’s the situation you have or if your front derailleur needs adjustment. We need to better define the problem.