My girlfriends titus motolite is throwing the chain into the bottom bracket every so often. The low limit screw is turned clockwise as much as possible, which I think should limit how far inwards the mech travels inwards, but it is still way too near the frame. The alignment looks ok. Any thoughts on how to fix it? It seems that the low adjustment is broken but havent come across this before. Please help before I order a new one.
you should be able to limit the chain to the middle ring with the low limit screw. can you see the bit of the mech that is touching the end of the screw?
havent really looked too closely. I thought turning the low adjustment screw in as tight as possible should have limited it. Just doesnt seem to working.
manually pull the mech across, and tighten the screw further?
Assuming you're fiddling with the right screw (and I've got them wrong) could you get a longer screw that would fit? A bit of extra cable tension might help too but if you just can't get it sorted something like an N-Gear Jump Stop or Deda Dog Fang might stop the chain dropping.