No huge cycling event. But here is a list of the UK national records for the ten mile time trial for veteran cyclists - "veteran", here, being 40 years old and up. I think you'll find it illuminating. Note that the 70 year-old record holder was about 17% slower than the 40 year-old.

What it doesn't tell you, of course, is how many are still competing in each age-group. Illness and injury will give rise to an attrition rate , so the further one goes up the age range the more likely it is that the guys who used to be the fastest are no longer in the field. Still the fact that Mr Brownhill was going under 30 minutes for the ten miles aged 91 is quite impressive, I think.

The 25 mile TT records are even more startling.