Toward the end of January 2023, my son and I drove to a shop on a cobbled side street in north-west London to buy new bikes. His was for his 13th birthday; the reason for mine was harder to explain. I had just gone through chemo, and one of the things I used to distract myself with on the long days between sessions was looking up Bromptons. That’s what I promised myself at the end of the round, partly because I wanted to get in shape after a hard year: six months of gradual decline as…

