You might find it interesting reading up on Arthur Metcalf and others that competed in the BBAR(British Best All Rounder).

Metcalfs achievements in the BBAR in 1966;

In 1966 he won the national amateur road race championship and, as an afterthought, the BBAR with a record average speed of 24.797 mph. The BBAR aggregated speeds of riders over 50 miles, 100 miles and 12 hours and specialist time-triallists usually devote their whole season to it. Metcalfe won in three straight rides, almost as an afterthought. "I remember thinking I needed a change. I'd ridden a few time trials in the past and so I thought I'd have another go," he said.[