Exclusive clip from gripping bike doc ‘Road’

Later this week, a new DVD and BluRay will be digitally and physically stacked on the shelves. It's a new documentary called Road and tells the story of the Dunlops, the first family of motorbike road racing. Yes, it's about a film about life on two wheels, not four. But that doesn't mean it isn't brilliant. Because it is, as you can see from Top Gear's exclusive clips above.

Narrated by man of a very particular set of skills, Liam Neeson, Road is (a) improbably fast (b) very crashy in parts and (c) entirely worth a watch if you're into racing or speed or simply a delve into the psyche of men who pilot motorbikes at 180mph along country roads, eyeballing death time and time again until, at last, they run out of luck.

The Dunlops, for the uninitiated, are road-racing royalty. Road follows the story of two pairs of brothers: Joey (who notched up an unmatched tally of 26 wins at the Isle of Man TT between 1976 and 2000, widely recognised as the greatest road racer in history) and Robert (who managed five TT wins of his own), and Robert's sons Michael and William, both world-class road racers in their own right.

Road combines archive clips with some properly fearsome modern race footage - like the ones below. There are also interviews with Murray Walker - a former road racer himself - and John McGuinness, the only current racer with a realistic chance of overhauling Joey Dunlop's TT title haul.

We watched the film earlier this year and found that Road is worthy of its place among modern racing classics Senna and Closer to the Edge. At Road's heart lurks the curious, conflicted relationship between racers and mortality, be it their own or others. What pushes them to go faster and harder, time after time, when fatal accidents aren't so much a risk as an occupational hazard?

After all, it's no spoiler to note that Joey Dunlop lost his life to a racing crash in Estonia in 2000, with his brother Robert dying in a road race in Northern Ireland eight years later, incidents Road deals with in unflinching fashion. Why, if you'd lost your uncle and father to the same sport, would you keep coming back for more?

"It's the challenge of facing up to danger and overcoming it," says Murray Walker. "There's some sort of enormous spiritual satisfaction of controlling an enormously powerful piece of machinery on the knife-edge between safety and disaster..."

Road is available on DVD, Blu-ray and digitally from 29 September 2014 but you can watch the full trailers here.