First Impressions: Early Miles on the Mavic Cosmic Carbone 40 C
They aren’t first to the carbon clincher market, but Mavic believes they have solved the heat issue that plagues the segment.
By mixing the best properties of aluminum, carbon and resin, the French wheel maker says they have finally been able to create a carbon clincher that meets their standard. As usual there is a lot of talk about special resins and proprietary technologies, but as always, the proof is in the riding. We got to take a pair for a few days before they needed to head out to Sea Otter for some initial testing. Read on to find out our first impressions…
Carbon does a lot of things well, but the resin that holds it together has one crucial flaw- heat dissipation. Every manufacturer has had to deal with this problem, and each touts their own way of solving it. Mavic has come to the table with a mix of what has become industry standard procedure and their own new methods.
First, like many others, they have a proprietary resin treatment, called TgMAX, that they claim dissipates heat better than the competition. These claims are all but impossible to substantiate. It’s what’s under the carbon where Mavic departs from most others. Mavic uses an aluminum tire bed and bead hooks, called the spine, as the core. The carbon is then affixed over that core using more proprietary technology. Mavic PR man Zack Vestal did say that the process is chemical and purportedly strengthens over time. This combination of aluminum, carbon and TgMAX is claimed to provide heat dissipation properties that others can’t match.
Additionally, the entire rim is structural, which should enhance overall stiffness. Vestal also pointed out that the aluminum core provides better tire fitment, holds air pressure better and resists pulsing.
Of course a wheel is more than just the rim. The 40 C is meant to be a one wheel solution. With that in mind, the rim is a middle of the road 40mm deep with a slightly blunted shape. Mavic keeps it narrow at 19mm. The hubs are the same carbon/aluminum ones found on high end models. The steel spokes, 20 front and rear, are laced radially except the 2-crossed rear drive side. Like all carbon rimmed wheels, special brake pads are needed, in this case they’re classic yellow SwissStop pads.
So what does all of this weigh? Surprisingly, the front is 670g and the rear comes in at 875g for a total of 1545g. The competitor most referenced by Mavic, the Zipp 303, comes in 70g lighter.
All of this sounds great, but the big question as always is does it work? Unfortunately, between the spring snow and these wheels needing make their way to Sea Otter, I only had four rides on them, so my review was limited. We are hoping to get a set for long term test, so the following is just a start:
I threw the 40 C’s on a demo bike that was equipped with 105 level brakes, so my stopping power was already slightly compromised. Not willing to lay it all out on the first ride, I chose the flat roads of east Boulder for the first miles. With the first pull of the levers it was obvious this was more about merit than marketing. Initial bite is solid but not overly so. The power comes smoothly without any grabbing or dead spots and was more than adequate to bring me to halt quickly. Of course many wheels do well on flat roads, where the heat build up is minimal. For the last rides I did get into Boulder’s foothills. I meandered up Left Hand Canyon to Lee Hill, then bombed back into town along the twisty road. On my last ride I took the wheels up and over Old Stage, a notoriously steep but short climb. Both times I wanted to push the limits, but with sand on the roads and colder weather, a true test was not to be had. Still, coming down and hitting speeds over 40mph, I had every confidence in the wheels’ braking abilities. At no point was I grasping for more lever or “coming in hot”.
There is however, one very noticeable drawback. The noise. These wheels let out a high pitch shriek. From ride one it was present and it persisted throughout my time on them. Initially, it was only the front that screamed. Then, after a few corners and trying to lay on the brakes harder and longer, the noise abated. But shortly it returned, and this time it both wheels were screaming. If you were in a group ride or race, you would certainly get the stink eye. When I mentioned this to Vestal he noted that toeing in the brakes seems to help. This is something a long term test can hopefully confirm. Another issue I found was yellowing of the brake track. According to Vestal, the track is treated in some fashion (he couldn’t say exactly how), and that seemed to be wearing the Swiss Stop pads. You could probably get this coloring out with some good ol’ scrubbing, but that would be a continual task.
It’s important to note that these wheels do perform in other areas. Getting up to speed is not an issue – they spin up quickly. They also exhibit very little lateral flex. When sprinting in the drops I could not get the rims to hit the pads no matter how I tried. This stiffness also translates to crisp handling. In cross winds they are solid, though they aren’t as solid as those with the fully blunted shaped. In terms of being a one wheel solution, I would say that is an accurate claim, though I can’t fully speak to their durability.
We are hopefully going to be putting more miles on these wheels. While initial impressions are very favorable, testing these under more severe conditions is needed before giving them the full stamp of approval. If the 40 C is a solid as Mavic claims, it could very well be another wheel to consider.
- Rim Material – 3k Carbon with Aluminum Reinforcement
- Brake Track – Carbon with TgMAX
- Rim Depth – 40mm
- Rim Width – 19mm
- Spokes – Steel Bladed Straight Pull, 20 F/R
- Hubs – Carbon Center w/ Aluminum Flanges, Sealed Bearings
- Weight – 670g F/ 875R – 1545g pair (claimed)