Tech issues

The UCI's new wheel regs

By John Stevenson, technical editor

New regulations came into effect January 1 governing the type of wheels that are legal for UCI competition, and as usual when the UCI makes a significant change to its regs there has been lots of heat about the changes, but not much light.

In outline, wheels for racing have to pass a 'rupture test' unless they conform to the UCI's definition of 'standard (traditional)' wheels. 'Standard' wheels have at least 16 metal spokes, spokes no larger than 2.4mm in any dimension, and the rim no larger than 25mm in cross-section.

The first thing to note here is that wheels that don't meet these requirements have not been banned. They simply have to pass the rupture test to be legal. The UCI has issued a list of wheels that pass, and that list is reproduced at the bottom of the page. It seems reasonable to expect this list to grow as more wheel manufacturers get their wheels certified.

The apparent object of the exercise here is to identify recently-developed wheels that may have sacrificed structural strength for light weight or aerodynamics or both. But what's annoying the UCI's critics is the apparently arbitrary nature of the distinction. It may be possible to build traditional wheels within the UCI's definition that would nevertheless fail the rupture test, and many wheels with deep-section rims are enormously strong but are caught in the net by the 25mm cross-section rule. It's not fair, say the UCI's critics, to pick on wheels for certain dimensional characteristics when what's really needed is a consistent and rigorous definition of a safe wheel. We've put these points to the UCI and we'll come back with their response when we hear from them.

For the meantime, though, there's no need to panic and throw away your wheels even if they're not on the list below. The UCI regs only apply to UCI races, and would have to be adopted by national federations before they affect your local C Grade crit.

For those who like chapter and verse, here's the full text of the new regulation.

Article 1.3.018

Wheels of the bicycle may vary in diameter between 70 cm maximum and 55 cm minimum, including the tyre. For the cyclo-cross bicycle the width of the tyre shall not exceed 35 mm and it may not incorporate any form of spike or stud.

For massed start road races only wheel designs granted prior approval by the UCI may be used. In order to be granted approval wheels must have passed a rupture test as prescribed by the UCI in a laboratory approved by the UCI. The test results must show that the rupture characteristics obtained are compatible with those resulting from an impact sustained during normal use of the wheel. The following criteria must be fulfilled:

• On impact, no element of the wheel may become detached and be expelled outwards.
• The rupture must not present any shattered or broken off elements, or any sharp or serrated surfaces that could harm the user, other riders and/or spectators.
• The rupture characteristics must not cause the hub to become separated from the rim in such a way that the wheel becomes detached from the forks.

Without prejudice to the tests imposed by the laws, regulations or customs, standard (traditional) wheels are exempted from the rupture test referred to above. A traditional wheel is deemed to be a wheel with at least 16 metal spokes; the spokes may be round, flat or oval, provided that no dimension of their cross sections exceeds 2.4 mm; the section of the rim must not exceed 2.5 cm on each side.

Notwithstanding this article, the choice and use of wheels remains subject to articles 1.3.001 a 1.3.003. (Article applicable as from 1 January 2002).

Non-standard wheels that conform to UCI article 1.3.018