The design of Zycle rollers is different from other brands. The weight of the cyclist and the bicycle rest completely on the roller, thus any wheel defects are transmitted directly to the seat and the ground, just the same as when you're on the road. The pedalling sensations are therefore better and more real than the sensations transmitted by other rollers. So it is relatively normal to feel a little vibration when using Zycle rollers.
If these small vibrations are bothersome, use a rubber mat or other vibration absorbing material.
If you think that the vibrations are excessive, please contact Zycle as soon as possible to provide a solution.