Shimano LX Front Mech adjustment.

tomsapples2000 Posts: 20
edited July 2008 in MTB workshop & tech

I recently got my bike serviced and they replaced the rear mech cable, and as I was anticipating it's stretched. Today I tuned it up and it seems to be shifting nicely, however the front mech started dragging.

My front mech is a Shimano LX with rapidfire shifters. I've read and understand the theory of how to adjust them using the High/Low screws to adjust the position of the cage in the top/bottom chainring, however they apparently have no effect. It's not marked which is high and which is low, but after quite a long time fiddling about I notice no perceptible difference by sight, feeling the cage while turning the screws, nor in actual shifting. I ended up taking the cable out and screwing the thing royally but I managed to patch it up by just adjusting the cable tension at the allen bolt by the mech. However, it still drags.

Am I doing something wrong? Is my mech broken? Surely there should be some noticeable effect in my adjustment of the screws or is it ridiculously subtle?


  • nicklouse
    nicklouse Posts: 50,675
    you need to add tension on the cable. at the shifter end.

    Have a read of the info on parktools.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • 3wheeler
    3wheeler Posts: 110
    You set the hi and lo screws first. These were probably ok already because the cable stretching will not affect these. What you need to adjust is the cable tension, if you don't have a barrel adjuster on the derailer you should have one on the shifter.