Out on a club ride tonight and at one point my left shifter just wouldn’t shift up to the big ring. I assumed it was a cable issue and it was a hilly ride so thought I’d just carry on in the small ring and check it out when I got home.

After a while i put a bit more tension on (in line barrel adjuster) whilst dragging up a climb and it seemed to be OK. However later on the shifter wouldn’t spring back after a shift and needed an extra push. It then seemed to sort itself out.

Had a few pints post ride (club is at a craft ale bar) and walking home the shifter wouldn’t return normally.

Is this a common issue, I guess I’m thinking:
1) something stuck in the shifter
2) cable issue
3) shifter borked

Hoping for 1 or 2 really.

I’ve had the gear cable coil up one time inside the shifter in a way that the cable wouldn’t be released. Try a new gear cable inner. Also look for stones or some other obstruction within the mech.

Could also be something loose, maybe check all bolts/screws/nuts are tight first.

Frayed cable? I had pretty much this and only found the bit of Fayed inner when they were pushed out by new cable going in.

I had an issue where the low-friction fitting on the bottom bracket (the one that guides cables around the frame and the up between the rear wheel and the seat tube for the front deraileur) had worn.

What was happening was the cable was cutting into the carbon frame and had created a slot in which it would stick – it usually meant I could change down easily but when it came to changing up it was extremely stiff, but occasionally the cable would stick in both directions.

Cable frayed, probably. The tight bends inside modern Shimano shifters destroy cables. Get it changed before it breaks and leaves a load of shrapnel inside the shifter.

Will get the cable sorted ASAP in the first instance. Cheers.

I have seen 2 r800 like this and 1 r7000, the shifter goes really crunchy and locks,then will sometime move freely and shift well,comes and goes,I warrantied one and replace others as out of warranty,I stripped them,re greased etc,worked ok for a bit then same problen