Sunday, January 3, 2016

Mavic Cosmic Carbon 40 Elite wheelset review

I felt I needed to give these wheels at least 4 months of solid use in all conditions to be able to give an honest review. Full carbon clinchers have always had a shaky reputation with regards to heat buildup generated by braking. If you were to drag the brakes long and hard enough sometimes the heat buildup would affect the carbon and resin mix and cause serious braking issues, so my curiosity was really centered on braking in various conditions. I have to honestly say I was blown away by how by good braking was, in fact it was noticeably better than my Kysrium elite alloy wheelset. Carbon wheelsets have improved dramatically in recent years but how Mavic accomplished the braking issue is by using an alloy extrusion wrapped with a carbon fiber shell and injected the cavity with foam. In simple terms the alloy under the carbon surface acts like a heat sink pulling heat away from the carbon brake surface. Aluminum is better at dissipating heat than carbon and Mavic felt this was the best approach. The alloy core also adds to strengthening the structure of the rim which can help keep the rim true. Mavic finished the brake track with what it calls TgMAX technology, and claims the Tg point (glass transition temperature is the point at which the resin gets hot enough to revert to its liquid state) is able to exceed 250°C. On steep descents the brakes never faded and braking modulation was good, and surprisingly in damp conditions the brakes remained very solid and predictable though not as good as in the dry but all brakes fade somewhat in the wet. The wheels are 40mm deep and a 19mm wide bed. I'm using the 23mm Mavic tires that came on the wheelset. I haven’t hopped on the 25mm tire bandwagon, the 127 TPI - 23mm tires provide a great ride and when riders are so concerned about saving grams why add 12 to 18 percent more rotating weight in tires. In my opinion wider tires are hype in general conditions. I've ridden in some crazy winds with these wheels and never experienced any ill handling issues. The wheels weigh in 1545 grams a set, spin up fast compared to many deep wheelsets and I never felt any flex while sprinting. They track very precise and stable no matter how aggressive I ride. The brake pads are yellow Mavic pads apparently made by Swiss stop. The pads do leave some yellow residue on the braking surface but seemed to disappear after some miles. After 50 miles I did true the wheels slightly not because they became so untrue but because I can be a little OCD with things like that. The wheels were approx. 1.5 mm out of true so I tweaked them and since then their spot on after some serious thrashing. They come with all the necessary tools to true them and adjust the bearings. All the Mavic wheelsets i've had over the years have been totally bombproof and these are no exception. It's nice to have a durable fairly light deep carbon wheelset that you can leave on all the time.

The wheelset comes with Mavic Yksion pro tires. The rear is called
"powerlink" for better wear and the front is "griplink"
for increased grip. So far their great and the wear on the
rear is better than some other leading brands I've used. 

I  was truly surprised by how good the braking was.
Even in the damp the reduction in braking was minimal.


Yellow carbon specific pads leaves a little yellow
residue on the braking surface but it dulls out eventually