Front Mech Issue

[RecordAceFromNew]

Ok.. so according to the video - just before 2mins 30 if it won't shift down then I have too much cable tension, and a loosening of the barrel adjuster should sort it out?
I'll obviously double check the positioning of the mount though too.

While anything is possible (from Halfrauds ) it is common for cable tension to reduce after replacement/adjustment, not increase. PpPete's cable friction diagnostic sounds more plausible to me.

Either way it might be easy to check. If you shift onto the small front now is it pushing the chain onto the small? If not reliably and when not are you able to use your finger to help push the front mech further inboard, if you can cable stickiness is the most likely cause. If you can't then the L limit screw is likely incorrectly set* (assuming nothing is bent/broken/loose - none obvious from the photos) - you should see a 1mm gap between the inside of the inner cage and the chain when you are on small front large back.

* you might have been able to shift onto the small ring previously because you were on larger cogs at the back.