Cyclist
Vittoria’s lightbulb moment: new 29mm Corsa Wide Rim tyres are optimised for 25mm rims
Vittoria has launched a range of Wide Rim tyres, which are designed to sit with a flatter sidewall on 25mm internal width rims, a size that is increasingly common in modern road bike wheels.
Sold in 29mm width only, the new Wide Rim tyres are available now for the Corsa Pro and Corsa N.Ext, with prices of £89.99 and £69.99 respectively. A Corsa Pro Speed Wide Rim tyre is due to be launched later in the year.
A more aero profile
Wheel aerodynamics has progressed significantly in the last few years and wider rims, designed to fit tyres of 28mm and wider are now common in the highest performance road bike wheels. But there are further aero gains from optimising the wheel and tyre as a system and avoiding a lightbulb-shaped profile to the tyre.
A flatter interface between the wheel rim and the tyre sidewall can improve the airflow and it’s that which Vittoria’s new Wide Rim 29mm tyres are designed to promote.
Why 29mm? Because that’s the minimum width for compatibility with 25mm internal width rims recommended by ETRTO, which sets wheel and tyre standards.
Vittoria says that the combination of its 29mm tyre with a 25mm internal width rim offers the smoothest tyre to wheel transition and hence the least turbulence at the interface. It claims that this can save up to 5 watts at 55km/h relative to a Corsa Pro 28mm tyre on a standard 19-21mm width rim. The flatter sided profile also increases cornering grip, it says. Both gains are claimed for the Corsa N.Ext and Corsa Pro Speed too.
Vittoria notes that you can still use the Wide Rim tyres on rims narrower than 25mm, although this will reduce the tyre width. All the Wide Rim tyres are compatible with hookless rims.
The rest of the tyre’s formula hasn’t changed, with the Corsa Pro Wide Rim having the same 320 TPI cotton casing and graphene plus silica tread compound that’s electrically vulcanised. The tyre also has Vittoria’s anti-puncture belt under the tread and Bead Shield, designed to protect the tyre bead.
The Corsa Pro Wide Rim tyre comes with tan sidewalls and Vittoria says it’s made in a carbon-neutral factory. It claims a 290g weight for the tyre, which is priced at £89.99 / €95.95 / $106.99.
It’s seen action with Visma-Lease a Bike on the team’s Reserve 40|44 wheels, which have differential 25.4mm front and 24.8mm rear internal rim widths and 52|63 wheels with 25mm F/24mm R widths.
And Corsa N.Ext and Corsa Pro Speed Wide Rim tyres
As with other Corsa N.Ext tyres, the Corsa N.Ext Wide Rim tyre has a 100 TPI nylon casing, a thicker tread than the Corsa Pro and comes with black sidewalls. It too has an anti-puncture belt and Bead Shield, but also adds an extra ply in the inside face of the casing to increase puncture protection. Vittoria claims a 310g weight for the tyre, which is priced at £69.99 / €71.95 / $91.99.
Finally, the yet-to-be-released Corsa Pro Speed Wide Rim tyre has a tan sidewall 320 TPI cotton casing and Bead Shield, but forgoes a puncture protection belt under the tread. Vittoria claims a 255g per tyre weight and carbon-neutral production. Its price is the same as the Corsa Pro Wide Rim at £89.99 / €95.95 / $106.99.
Aero tyres are a trend
Vittoria isn’t the first tyre maker to launch tyres designed to be more aero or to work with wider rims. In fact, it’s something of a trend.
Goodyear worked with Zipp to produce tyres designed to work with Zipp’s 25mm wide rims, while Cadex has tyres that are aero optimised, sitting with flatter sides on its Cadex 50 Ultra Disc wheels.
Continental’s Aero 111 front tyre has a tread pattern and shape that’s designed to provide aero benefits and was used to aero optimise the latest wheels from DT Swiss/Swiss Side. It’s available in 26mm and 29mm widths.
Schwalbe too has an aero tyre, the Pro One Aero, which it claims offers 22 percent lower air resistance than its Pro One TT tyre.
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