Mavic

Ksyrium Pro UST Wheel

The Ksyrium wheel from Mavic has a storied history. As the worthy successor to the Helium, arguably a wheelset that along with the Cosmic spawned the prebuilt wheel movement, it was catapulted to success by the pros in the grand tours and classics in the early aughts. Quite a bit has changed on the racing front since then, namely the move to carbon wheels. While the pros continue to race on tubulars, we don't always have the luxury of a team car following us, so we think the next best thing is tubeless. That's where the Ksyrium Pro UST Wheel shines, leveraging its tubeless know-how from way back in 1999 with its mountain bike going Crossmax wheelset, which coincidently coincided with the release of the original Ksyrium, the wheels combine the weight savings, flat reduction, and ride quality of tubeless.

The effect of Mavic's generation of tubeless genius becomes apparent early in the process of mounting the tires. We all love the lower rolling resistance, cushier ride, and increased puncture resistance of tubeless tires, but mounting them is an admitted hassle that's left a lot of us sticking with traditional tubes. Mavic's road UST design virtually eliminates any of these misgivings.

First, the tires mount without levers. Mavic recommends tire levers if you'd like, but, in our experience, the brand's UST tires pop on and off with bare hands as easily (or more easily than) most tires on most other competitor's rims. The ease of installation and removal alone make a compelling case that Mavic is once again the leader in road wheel reliability, but the ease of inflating the UST design removes all doubts.

Tricks for seating tubeless tires are often just that: tricks that involve a bit of luck for all but the most capable wrenches. Mavic turns this on its head: mounting UST tubeless tires to UST tubeless rims is less an art and more of a simple, easily reproducible act of science. Just pump them up. That's it. No CO2 cartridges, no fingers crossed moments to see if the air compressor will pop the beads into place, no disheartening bang from the tire burping over the rim. Just your trusty old floor pump and a bit of elbow grease.

The key to the ease of mounting and inflation is typical Mavic. It involves an obsessive R&D cycle that established tolerances to within a millimeter; a hair in either direction would mean the tire would either be nigh impossible to mount but virtually immune to burping or easy to mount with a tendency to roll off in corners. Traditionally, wheel and tire manufacturers have defaulted to the former for obvious reasons; however, Mavic didn't accept the trade-off, and the reason it took so long to join the road tubeless game is that it wasn't satisfied until it had addressed the most common critique of reliably safe tire/rim interfaces.

In addition to all the benefits of UST tubeless, these wheels come with the same features that make the non-UST, version of the Ksyrium Pro wheels a staple on neutral support vehicles in professional races. These include weight-reducing rim milling, lightweight aluminum spokes, and Mavic's new Instant Drive 360 freehub engagement. The weight reduction is telling. At just 1,410 claimed grams, the wheels without tires are a wopping 220 grams lighter than the non-tubeless Helium "climbing wheels" from 20 years ago. A deep dive into the freehub would warrant a few more column inches, but we'll spare you the details and summarize it as a system of dual-ratcheting rings that rivals the hubs typically featured on custom builds and vanity wheelsets.