oh - one area I will pass on what a mate of mine is heavily experienced in -
is with bikes and knees
my friend is what one can only be described as a bike expert - he's rode across America several times, done a heap of endurance riding, he's had bike businesses and is a bike builder and engineer.
he's also a big guy and with lots of weight.
When I had my little tiff with roller blades - which put a knee injury on top of a knee injury - he told me several things - because he's really big into knee protection - if you lose the knees - it's not easy.
My doctor here in Fr (who has some sort of fetish for my calves) - she said the same thing.
No climbing - keep it flat, keep the load down from the higher gears.
Don't stay in too high a gear - if you have dodgy knees - temporary or permanent - come down in the gears early. You may well exhaust yourself somewhat - but, the stress on the knees isn't anywhere near as great.
My knee now seems to have fully recovered - so, I'm up for whatever my Komoot girl in my ear wants to play - MTB mode - which, in her language means - UP, down and dirty.
But, when injured or if permanently dodgy ------- then, no MTB mode.
