I've recently replaced a 48/34 compact front chainset with a 50/34. This also entailed an ISIS to GXP bottom bracket swap. I was advised also to lengthen the cables (I have a high-rise stem) which i did.
All seemed to go well until i tried to index the gears. I cannot get onto the lowest (biggest) cog on the cassette when i'm on the large chainwheel. That's not exactly true - it will do it very occasionally on its own, or if i force it in by pushing the rear derailleur to 'help'. I've fiddled with the L screw B screw and adjusted anything i can think of, but it just doesn't want to know. The rear mech looks fine and i didn't have a problem with the derailleur before the changes.
Can anyone work out what's going wrong here, please?
Thanks.
All seemed to go well until i tried to index the gears. I cannot get onto the lowest (biggest) cog on the cassette when i'm on the large chainwheel. That's not exactly true - it will do it very occasionally on its own, or if i force it in by pushing the rear derailleur to 'help'. I've fiddled with the L screw B screw and adjusted anything i can think of, but it just doesn't want to know. The rear mech looks fine and i didn't have a problem with the derailleur before the changes.
Can anyone work out what's going wrong here, please?
Thanks.