The regulations changed once again for the 1910 race, which was held at the end of May.
This proved to be the last TT on the St John's Course, which now featured a wooden banking section to protect the riders from the jagged wall at the left-hander at Ballacraine.
The motorcycle industry had really got the message that racing was the perfect way to test products and parts and 83 machines were entered, half of them twins. The TT was turning into a tough, competitive battle to improve sales between the factories. It was an exciting time and exactly what Freddie Straight had envisaged when he drew up that first set of regulations.
There were worries about the speed of the modern machinery, with the twins lapping at over 50 mph. Because of this, and their success the year before, their capacity was reduced to 670cc, but, as in modern times, the restriction made no difference to the bikes' record-breaking performances. In fact, the record lap speed was increased to 53.15 mph by Harry Bowen on his BAT twin, although he failed to finish when he crashed on that wooden banking at Ballacraine.
The race was a great triumph for the Collier brothers and their twin-cylinder Matchless machines. Charlie won at a record-breaking 50.63 mph, with Harry second in front of the single-cylinder Triumph of Billy Creyton. They did not have it all their own way, however, with the BAT twins giving them an especially hard time until forced out. The German NSU concern had also produced a very quick twin; the race was becoming more international and was talked about throughout the Continent.