Saw this on RealClassic's messageboard, posted by a MarkB who kindly gave permission for me to share it.
Mark's story that accompanies the pic is as follows:
"July 1980, the day before the Borg / McEnroe Wimbledon final, and I was 19. I was hitching down the A1 to my flat in London before going away to Jersey for a summer job in an architect's office.
I was standing at the Burghley roundabout near Stamford when this guy pulled up on an old rigid/tele BSA with a hand gear-change. The seat was a flattened Castrol tin and there was no pillion pad or passenger footrests.
Jock (for that was his name) rather gruffly offered me a lift and countered all my objections (no pillion seat, nowhere to put my travelling bag, no crash helmet etc). He proudly produced a bone-dome that was dangling from the saddle, and I ran out of excuses.
I jumped on behind him and balanced on the rear mudguard, with my bag resting over the petrol tank and handlebars, and we set off on a slow and uncomfortable ride to London. After about 15 miles we pulled in to the Little Chef past Peterborough and he suggested I might buy him a fried-egg sandwich, which I did. It must have been some time since he'd eaten.
During mouthfuls he told me that his name was Jock and he was a member of the Road Rats, a sort of itinerant group of riders who met up on the road whenever they came across each other. He basically just rode round the country, making do and accepting the hospitality of others - a bit like a godless mendicant monk, I suppose. He was protected by a thin layer of grease and his clothes shone like graphite from the ingrained oil.
Outside, by the BSA, I was thinking what a shame it was that I didn't dare ask if I could take a photo of him, when he said 'shame you haven't got a camera.' I triumphantly whipped my Pentax out of my bag and he obligingly posed for the photo. (I had no idea that the AA sign was there).
Back on the road, he let me buy him a tank-ful of petrol, pointing out that the bike would run just as well on paraffin, and then we stopped at a pub in Barnet, where I was able to show my gratitude by buying him a pint of lager before finding a bus to Finsbury Park, while he got stuck into chatting up a couple of attractive young ladies.
We both benefited from the journey: he got food and petrol and I got to London with a real feeling of achievement. And a great photograph.
