Gearing gone on shimano sis

[karlos_the_jackal]

My rear gears have gone on my decathlon MTB (i'm saving up for a tricross or equivalent), only just quickly checked cable because was late for a meeting and still seem tight, no derauiler issues but just doesn't click through the twist bar gears. What else do i need to check want to try and do it myself, is it worth just tightening or putting a new cable in.

 

[tandemman]

I would change your twist grip up to top gear (7, 8 or 9 depending on what you have )
turn the cranks to move the chain down the block and then check cable tension. it should have no slack in it at all in top gear, so undo cable clamping bolt on rear mech and pull cable through until it is tight, hen re-clamp.
Hold the back wheel off the ground, change down one gear on the twist shiftand adjust the barrell adjuster on th rear mech until it changes down a gear, then you should be ok

 

[fossyant]

I assume these are grip shifts (not shimano)......

Check the cable pulls through - i.e. give it a tug if you drop to the smallest sprocket (without pedalling).

If you move the mech ok by pulling the cable, then check the shifter is functioning - I'd disconnect the rear mech, and hold the gear cable near the down tube (the one that runs from the front to the bottom bracket). then twist the shifter to see if it moves.

Good chance in needs a clean out/new cables

 

[karlos_the_jackal]

cheers guys, will do the tests recommended. And yes they are grip shifts.

 

[karlos_the_jackal]

thanks for the advices, seems that just a pulling out the cable on the rear mech and some adjustments have sorted out the problems.

Unfortunately was then tweaking my v brakes which are annoying the hell out of me now!

Going in for service anyway