QRS X-Series

The Quantum 4X is a modern gas pressurised recirculating shock absorber with in-line valve head. This permits independent adjustment of high and low-speed bump and rebound damping.

Every X series low-speed bleed adjuster has exactly eight positions defined by a “click” and a positive stop at max stiff and max soft. The eight positions correspond to eight drilled bleeds that are opened sequentially as the adjustment is made. Each drilled bleed can only ever be open or closed, offering an improvement in usability over traditional needle and jet adjusters that can be vague and often require several clicks of adjustment before a change can be felt through the seat of the pants.

X Series high-speed preload adjusters work by preloading four hard chrome ball bearings against valve seats cut into the piston. Each adjuster has two full turns of adjustment affecting the “digressive” part of the damping curve. Once the pressure behind the piston is sufficient to overcome the preload adjuster, the adjuster “blows” open and the rate at which damping force increases with velocity is significantly reduced.


  • Quantum X Series

    £4,090.40 + VAT