When disc brake technology started to appear on road wheels, it was natural for us to develop a compatible wheel based on our iconic Ksyrium Pro SL. But disc brakes also throw up a unique set of challenges, so it was a huge benefit to fall back on our experience designing mountain bike disc wheels. The end result is this do-it-all wheel that excels on most rides: flat or hilly, training or racing.
Brilliant brake torque
The biggest difference between the two braking systems is that braking with discs displaces the brake forces from the rim to hub, moving them further away from the ground. To make its way from the hub to the ground, the braking torque is distributed through the hub, spokes and finally the lower rim. So the spoke dimensions and lacing pattern needs to be tuned accordingly.
The braking load is higher on the front wheel since the center of gravity is transferred to the front of the wheel when the bike is decelerating. Thus, the front wheel needs to be overbuilt with more spokes (20 instead of 18) and those spokes need to be crossed on each side of the wheel to make sure the brake torque will be efficiently and evenly distributed.
The lower part of the rim also undergoes higher stress than a rim brake wheel. This stress is about the equivalent of the pedalling torque so what the rear rim can withstand in traction, it can also stand when braking. The front rim however, needs to be redesigned and gets the same dimension as the rear rim, also benefitting from asymmetrical design as the disc creates asymmetry in the wheel dish.
ISM4D: lower weight without compromise
Our unique ISM4D technology (Inter Spoke Milling 4 Dimensions) makes sure the rim weight is kept at a minimum for better agility and reactions when speeding up or braking. By only using material where it’s needed for stiffness or durability, we can achieve extremely low weight without making compromises elsewhere. As a result the Ksyrium Pro Disk is just 1535g – the best possible choice for any disc-brake-equipped road bike.
Matching Yksion Pro tyres
To make sure all this extra stopping power reaches the ground, Ksyrium Pro Disc comes with our Yksion Pro tyres in 25mm. They offer a supple 127 TPI casing, Kevlar beads, a well-balanced rubber compound that offers the best blend of grip and rolling resistance and a weight of only 190g in 23mm and 205g in 25mm.
The front wheel comes with the Griplink version that offers a specific tread pattern to evacuate water quickly when cornering, increasing confidence and speed in difficult conditions. It also offers very strong Kevlar puncture protection for added safety.
The rear wheel comes with the Powerlink version, which sports a more supple nylon puncture protection instead of Kevlar to lower rolling resistance. To reduce rolling resistance and increase speed even further, the tread pattern is optimized to reduce the pressure on the ground, while improving water evacuation from the center to increase traction and efficiency in wet conditions.
- Compatibility - Through axle with 6 Bolt disc fitment
- Weight : 1535 grams (Pair without tyre)