The Auto-Cycle Union is governing body of motorcycle

Motorcycle

A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...

 sport in Great Britain

Great Britain

Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

 (not Northern Ireland

Northern Ireland

Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west...

, which is governed by the MCUI, the All Ireland

All Ireland

All-Ireland is an attributive which emphasises the island of Ireland. It contrasts with expressions such as the South or Northern Ireland which apply only to regions. Many sports are organised on an all-Ireland basis....

 governing body, but including the Channel Islands

Channel Islands

The Channel Islands are an archipelago of British Crown Dependencies in the English Channel, off the French coast of Normandy. They include two separate bailiwicks: the Bailiwick of Guernsey and the Bailiwick of Jersey...

 and the Isle of Man

Isle of Man

The Isle of Man , otherwise known simply as Mann , is a self-governing British Crown Dependency, located in the Irish Sea between the islands of Great Britain and Ireland, within the British Isles. The head of state is Queen Elizabeth II, who holds the title of Lord of Mann. The Lord of Mann is...

). Founded in 1903 and acquiring its current name in 1907 its aim was to develop motor sport through clubs and arrange touring facilities for members. In 1904 it was a founding member of the Fédération Internationale de Motocyclisme

Fédération Internationale de Motocyclisme

The Fédération Internationale de Motocyclisme is the governing body of motorcycle racing. It represents 103 national motorcycle federations that are divided into six regional continental unions....

.

The 1911 Isle of Man TT

1911 Isle of Man TT

The 1911 Isle of Man Tourist Trophy races took place for the first time over the "Snaefell Mountain Course". The whole organisation of the races was given over to the Auto Cycle Union , who announced the use of the longer mountain course with a four lap Junior race on Friday 30 June and a five...

 was the first TT

Isle of Man TT

The International Isle of Man TT Race is a motorcycle racing event held on the Isle of Man and was for many years the most prestigious motorcycle race in the world...

 races to be organised by the ACU.

The sports covered in addition to non competitive motorcycling interests are: Grass Track

Grasstrack

Motorcycle Grasstrack is a form of motorcycle racing which typically, in its current form, takes place on a flat track consisting of two straights and two bends usually constructed in a field. Mountain and hillside tracks are also common in the UK, creating more technically demanding circuits...

 (Track Racing

Track racing

Track racing is a form of motorcycle racing where teams or individuals race opponents around an oval track. There are differing variants, with each variant racing on a different surface type....

), Enduro

Enduro

Enduro is a form of motorcycle sport run on courses that are predominantly off-road. Enduro consists of many different obstacles and challenges...

, Motocross

Motocross

Motocross is a form of motorcycle sport or all-terrain vehicle racing held on enclosed off road circuits. It evolved from trials, and was called scrambles, and later motocross, combining the French moto with cross-country...

, Road racing

Road racing

Road racing is a general term for most forms of motor racing held on paved, purpose-built race tracks , as opposed to oval tracks and off-road racing...

, Speedway

Motorcycle speedway

Motorcycle speedway, usually referred to as speedway, is a motorcycle sport involving four and sometimes up to six riders competing over four anti-clockwise laps of an oval circuit. Speedway motorcycles use only one gear and have no brakes and racing takes place on a flat oval track usually...

 and Trials

Motorcycle Trials

Motorcycle trials, also termed observed trials, is a non-speed event on specialized motorcycles. The sport is most popular in the United Kingdom and Spain, though there are participants around the globe....

.

The ACU also govern the safety standards for personal protection equipment worn during racing. Only motorcycle helmet

Motorcycle helmet

A motorcycle helmet is a type of protective headgear used by motorcycle riders. The primary goal of a motorcycle helmet is motorcycle safety - to protect the rider's head during impact, thus preventing or reducing head injury or saving the rider's life...

s which meet ACU standards and display the appropriate ACU sticker can be worn in "speed" competition. The majority of quality helmets sold in the UK now feature an ACU Gold sticker and many riders choose these for every day use in preference to those that meet the more basic BS6658:1985 legal requirement .