For over 100 years the world's best motorcycle racers have pitted themselves against the gruelling 373/4 -mile Isle of Man Mountain Course at the annual event known worldwide simple as 'the TT'. The Tourist Trophy meeting - to give its proper name - represents perhaps the greatest challenge that the sport of motorcycle racing can offer. The top names in road racing - Collier, Wood, Duke, Hailwood, Agostini, Hislop, Jefferies, McGuinness, Hutchinson and the Dunlop dynasty - have all considered the pursuit of a Tourist Trophy to be the ultimate goal. From riding the earliest single-cylinder, belt-driven machines with outputs of under 10bhp, to coping with today's sophisticated four-cylinder machines giving well over 200bhp, generations of riders have risked their lives to satisfy the desire to go faster than the next man and to win a TT. In the process they have lifted lap speeds by almost 100mph. Exactly how that huge increase has been achieved is told within these pages, set against the background of the triumpsh and the tragedies of the TT history.