Engine capacity
The 1911 Isle of Man TT was the first time the Junior TT race took place and was open to 300cc single-cylinder and 340cc twin cylinder motor-cycles and was contested over 5 laps of the new 37.5 mile Mountain Course. The first event on the new course was the Junior TT Race and was contested by 35 entrants. It was won by Percy J. Evans riding a Humber motor-cycle in 3 hours, 37 minutes and 7 seconds at an average speed of 41.45 mph.
The 1912 event was the first to limit the Junior TT to only 350 cc machines and this engine capacity prevailed until 1994.
Eligibility
Entrants
- Entrants must be in possession of a valid National Entrants or FIM Sponsors Licence for Road Racing.
Machines
The 2012 specification for entries into the Junior TT race are defined as;-
- Any machine complying with the following specifications:
- Supersport TT: (Machines complying with the 2012 FIM Supersport Championships specifications)
- Over 400cc up to 600cc 4 cylinders 4-stroke
- Over 600cc up to 675cc 3 cylinders 4-stroke
- Over 600cc up to 750cc 2 cylinders 4-stroke[1]
Official Qualification Time
- 115% of the time set by the third fastest qualifier in the class.[2]
Speed and Lap Records
The lap record for the Junior TT is 17 minutes and 35.659 seconds, at an average speed of 128.666 mph (207.068 km/h) set by Michael Dunlop on lap 2 of the 2013 Isle of Man TT 600cc Supersport Junior TT Race 2. The race record for the Junior TT is 1 hour, 11 minutes and 36.808 seconds at an average race speed of 126.445 mph (203.494 km/h) set by Ian Hutchinson during the 2016 600cc Supersport TT Race 1.[3][4]
Junior TT Race Winners
| Rider | Wins |
| Ian Hutchinson | 8 |
| Giacomo Agostini, Michael Dunlop, Stanley Woods | 5 |
| Bruce Anstey, Charlie Williams | 4 |
| Joey Dunlop, Freddie Frith, Jimmie Guthrie, Jim Redman | 3 |
| Alec Bennett, Brian Reid, Geoff Duke, Mike Hailwood, Gary Johnson, Con Law, Ian Lougher, John McGuinness, Chas Mortimer, Jim Moodie, John Surtees, Eric Williams | 2 |
| Rod Coleman, Percy J. Evans, Ryan Farquhar, David Jefferies, Ken Kavanagh, Dave Leach, Bill Lomas, Phil Mellor, Steve Plater, Michael Rutter, T. M. Sheard, H. G. Tyrell Smith | 1 |
Junior TT Race Winners by Marque
| Marque | Wins |
| Yamaha |
21 |
| Honda |
18 |
| Norton |
11 |
| MV Agusta |
9 |
| Velocette |
8 |
| AJS |
5 |
| Moto Guzzi |
2 |
| Cotton, Douglas, EMC, Gilera, Humber, HRD, Kawasaki, New Imperial, NUT, Rex-Acme, Rudge-Whitworth, Suzuki, Triumph |
1 |
Winners of Junior/Senior Double Isle of Man TT Races
