Yep, it was a Triumph TR6.
It's an Urban Myth (and one that I was told and repeated too for a while) that it was the same bike that the Fonz used to ride. After a bit more research (and the fact that this wasn't mentioned in a book on Steve McQueen that I was reading) it turns out that the Fonz's bike was actually a TR5, although it was supplied by Bud Ekins (the stuntman who actually performed the jump in The Great Escape).
However....
Can you name anymore Hollywood stars who rode Triumphs (and which model), either in a film or in real life?
off the top of my head, l theres Pammie Anderson on a Thunderbird and Tiger in Barb'd Wire (never seen the film just the pics of her on the bike :) ) Tom Cruise in one of the Mission Impossible films on a Speed Triple, and Hugh Lawrie has/had a modern Bonneville..
for a few more (although not all up to date) look here
http://www.imcdb.org/
It was in the the David Essex film of the same name.
This will tell you but you don't have to look.
http://www.motorcyclenews.com/MCN/News/newsresults/Gene...EPI-129496