I watched a programme on McQueen, on that Bud Elkins said McQueen did want to do it & trained for it but wasn't sure he could make it so Bud did it himself, I don't remember any mention of the insurance etc & McQueen wouldn't have taken any notice anyway, they never wanted him to race or do the isdt but he did it anyway
The new bike has around 65hp & a big lump of torque the old speed twin had maybe 35hp if you were lucky & about as much torque as your average rice pudding, the new bike has good long travel suspension both ends that will no doubt be set up professionally or even changed for the jump Bud Elkins had a road bike with longer stiffer rear springs & more oil in the forks + faith in his ability, a huge bucket full of skill & no fear.
Sorry but I see no comparison in what was achieved back then & what is being attempted now !
I think I will take the info from a museum rather than a telly program that was ( if memory serves ) a homage to McQueen.. which contained a fare bit of stuff from his son that was later refuted by others
The bike they used was far from standard ( currently owned by Dick Shepherd as part of an extensive Trumpet collection ) and it was a TR6
Too late to get the exact spec it was then in, but it is speculated to have had around the 50 to 55 BHP mark which would be very believable given the factory spec
The TR6 weighed in at 365 lbs
The new version has 65bhp and weighs a porky 454 lbs !
I therefore think they are quite comparable in the performance stakes.. But I would add the older version would have been, in my opinion, far more nimble