automobiles A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, Car seat, seat one to eight people, have four wheels, and mainly transport private transport#Personal transport, peopl ...

(and other wheeled vehicles which have two wheels on an

axle An axle or axletree is a central shaft for a rotation, rotating wheel and axle, wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In ...

), the axle track is the distance between the hub flanges on an axle. Wheel track, track width or simply track refers to the distance between the centerline of two wheels on the same axle. In the case of an axle with dual wheels, the centerline of the dual wheel assembly is used for the wheel track specification. Axle and wheel track are commonly measured in millimetres or inches.

Common usage

Despite their distinct definitions, ''axle track'', (not to be frequently and incorrectly used interchangeably as ''wheel track'' and ''track width''), normally refers to the distance between the centerline of the wheels. For a vehicle with two axles, the term can be expressed as ''front track'' and ''rear track''. For a vehicle with more than two axles, the axles are normally numbered for reference.

Offset wheel track

In vehicles with offset wheels, wheel track is distinct from axle track because the centreline of the wheel is not flush with the hub flange. If wheels of a different offset are fitted, the wheel track changes but the axle track does not.

Railroad context

In the railroad industry, the term "axle track" is not used; the same concept is called "flange gauge" or "wheel gauge". It is measured on a wheelset of a

railroad car A railroad car, railcar (American English, American and Canadian English), railway wagon, railway carriage, railway truck, railwagon, railcarriage or railtruck (British English and International Union of Railways, UIC), also called a tra ...

tram A tram (also known as a streetcar or trolley in Canada and the United States) is an urban rail transit in which Rolling stock, vehicles, whether individual railcars or multiple-unit trains, run on tramway tracks on urban public streets; some ...

from one wheel flange reference line to the reference line of the other wheel. It must be compatible with the "

track gauge In rail transport, track gauge is the distance between the two rails of a railway track. All vehicles on a rail network must have Wheelset (rail transport), wheelsets that are compatible with the track gauge. Since many different track gauges ...

" – the distance between the facing edges of the running rails – of the network it runs on. The maximum and minimum limits to the differences between the two gauges are usually 1" and " (9–35 mm).

Model railroads

Model railway elements such as track,

rolling stock The term rolling stock in the rail transport industry refers to railway vehicles, including both powered and unpowered vehicles: for example, locomotives, Railroad car#Freight cars, freight and Passenger railroad car, passenger cars (or coaches) ...

and

locomotive A locomotive is a rail transport, rail vehicle that provides the motive power for a train. Traditionally, locomotives pulled trains from the front. However, Push–pull train, push–pull operation has become common, and in the pursuit for ...

s are categorised by their wheel or track gauge. An HO scale or OO gauge model locomotive, for example, has a wheel gauge of 16.5mm.

References

{{Chassis control systems Automotive engineering Track gauges Train wheels

Common usage

Offset wheel track

Railroad context

Model railroads

See also

References