Mavic switch to full carbon clincher rim

The new Cosmic Pro Carbon SL C and Cosmic Pro Carbon SL C wheelsets feature technology that represents a step forward for the French firm, due to the improved resilience of the carbon layup, and has allowed Mavic to switch to a full carbon rim. Previously, Mavic used an aluminium insert in the rim bed in order to help dissipate heat and to address safety concerns surrounding the performance of a carbon clincher rim under heavy and prolonged braking.

The change has been made possible thanks to new techniques developed by Mavic in moulding the carbon layers into a single, seamless piece so that the aluminium insert is now no longer required.

“Instead of using aluminium to fight high temperatures under extreme braking and protect the rim – something we used in our first generation of carbon clincher wheels – we’ve now developed a new way of moulding the carbon in a single piece,” says Maxime Brunand, Product Line Manager for Mavic.

Wider rim for wider tyres

Both the Ksyrium and Cosmic rims have a 17mm internal width and are 25mm wide at the brake track, and Mavic say this optimally supports a 25mm tyre, which has become the standard across the industry over the past couple of years, and the width of rubber specced on these wheels.

Speaking of which, Mavic sell their wheels as a complete Wheel Tyre System, and the tyres supplied are Mavic’s own Yksion Pro Griplink at the front, and Yksion PowerLink at the rear. The two tyres are front and rear specific, with the Griplink designed to improve front wheel cornering grip by uses a sticky compound and ‘water evacuation tread pattern, while the Powerlink focuses on lowering rolling resistance. The tyres weigh a claimed 210g a piece.

Updated aero rim profile

Mavic’s wind tunnel has also been put to good use, with extensive testing resulting in a new aero profile being introduced for both wheelsets.  Mavic arrived at the NACA (National Advisory Committee for Aeronautics) airfoil profile after a lot of trial and error with different NACA profiles to find what produced the best results in the wind tunnel. Mavic claim the final shape offers improved stability and aerodynamic efficiency at the wind angles cyclists spend most of their time fighting.

“Across these average wind directions, we find our new wheels save watts in relation to our rivals. The new Cosmic Pro Carbon SL, for example, beats Zipp’s Z303 Firecrest 46mm rim by 2.3 watts over these yaw angles, at a range 10 degrees left-to-right,” says Brunand.

Hubs and spokes

The wheelsets all take advantage of Mavic’s alloy Instant Drive 360 hub design – a dual ratchet system introduced last year at the launch of the Pro Allroad range, engaging at just nine degrees with the scope to be compatible with any type of retention system.

The straight-pull, double-butted bladed spokes remain constructed of stainless steel for both the Cosmic and Ksyrium ranges – with the Cosmics benefitting further from Mavic’s wind tunnel work with a new tapered aero design. Each are laid out in a radial 18-spoke front and Isopulse 24-spoke rear pattern for optimum power transfer. That Isopulse pattern sees the spokes laced radially on the driveside and two-cross on the non-driveside to maximise driveside dish, thus providing a better spoke tension balance between left and right flanges.

Availability and pricing

Availability in the UK varies with each model: the new Cosmic Pro Carbon SL C goes on sale on March 15 (£1,450 RRP), while there will also be disc sibling available a month later (£1,500 RRP). A tubular version of the disc model is already available for £1,650 RRP, while the rim brake tubular version will be on sale from July 1 (£1,575 RRP).

The new Ksyrium Pro Carbon SL carbon clincher wheelset will be available from June 1 (£1,500 RRP for rim brake, £1,575 RRP for disc-specific), while rim and disc brake tubular versions are already on the market at the same price points as their Cosmic tubular siblings.

Try before you buy

Finally, Mavic are to launch a new try-before-you-buy testing program for their range of wheelsets, called Riding is Believing.

The program offers the chance for riders to test potential wheelset purchases from selected local dealers before they buy them, free of charge.

“We’ll be working with around 1,500 selected dealers at launch, with the potential for more,” says Brunand. “All riders have to do is register for the wheels online and pick them up at their chosen dealer to ride them. Then they have the opportunity to give us feedback on whether they met their expectations, and buy them if they did.”

The Riding is Believing program is due to launch on April 15 in the UK.

Website: Mavic