Junior TT
The Junior TT is a motorcycle road race that takes place during the Isle of Man TT festival; an annual event at the end of May and beginning of June. Between 1949 and 1976 this race was part of the Grand Prix motorcycle racing season.
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 motorcycle 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.
| Years | Maximum Engine Capacity |
| 1911 | 300cc 340cc |
| 1912 - 1976 | 350cc |
| 1977 - 1994 | 250cc |
| 1995 - 2004 | 600cc |
| 2005 - Present | 600cc 675cc 955cc |
Eligibility
Entrants
- Entrants must be in possession of a valid National Entrants or FIM Sponsors Licence for Road Racing.
Machines
- Any machine complying with the following specifications:
- * Supersport TT:
- ** 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
Official qualification time
- 115% of the time set by the third fastest qualifier in the class.
Speed and lap records