Patent ID: 7216861

Claim:
In an adjustable shock absorber having an inner cylinder with a first length L 1 and an outer threaded diameter with a maximum diameter d 1 , the inner threaded cylinder being surrounded by a coil spring having a second length L 2 and an inner diameter d 2 which is greater than d 1 whose compressive force is adjustable, the improvement comprising a protective cylindrical sleeve surrounding the inner cylinder inside of the coil spring, said protective sleeve having a cylindrical body portion of a third length L 3 substantially equal to L 1 and an outer diameter d 3 which is less than d 2 , inner diameter d 4 of said protective sleeve exceeding said maximum diameter d 1 of said threads to avoid contact therewith, whereby the outer surface or the inner cylinder is protected from rubbing-induced wear caused by the coil spring.