- Black springs - Black body - S: Single tube body - Piston diameter: 36mm - D: Monotube high pressure gas type shock absorber with internal reservoir in the main body - Length: 279 mm - Stroke: 42 mm - Rate N/mm: 26 N/mm - Position: rear - Packaging unit: pair - ABE approved. The STX36 is a shock that's been around the block and it paid it's dues when it comes to performance and durability. Especially for the cruiser market when taking riding a step up, the STX36 is an excellent investment when suspension characteristics are important to you.