Rear Cushions

Rear Cushions

Shock absorbers consists of spring which determine posture and cushioning buffer action and a damper which suppresses vibration.
On 2-wheeled vehicles, shock absorbers are separated into the categories of the “front fork” and “rear cushion”.
The rear cushion:

  • Maintains posture of the vehicle.
  • It eases the thrust of shocks on rough roads.
  • The rear cushion prevents changes in the contact forces between the rear tires and the road surface, conveys the driving power from the rear tire smoothly to the surface of the road, and creates conditions that conduce excellent traction as it maintains the power of the vehicle and damping capacity.
Technical illustration of motorcycle rear cushions

SHOWA's Approach

SHOWA develops its technology for stock motorcycles based upon feedback gathered from data for 2-wheeled vehicle road races and motocross races.

Thanks to recent improvements in dynamic performance, the gripping power of the tires, improvements in the efficiency of the brake system, the increased control of sudden frontal subduction when breaking, as well as increased absorbency of road surface gaps along with a compatible riding comfort, SHOWA has been able to develop its B.P.F. forks for road models. By striving to achieve further improvements to the rear cushion and in tire traction, we have also succeeded in installing the B.F.R. system in bikes for road racing as we aim for mass production.
With the large diameter front forks used in off-road models, and with regard to the weight trends of highly rigidity, we have been able to achieve significant weight reductions in our S.F.F. construction designed to enter the mass market. Through feedback from stock models utilizing performance and functional improvements cultivated from the limits of racing, SHOWA aims to provide shock absorbs that have achieved:

  • A high level of driving safety
  • Exceptional riding comfort
  • Weight reductions

Furthermore, in light of our anticipations for increased future sales expansion in the Asian market, and in order to be able to provide ever more attractive products for our users, we are opening a new R&D facility in Thailand that is to serve as our Asian base. We feel that have been able to prepare an extremely timely development system.

Double tube type


Picture of a double tube rear cushion

Constructed with double tubes, in side is an oil chamber and outside is an air chamber . Have types with low pressurization to obtain further stable damping. Applied from small commuters to large-sized cruisers.

Technical Illustration of a double tube rear cushion

Double tube type Details

  • Double-tubed construction with a tube and cylinder.
  • Design freedom is extremely high in order to avoid subjection the oil seal to high pressure.

Single tube type

Pressurized type (single tube type)

Picture of a Pressurized type (single tube type) rear cushion

Demonstrate high performance due to construction of separate oil and air chambers. In some smaller vehicles, partitions are not applied ( emulsion type ). Applied to wide range of models.

Technical illustration of a Pressurized type (single tube type) rear cushion

Single tube type Details

  • The inner wall of the tube serves as the cylinder.
  • Excellent responsiveness makes it possible to enlarge the size of the piston valve.
  • Superb heat dissipation.
  • Structurally the mounting angle has no limits. (It can even be used upside down.)

With pressurizing sub-tank

Picture of a Pressurized rear cushion with sub-tank

Basically similar with a singe tube construction, however excellent in heat dissipation.
This type have wide range of settings.