Unbeknown to most cyclists, a Brussels-based organisation, called the European Tyre and Rim Technical Organisation, most commonly known as ETRTO , has been debating the safety of hookless (straight walled) wheel rims and compatible road bike tires . And their decision could impact your ride.
Made up of experts from wheel and tire manufacturers, the ETRTO committee is responsible for producing the recommended safety standards on, as you might have guessed, all aspects of wheel rims and tires – including those on bikes.
The issue that is seemingly dividing the industry is an apparent U-turn on the committee’s previous recommendation on internal rim width and the tires that are compatible with them.
ETRTO’s new standard states that there should be a minimum of a 5mm overlap between the internal measurement of a rim and the size of the tyre fitted to it. This means that previously popular combinations of 25mm internal rims and 28mm tyres now sit outside the new guidance. The Enve SES 4.5 aero road wheel features a 25mm internal hookless internal rim and suggests using a 27-29c tire for best aerodynamic performance According to Mavic’s Global PR Manager Michel Lethenet, the change “results from a world leading tyre manufacturer, which has demonstrated that a 28mm tyre mounted on a 25mm rim could derail from the rim.”
“The reason why it’s creating such debate is that 28mm tyres on 25mm internal hookless rims are proven to create a really aero profile” Patrick Blake, Lead Product and Commercial Manager at Hunt Bike […]
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