went for a ride sunday, (still waiting for the new mech from the states) and all seemed fine except....
the chain would keep jumping off / overshooting the inside of the granny ring.
so I measured the ring spacing as best I could and it looks to me like the Granny sits closer to the middle ring than the middle ring sits to the big ring
so i packed it out with some 1mm washers and it seems fine now.
I'm a bit bemused by this latest glitch as they are middleburn rings on a middleburn spider. Big to middle seems fine in both directions but small to middle is a bit hesitant going up, and overshoots going down (without washers).
I've had to set the lower limit quite wide or it just wont shift to the granny ring at all, (I'm wondering if the mech cage is slightly bent, hence the new mech) but watching the chain come off the middle ring it would always miss the teeth of the granny ring as it can't bend that tight. (Its IG70).
Any suggestions/what am I missing?