The European Tyre and Rim Technical Organisation (ETRTO) exists to specify and harmonise sizes of rims and their associated
pneumatic tyre
A tire (North American English) or tyre (Commonwealth English) is a ring-shaped component that surrounds a wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide traction on the surface over w ...
s across the
European Union
The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...
. ETRTO sizes apply to rims and tyres for vehicles of all types. It is probably most well-known for size standardisation of bicycle tires designations in millimeters, which replaces many older national methods for referring to tire sizes that are incompatible. The great advantage of ETRTO sizing is that it is unambiguous; previously, nominal dimensions were used which were interpreted in different ways by different countries and manufacturers - a problem for the end user.
ETRTO works in liaison with the
International Organization for Standardization
The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries.
M ...
to develop relevant standards.
List of ISO committees in liaison with ETRTO
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Motivation
Previously, one could for example risk buying a 28 inch tire for a 28 inch rim, with the result that the tire would not fit since 28" can refer to rim bead diameters of either 635 mm or 622 mm. Thus, a tire for one type of 28" inch rim will not fit the other, and vice versa. Another example is the rim sizes 406 mm and 451 mm, which both traditionally have been referred to as 20 inch (and obviously are not cross-compatible).
ETRTO solves these problems by precisely referring to rim bead diameters in millimeters.
Bicycle tire sizes
The following is a list of different types of bicycle tires listed by bead diameter according to ETRTO:
See also
* ISO 5775 – standard bicycle tyre and rim designations
* Uniform Tire Quality Grading
Uniform Tire Quality Grading, commonly abbreviated as UTQG, is a set of standards for passenger car tires that measures a tire's Wear#Abrasive_wear, treadwear, Thermal diffusivity, temperature resistance and Traction (engineering), traction. ...
* Tire bead
A tire (North American English) or tyre (Commonwealth English) is a ring-shaped component that surrounds a wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide traction on the surface over w ...
* Tubeless tire
A tubeless tire ( also spelled as tubeless tyre in Commonwealth English) is a pneumatic tire that does not require a separate inner tube.
Unlike pneumatic tires which use a separate inner tube, tubeless tires have continuous ribs molded integra ...
* Tubular tire
A tubular tyre, referred to as a tub in Britain, a sew-up in the US, a single in Australia, or just a tubular is a bicycle tyre that is stitched closed around the inner tube to form a torus. The combination is then glued (sometimes with two-si ...
References
External links
ETRTO home page
Motor trade associations
Pan-European trade and professional organizations
Standards organisations in Belgium
Tire industry
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