Trying to sort out a friends bike, sorted the rear mech out and it now shifts. Having trouble with the front mech. Shimano 3x8 system if it helps, altus rear mech so assume the rest is too.
Set the high and low limits and re attached the cable. Shifts from granny to middle ok but struggles to get to largest chainring, but it does it. When shifting down though, it jumps from largest to granny in one click. I also can't seem to get the chain to stop rubbing against the mech plates at the extremes of the cassette. Tried various angles but only seems to get worse.
Can anyone shed any light on it for me?
I'm no mechanic but I generally start by winding both stop screws right out, then tension the cable until the chain will drop onto the granny (but only just). Then it should change into the middle and big rings. Finally adjust the stop screws to stop any over-shifting (and a squirt of light lube into the shifter pod). HTH.
From ancient memory of sorting front mechs, what squirrel said. Get it working off cable tension and set the limiters after that.