Mavic Cosmic Carbone 40c carbon clincher wheels

Three years in development, Mavic has released details of its ‘carbon clincher’ wheel – the Cosmic Carbone 40c – a wheel that they said they’d never make.

Carbon clinchers have been on the market for some years but not every manufacturer has adopted them, including Mavic – arguably the largest name in wheels – until now. Carbon clinchers are something the French manufacturer has previously said it would never make and yet this isn’t a volte-face. Let us explain…

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Building a clincher wheel out of carbon is a straightforward process, you just copy the shape of an extruded aluminium box section rim. The problem is that when you go downhill and brake, you heat up the very part of the rim that is holding the tyre securely. As it heats, the carbon resin starts to become malleable and the force of the air in the inner tube is trying to push the sides apart so that the tyre comes off with obvious results.

In simple terms, to get around this carbon wheel manufacturers have to add material and/or expensive heat resistant carbon and resin, which adds weight and cost – just what you don’t want to do.

Mavic has long resisted doing this and continues to do so in its new wheel, instead they have been very clever and created a thin alloy box and built a carbon rim around it, so you get the best of both worlds. One of the proprietary keys to this is TgMax, a special carbon resin element which chemically bonds the carbon to the alloy section.

The first wheel to use this technology is the Cosmic Carbone 40c. A catchy name it’s not, but the technology inside the wheel shows that the French company has really done its homework. Below we’ve listed the wheel highlights:

– 40mm windtunnel optimized rim profile

– 1545g, 670g front and 875g rear

– 2085g, wheelset including innertubes and Mavic 190gram Yksion Pro tyres

– TgMax resin technology (Maximum Glass Transition Temperature)

– A new brake surface treatment that gives 45% improved braking in the wet using standard yellow Swiss Stop pads

– Carbon and alloy hubs previously seen on the Cosmic CXR-80 wheels

– Priced 2000 euros, UK prices are yet to be confirmed

Fore drilling with integrated nipples and alloy inserts for ease of service