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Reviewed: Mavic Cosmic Carbone SLR/SR Wheelset

We thought the Garmin team made a huge mistake when they chose Mavic as their wheel supplier over Zipp. Yes, the selection probably has more to do with bundles of cash than it does performance, but considering how Garmin claimed they were giving their riders the best tools, from physiologists to powermeters to yoga mats to Mavic Cosmic Carbone SLR/SRrecovery modalities, it was odd that they didn’t go the route of the Highroad team, go without a wheel sponsor and let the riders or directors choose what’s right for the given conditions.

Mavic, to us, leans toward the solid side of solid performance. Their wheels are undeniably popular for a very good reason. They’re strong verging on overbuilt, particularly for pro riders. They’re beyond reliable. Yes, the R-Sys has had some problems, we weren’t huge fans, but Mavic seems to have worked the problems out. We’ve never thought of them as cutting-edge aero or light. We’ve never seen a reason to test any Ksyrium, except maybe the first or second iteration, as wheels from this series are the standard by which others are measured. Not terribly light, not terribly aero, but light enough, aero enough, with reliable internals and plenty strong so that everyone can be happy with them.

Mavic Cosmic Carbone SLR/SRWe’ve done the Cosmic Carbone Ultimate and the R-Sys. Admittedly, this wheel, the 2010 Cosmic Carbone SLR (re-labeled Cosmic Carbone SR for 2011) didn’t really jump out at us. Plastic spokes with a carbon-fiber fairing on aluminum clincher rim didn’t seem that big of a deal. Look at the weight, 1595g claimed for a set, wonder why these wheels aren’t lighter. As a set, it doesn’t seem like much of a step forward.

We’re probably an outlier on this issue. The wheels sell. The CC SLRs quickly made a noticeable dent in our local race scene. And people weren’t just bringing them out for flat crits and rolling road races. We were seeing them in the hilly races as well. Maybe there is something more to it.

Our set of SLR’s came with one of the front hubcaps missing. Luckily, it was hidden underneath a flap of the box. All the same, the first generation of hub caps did have a tendency to come off easily as it only took mild hand pressure to remove and could be pressed on again by hand. Mavic made a running change on the caps and now you need a screwdriver to pop them off.

Mavic Cosmic Carbone SLR/SRThe caps cover an essential element of the spokes. These spokes run from the rim to the hub to the other side of the rim. While they’re carbon-fiber, there is an aluminum anchor that presses into the hub flange keeping the spokes from shifting. This means that when you break a spoke, you need to replace the whole length. To do so, you need the spoke, the requisite Mavic spoke wrench, and you need to loosen a third spoke a bit to get it into place. Not that this should be much of a concern. It’s hard to break these spokes and it’s hard to knock the wheels out of true.

Mavic Cosmic Carbone SLR/SRThe big question is whether or not these wheels are fast. Mavic’s R-Sys spokes aren’t fast (but they are stiff), Mavic’s Ksyrium Zicral spokes aren’t particularly fast (but they are strong). The Cosmic Carbone Ultimate spokes are fast. These, thankfully, are what the CC SLR spokes are based on, only you can true them.

The rim fairing makes the rims 52mm deep, which is an in-between depth these days. It’s halfway between the pack of 38-46mm deep rims and the pack of 58-66mm deep rims. Spokes are 4.95mm deep by 1.25mm thick. The spokes, for a stronger bracing angle, slot through sizeable cutouts on the sides of the fairing, rather than entering through the narrowest point of the fairing’s V shape. Obviously, the fairing will take on water and dirt, though water will drain out a small drain hole on the side of the fairing.

Our wheels came with a set of Mavic K10 tires on them. Thai made, they’re light at 220g per tire, and have both a rubber compound made to last and a breaker fabric under the tread for lightweight flat protection.

Rolling out the door, the wheels feel moderately fast. You get the extra noise thanks to the fairing, but between the low spoke count and the typically smooth Mavic bearings, the wheel feels good. Riding over rough pavement, the wheel feels solid. Stiff even.

Mavic Cosmic Carbone SLR/SRWe tried them out on our regular testing ground, a rolling 10k loop. On an almost-still, warm, summer day, the wheels helped us clock a lap of 4.17 w/kg at 15:24, which is pretty swift for the course. Not a perfect measure, as we didn’t go back and ride our training wheels for comparison immediately upon finishing. In flat and rolling races, where all the hills were climbed quickly in the big ring, nothing less than 18mph, the wheels felt super, slippery to wind and a friend of long breakaways.

The idea of racing long, steep climbs on these wheels is, we believe, not in the Cosmic Carbone SLR’s brief. All the same, we tried them out on the kind of hills where the wheels could penalize us. On a 1.5-mile climb where most of the final half-mile is a 14% grade, the wheels definitely slowed us down, particularly when compared to our friend on a set of R-Sys. We weighed the wheels at 760g for the front wheel and 910g for the rear, 1670g for the set, so the climbing experiment confirmed what we expected (the 2011 SR wheel set is supposed to be 725g front, 885 rear, don’t know if their weight is with or without rim strips; ours is with). All the same, for the punishment we felt on the steep hills, we returned the favor on the flats.

Mavic Cosmic Carbone SLR/SRWe also did some unexpected crash testing. One race, we were riding on a road that had been dampened by a light overnight drizzle and the humid air prevented the road moisture from evaporating. It had been the first rain in weeks and we attacked the course as if it was dry. Confident in our cornering abilities, we went into a sweeping turn at a speed we thought was safe. It wasn’t. It was the classic sparks-on-the road bike slide. While this kind of crash shouldn’t affect the wheels, we’ve seen odd things happen when a bike gets away from a person. The only damage was some wear on the rear quick-release lever.

Mavic Cosmic Carbone SLR/SRA couple of other notes on the wheels. We expected to find a traditional yellow Mavic rim strip covering the spoke holes. Our wheels came with a much-thinner black rim strip. This was a running change on the wheels. The thinner strip is lighter and makes it easier to mount and remove tires. We used a Mavic spoke magnet with the wheels, which comes with the set. This is their standard spoke magnet, and one of the few that fits, though you need to remove two tiny tabs from the plastic body holding the magnet in order for the body to be successfully locked onto place by the included set screw. Everything else you’ll need for working on these wheels comes with: valve extenders, spoke holder, spoke wrench, bearing tool, wheel bags, and their popular BR601 quick releases.

After a bunch of months on these wheels, with no problems whatsoever, and the wheels as true as the day we put them on our bike, we’re impressed. They definitely aren’t light, but they are fast and durable. A tubular version, which sponsored teams have access to, is probably a good bit lighter and rides even better. And taking a look at the expanded aero offerings from Mavic, including their 80mm deep carbon wheels, we have to revise our concern that they don’t offer much to a team like Garmin or Liquigas. Yes, Mavic wheels are firmly on the solid side of solid performance, but the performance is pretty impressive.