An indexing question

phreak

Hi all,

I cleaned my bike yesterday and had a slight problem with shifting on a ride today, so I've been playing around with the barrel adjustor to try and make it a bit smoother and fear I've truly bolloxed it up.

The chain is in the middle of the rear cog, yet the shifter to move it down won't budge (as though it's in the bottom gear). I haven't touched the limit screws at all, and the gears seem to shift ok by pulling on the cable itself.

I'm sure it's a simple thing but I'm going round in circles here. Any ideas what I've done to mess things up?

cswitch

Wind in the barrel adjuster all the way in so less tension on the cable (probably best to use whichever adjuster you was using before...rear mech or on the downtube...so you don't get too far away from where it was working okay though generally rear mech is the easiest for adjustments).

Put it into big ring / small sprocket. Next try to shift up to the next cog - it quite possibly won't or will be noisy as insufficient cable tension. If so keep flicking gear down and back up whilst adding a quarter turn of tension . When it eventually starts to change up then start going up and down the cassette. If its still sluggish going up the cassette keep adding a bit of tension i.e. quarter turn until moving up the cassette. Be cautious of applying too much cable tension as it may change up great but will struggle to drop down the lower part of the cassette making the down changes quite clunky or not at all.

If its noisy around the middle of the cassette you may have too much or too little tension which can be remedied by a quarter turn or so either way

One helpful thing to remember - if chain struggles to move down the cassette then typically too much tension in the cable and if struggling to go up the cassette then not enough.

phreak

Thanks for the response. It just baffled me why the shifter wouldn't move when there were still plenty of cogs to move into. Would an ill-adjusted barrel do that?

doug5_10

As above, if I'm making a balls up of indexing I just wind barrel adjuster all the way back in and start again.

I use exactly same method as cswitch
-H and L limits set
-start from zero tension a quarter turn at a time on bottom 2 cogs until shifting is smooth
-then check up the rest of the cassette, even tiny little adjustments either way can make it sound and shift sweeter.

doug5_10

Sounds like you had far too much tension if it wouldn't shift down the cassette (i.e. into a higher gear/smaller sprocket)

Check your shifters just in case, take all the tension out and check the number of clicks (10 speed will have 9, 9 speed has 8 etc.) Would also check cable isn't frayed anywhere (particularly inside the shifter) and lube cables thoroughly.

phreak

Yes, it turned out that the cable inside the shifter had gone. Trip to the bike shop required in the morning.