Improving the performance of damping rod forks

YSS PD Fork Valves

A common problem with bikes that have damping rod forks instead of cartridge forks is that the damping can be too harsh, or too easy to bottom out. In the past, this could have been addressed by changing the weight of the fork oil, or adapting the size of the holes in the damper rod that the oil passes through. The drawback of this method is that, quite often, the quantity of oil passing through isn't controlled enough and either too much or too little oil passes through – a bit of a black art, and very hit and miss with results - not an effective solution to damping issues.

PD Fork Valves — The better solution

PD Fork Valves are the cost-effective solution to this problem. Fitted at the top of the damping rods and held in place with the main springs, PD fork valves control the way the oil is distributed, so that the forks emulate cartridge forks, thus increasing their performance. They offer better control with a progressive feeling, better steering response and a more comfortable ride.

How PD Fork Valves work

The key to the effectiveness of PD fork valves is in their unique and innovative design. Once installed, they change the shape of the damping curve so that the oil is passed in a more controlled way. Low oil viscosity passes through more quickly, providing more damping; and high oil viscosity passes through more slowly, providing less damping.

PD fork valves take the control of compression damping away from the damping rod; once fitted, it will be controlled by the spring preload you set on the valve. They don't make a difference to rebound damping though this can be managed with the oil, which will provide more or less rebound depending on its viscosity.

Where can I buy PD Fork Valves?

Wemoto stocks YSS PD fork valves, which come in six sizes, suitable for a wide range of applications. YSS provides a full two-year warranty on all its products, for added reassurance.

Shop the full range of YSS PD Fork Valves