Cheers. I did s**t my pants a bit. More luck than skill to be honest.

I've used HD tubes on the road for 20 years and never had a problem. Certainly I can only remember having the front go down once before on the road and that was slow enough to control the pull over/stop. This time it went flat instantly.

I spoke to the fitter personally as I was interested in what had happened. Nothing sticking in the tyre/tube, no obvious wear, valve was fine. Rim tape was like new (the bike's only got 800 miles on it) and I hadn't pinched it by hitting anything (that i'm aware of).

Reckon it was a tube manufacture fault. Can't be anything else.

Falling off at 80 on the motorway and falling off on soft ground in the boonies is a world apart. I've t-boned a pedestrian at 50 before and that wasn't very pleasant - getting filled in by a Polish HGV would have made my day very bad indeed! Lottery ticket it is.....