The Supertwin TT is a motorcycle road race that is a part of the Isle of Man TT festival - an annual motorcycle event traditionally held over the last week of May and first week of June. Prior to the 2022 edition of the TT, the race was known as the Lightweight TT.
History
The Lightweight class, as it was then known, was first present at the 1920 TT races, as a category in the Junior TT. However it was not until 1922 that the first time the Lightweight TT took place, won by motorcycle journalist Geoff S. Davison riding a Levis, at an average speed of 49.89 mph (80.29 km/h) for 5 laps of the Snaefell Mountain Course.
Between 1949 and 1976, the Lightweight race was part of the Grand Prix motorcycle racing season.
In the changes following the loss of FIM World Championship status after the 1976 event, the Lightweight TT event was dropped with the 250 cc machines running for the Junior TT in place of the now defunct 350 cc formula. The Lightweight TT returned in 1995 before being split into two distinct events from 1999, dropping from the schedule again after 2004.
The Lightweight TT and the Ultra-Lightweight TT were later reinstated to the 2008 & 2009 race schedules, but were held on the 4.25 mile Billown Circuit in the south of the Isle of Man.[1] For the 2010 races, the Lightweight TT was again dropped from the race schedule on cost grounds.
The event was re-introduced for the 2012 races on the Mountain course, with a change to water-cooled four-stroke twin cylinder engines not exceeding 650 cc and complying with the ACU Standing Regulations.[2]
There have been several different categories of motorcycle that can compete in this event. In the 1950s and 1960s, the principal TT solo events were the Senior (500 cc), Junior (350 cc), and Lightweight (250 cc, or sometimes 125 cc). The 125 cc class was occasionally called the "Ultra-Lightweight" class.
Currently the Lightweight class comprises road-based "Super-Twin" solo machines with liquid-cooled four-stroke engines of up to 650 cc engine capacity.
Overview
1924–1948: For motorcycles not exceeding 250 cc engine capacity.
1949–1953: FIM World Championship event for motorcycles not exceeding 250 cc engine capacity, held on the Snaefell mountain course.
1954–1959: FIM World Championship event for motorcycles not exceeding 250 cc engine capacity, held on the Clypse Course.
1960–1976: FIM World Championship event for motorcycles not exceeding 250 cc engine capacity, held on the Mountain Course.
1977–1994: event not run (250 cc formula run as Junior TT).
1995–1998: For 2-stroke motorcycles not exceeding 250 cc engine capacity and 4-stroke motorcycles not exceeding 400 cc, held on the Mountain Course.
1999–2003: Lightweight 400 TT for 4-stroke motorcycles not exceeding 400 cc engine capacity, held on the Mountain Course.
1999–2002: Lightweight 250 TT for 2-stroke motorcycles not exceeding 250 cc engine capacity, held on the Mountain Course (the category running within Junior TT in 2003).
2008–2009: For motorcycles not exceeding 250 cc engine capacity, held on the Billown Circuit.
2012–2019: For water-cooled four-stroke twin cylinder not exceeding an engine capacity of 650 cc and complying with the ACU Standing Regulations.[4]
Speed and lap records
The lap record for the Lightweight TT is held by Michael Dunlop in a time of 18 minutes and 26.543 seconds, at an average speed of 122.750 mph (197.547 km/h) set during the 2018 race. The race record for the 4 lap (150.73 miles/242.58 km) Lightweight TT is a time of 1 hour, 15 minutes and 05.032 seconds, at an average race speed of 120.601 mph (194.088 km/h), also held by Dunlop during the 2018 race.[5][6]
^International Isle of Man TT Regulations 2012 page 41-42 Appendix-E ACU Events (Isle of Man) Ltd (2012) Isle of Man Department of Economic Development
^International Isle of Man TT Regulations 2012 page 41-42 Appendix-E ACU Events (Isle of Man) Ltd (2012) Isle of Man Department of Economic Development
