Which late-summer event is described as an amateur version of the Isle of Man TT?

The late-summer event described as an amateur version of the Isle of Man TT is the Manx Grand Prix.

The Manx Grand Prix is held on the same 37.73-mile Snaefell Mountain Course, usually in late August or early September, several months after the main TT races. It is traditionally aimed at amateur, club-level and developing riders, making it an important learning route for competitors hoping to progress to the TT.

The event began in 1923 as the Manx Amateur Road Races and adopted the Manx Grand Prix name in 1930. A Newcomers class gives riders with no previous Mountain Course experience a chance to compete, subject to machinery and qualification limits.

A common mix-up is confusing the Manx Grand Prix with the Classic TT. The Manx Grand Prix includes modern and classic categories, while the Classic TT was a separate historic-racing feature introduced in 2013. Unlike the TT, the Manx Grand Prix does not include sidecar races.