The Junior TT race was initially led by Eric Williams, the winner of the 1914 Junior TT race riding an AJS and set a new Junior lap record of 44 minutes and 6 seconds, an average speed of 51.36 mph. A mechanical retirement for Eric Williams allowed Cyril Williams also riding an AJS to build up an impressive lead of 20 minutes. However, Cyril Williams hit gear-box problems at the Creg-ny-Baa corner on the last lap and free-wheeled and pushed to the finish-line located at the Nobles Park playing fields in the town of Douglas. The winning margin for Williams was 9 minutes and 50 seconds from Jack Watson-Bourne, riding for Blackburne motorcycles in 4 hours, 37 minutes and 57 seconds, at an average race speed of 40.74 mph.
The Lightweight class within Junior TT race was won by Ronald Clark riding a Levis and he may have won the event overall but was thrown from his Levis motor-cycle at the Creg-ny-Baa after a puncture on the last lap. After completing the race on a bent front wheel-rim he was detained in Nobles Hospital after the race with physical exhaustion.
Senior TT 500 race
The Senior TT race was won by Tommy de la Hay riding a Sunbeam at an average race speed of 51.79 mph from local Isle of Man competitor Doug Brown riding a Norton. A new lap record was set by George Dance riding a Sunbeam of 40 minutes and 43 seconds, an average speed of 55.62 mph. AJS thought they could repeat the success of the 1914 Junior TT with a newly developed ohv-engined machine. While Cyril Williams won the Junior race for AJS, H. R. Davies, also on the AJS team, retired from both races with engine trouble.
Race awards and classes
The 1920 Junior TT race included for the first time a new Lightweight TT class for motorcycles of 250 cc engine capacity. Ronald Clark riding for the Levis marque finished in 4th place overall and was within the 30 minute limit for The Motor Cycle Cup Trophy for the smaller 250cc motor-cycles.
Race results
Junior TT 350cc
Held on June 15th, at 9:31 am over a distance of 188.75 miles, limited to machines of cylinder capacity not exceeding 350cc., with a class for 250 cc. engines run concurrently for The Motor Cycle cup.Out of 32 entries, comprising 8 two-strokes, 16 four-stroke Singles, 7 Flat Twins and 1 V Twin, twenty-four started the race and only eleven finished.
Senior TT 500cc final standings
Held on June 17th, at 9:30 am over a distance of 226.50 miles, limited to machines of cylinder capacity not exceeding 500cc.Out of 29 entries, comprising 21 four-stroke singles, 5 V Twins, 3 Flat Twins and no two-strokes. Twenty-seven riders started the race and fourteen finished.
