Cheers guys.
Fitness I’m not overly bothered about, I’d say I’m relatively fit and capable of pushing myself if needed.
I enjoy riding ss more than the gears anyway so that’s half the battle.
If push comes to it I can always see about having an alfine rear wheel built up, although the ‘dinglespeed’ sounds interesting, obviously same chain, but are you confined to certain gears so as to maintain tension or do you need a tensioner? I’m running an ss only frame (io) so can’t add a tensioner afaik.