Anyone know if I change from an SLX 9 speed rear mech to a SRAM X9 rear mech (both long cage) will I need to change chain length at all. i.e are the angles etc the same ? I have a worn out SLX rear mech and pretty tatty shifters, but I do have a nearly new X9 rear mech and shifters I can swap over to, so just wondering if its a possibility without having to faff with chain length Thanks.

The chain will be Ok length wise and as long as you put on a Sram shifter you’ll be fine