When Michael Dunlop parades the Black Eagle Racing 500cc Gilera four at the Classic TT on August 28, he will get an insight into the problems faced by riders in the ‘dustbin” era of Grand Prix racing in the mid-1950s.

The bike is a copy of the factory machine on which Bob McIntyre recorded the first 100mph lap of the TT course. It will carry the dustbin streamlining that enclosed the front wheel of bikes of that era, and which added 10-12mph to the top speed of a 500cc machine. But the hand-beaten aluminium fairing and its bracketry carries a weight penalty, and alters the geometry of the machine.

“The fairing and brackets weigh 20-25lb, and the complete bike will weigh about 325lb,” Black Eagle director Mark Kay told bikesportnews.com. “We’ve jacked the front springs up to allow for the fairing. It's mounted so far forward that it puts a lot more weight on the front end.”

Dunlop will confront a twin-cam, transverse four-cylinder machine with a five-speed gearbox and an output of about 62-65bhp. That made the 500cc Gilera four the most refined Grand Prix motorcycle of its day - McIntyre won the 1957 eight-lap Senior TT with a fastest lap of 101.12mph, and Italian Libero Liberati gave Gilera its fifth 500cc world title in six years.

Dustbin fairings first appeared in about 1954, and became essential equipment for any serious Grand Prix machine. But there were problems with side winds, front-end loft and brake cooling, and the FIM banned these beautiful shapes at the end of the 1957.

Sixty years on from Bob McIntyre’s epic lap, Michael Dunlop will get an insight into what world championship racing was like in the era of John Surtees and Geoff Duke.