I don’t know, I quit when I was 58, my uncle raced at a higher level than I did till he was 70. I don’t think age is a big factor. Jeff Gordon also started when he was 7 or 8 years old, so maybe was just burned out. Most of the going faster in racing, whether cars or motorcycles involves learning to be smooth, smooth is fast.
It does get awful hot in a suit and helmet, I’ll give you that one! .032 aluminum between you and the headers is not a lot of insulation.
I can also relate it to shooting sports, my eyes aren’t as good, but my basics are. I shoot better competitively than when I was 20.
I have a customer in his 70’s that drag races. He tells me that he is one level below professional. He has been doing it for many years. His kids and grand kids participate in their age classes.
I like to go up to the Loudon(NH) motorcycle races every July. What I enjoy is the Friday and Saturday races when you drive right into the infield, park and walk anywhere you want. Last year my son and I got drafted into helping a pit crew. There were two guys there from a team out of NC. They took turns on the bike. They were professional races.
My son had long pants on, so he could go across the wall. I was wearing shorts, so I had to stay on the inside.
Also, on the Friday and Saturday there are many amateurs. You can tell them when they pass by because the pros are going by them like they are standing still.