Mavic Cosmic Carbone SLR [en]

Publié le par Adrien

In 2007, Mavic released a new wheel concept. The TraComp technology pushed the French manufacturer at the top of the high-end aluminium range. In 2008, the company from Haute-Savoie is releasing another system, which seems as promising, and should open doors to several further upgrades in subsequent ranges.

The SLR version of the Cosmic Carbone is the first wheelset to benefit from the R2R concept. The aluminium rim is still equipped with the carbon twill weaved "fairing", and the hub remains in aluminium. The spoking is identical at the front and rear: 20 spokes ensure the integrity of the wheel. The spoking is unusual - more details below. Mavic claims the SLRs weigh in at 1595g.

R2R, a promising concept
The R2R technology used on the Cosmic Carbone SLR looks a lot like the rim to rim spoking of the Cosmic Carbone Ultimate or Lightweight wheels. However the similarity stops here. Indeed the two high end models have their spokes molded into the rims and wrapped around the hub. This spoking is different since the carbon fibre spokes only pass through the hub and are screwed to the rim, like a conventional spoke. Actually, each spoke is double, and a 20 spokes wheel is composed of 10 actual double spokes.
The threaded tip of the spoke, at the rim diameter, is identical to the spokes on non drive side of the rear Cosmic Carbone Ultimate: the spoke is widened to receive a threaded metallic insert (see on this picture)

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Regarding the materials, the SLR spokes are unidirectional carbon. However they differ from the spokes of the Ultimate version on several points. Oval and looking raw on the Ultimate, their section is here rectangular and they are much glossier, almost like a plastic at close range.
Well, the spokes tensions on these wheels are very high on the drive side of the rear wheel, but much lower on the front. It's hard to give any figure here since we do not have the spoke tension chart, it's only a feeling.
The spokes of the rear wheel are differentiated: the thickness of the drive side spokes is 1,5mm, while it is only 1mm, both on the non drive side of the rear wheel, and on the front wheel. The lateral stiffness balance, on the both sides of the rear wheel has been optimized here.

The advantage of the concept is indisputable: it is the first "rim to rim" carbon spoked wheel, fully repairable, spoke by spoke. Exaggerating slightly, we could even say it's a Cosmic Carbone Ultimate without the disadvantage of the irreparable monobloc wheel. However we wouldn't push it that far, although it's what we have to expect in some years.
The weight of the Cosmic Carbone SLR remains quite high despite the spokes upgrade. Our scale displayed 1630g the set. In hand, the rotational inertia were particularly high too, meaning a hefty rim and difficult accelerations. The test on the road may show a different behavior.
This first wheel featuring the R2R spoking could have been more exciting, its technical and weight advantages are hidden by a massive, incoherent and old construction: aluminium rim with carbon fairing, alloy hub, plastic caps. All these parts are not really on the level of the evolution coming along with the new spoking. We are waiting for further, more exciting evolutions of this innovative concept.

Evolutions at every level

The components of the CCSLR remain visually identical to the previous Cosmic Carbone. Nevertheless the aluminium rim is lightened of 20g between the spokes, which translates into lower rotational and translational inertia. The carbon walls still bring the aerodynamic touch we look for from a Cosmic: the complete rim height is 52mm. With the very thin spokes, the aerodynamic performances should be amongst the best.

The hub is obviously redesigned to receive the R2R spoking passing through each flange. Still made out of aluminium, the hub receives the usual Mavic mechanism. The bearings are smooth but quite tight, they will very certainly get much easier to turn with a few hundred kilometers.

Carbon spokes, comparizon

About the spokes, as announced above, the unidirectionnal carbon is used. When looking at a set of Lightweight, Cosmic Carbone Ultimate, or Lew at some meters, it's impossible to tell which one belongs to which wheel. At very close range, the task is as difficult if the rims and hubs are hidden. Are you able to tell for sure who are these spokes on the left picture...?

Basically, the differences are mostly about the shape: rectangular on the CCSLR, oval on the LW, CCU and Lew.

The manufacturing process is what differentiates these spokes. The Lightweight and Cosmic Carbone Ultimate use double carbon spokes molded into the rim and wrapped around the hub, the Lews have carbon/boron bonded to the rim and the hub. The Cosmic Carbone SLR features double carbon spokes put against the hubs and screwed at the rim interface.
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Finally, we have to conclude that Mavic has, once again delivered a useful innnovation. It is the first full carbon, rim to rim spoking, coming along with lightness: the CCSLR are 145g lighter than the CCSL, stiff and, above all, entirely repairable.
The price is expected to be around 1400 euros.

Publié dans Matériel || Stuff

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