Thanks for the suggestions, guys. Forgot I had posted here, so only seeing this now. Apologies for not coming back to you sooner.

To answer the questions asked: I can't move downstairs or outside. I love my new flat, so moving isn't an option for now. My neighbour's and my hours of work are similar. Putting spray foam / insulation down isn't feasible. Am considering cork board / MDF or something like that. I may move the bike into my large bathroom which is over the corridor below versus people's apartments and try it there first. Bit of a pain in the arse, but might be the only sensible option.