Peter said:I bought a Trek a few months ago, and until recently it hasn't had an
awful lot of use. I've got a few hundred miles on it, and I need to
spend a bit of time doing a bit of an overhaul - adjusting brakes and
checking bolts and so on. This I can cope with, and have no problems
with.
Where I am going to struggle is the rear mech - it's slow to shift /
sticking when I go to change gear. How do I adjust the gear cable so
I'm back to smooth shifting? (other than taking it to my lbs and
getting them to do it)
Assuming its just out of line, the rech mech is easy to correct, but the
first time takes a bit of time getting used to what adjustment does what.
With a new bike what you may be experiencing is cable stretch.. what
will help is to leave the bike in a high gear (ie the cable is slack)
when not in use.
The way I find easist to set up the rear mech is;
1) change gear to the smallest cog
2) completely loosen the cable
3) adjust the H-limit screw so the guide is just to the right (viewed
from the back) of the smallest cog.
4) pull the cable so its taught and tighten the cable (the guide is
still in line with the smallest cog)
5) change to the lowest gear (bigest cog)
6) adjust the L-limit screw so the guide is inline with the biggest cog.
7) do a test ride
8) if you change down a gear and it doesn't move to the bigger cog, turn
the adjustment anti-clockwise (ie extends the path of the cable, so
makes it pull more towards the lower gear)
9) if you change up a gear and it doesn't move to the smaller cog, turn
the adjustment clockwise (ie reuces the path of the cable, so makes it
pull less towards the higher gear)
Once set up, the H-limit and L-limit screws rarely need adjusting... and
once the new cable has streched, you can normally get away with just
steps 7 to 9.
That's how I do it, but I'll be interested to hear what the more
experience regulars here do.
Regards
Mark
