Ranger Point Precision

RPP Moto C4 Damping Rod Fork Suspension Upgrade Kit

  • Sale
  • Regular price $900.00
Tax included.

Transform your Honda NC750x, NC700x, CB500x motorcycle into an affordable, lightweight adventure sport vehicle superstar. With the full ability to tune both compression and rebound, your damping rod forks can perform as well as highly-tuned cartridge forks. 

C4 Suspension Kit for Damping Rod Forks: Tune for Confidence, Comfort, Control, and Contact. 

The first and only one of its kind, our kit employs patent pending technology to transform damping rods into cartridge style units with fully tunable, velocity sensitive compression and rebound valves. What’s more, these masterfully engineered damping valves, once installed, are serviceable from the top of the fork tube, allowing even novice mechanics to make adjustments to every damping aspect in just minutes. 

  • Dramatically improves compression and rebound damping control to rival cartridge style forks
  • Kits are pre-tuned per customer spec
  • Fully tunable without major disassembly, allowing fine adjustments to every aspect of the damping curves
  • Precisely machined aluminum components reduce unsprung weight by 1 pound

Damping Rod Fork Suspension Kit includes:

- 2 precision machined damping rods for 41mm Showa forks

- 2 cartridge-style compression valves with shim stack

- 2 patent pending rebound valves

- 1 valve extraction tool

- 1 DIY rebound valve fine tuning tool

- 2 rear shock linkages for 1" extra travel

Installation instructions 

Suspension Kit RPP-tuned: Customers will receive a tuned valve kit based on their selected option. 

Fork Spring Rate Calculator

Damping Rods and Suspension: Limitations to Tuning, Compression and Rebound Damping

By the 1990s “cartridge” type front forks were already commonplace on many performance motorcycles. These dampers are self-contained units inside the fork that employ variable orifice, fully tunable valves to control all aspects of the damping curve.

But another, very old technology soldiered on in less expensive and less performance oriented motorcycles. “Damping rod” type forks employ crude, fixed orifice damping units that are incapable of adjusting to varying wheel speeds or terrain conditions. They are compromised. They are non-tunable. And they still soldier on today.

You can still find damping rods in many entry-to-mid-level sport bikes, naked bikes, and cruisers. The good news is that many of these otherwise great motorcycles are thousands of dollars cheaper than their competition oriented counterparts. Even better, there is finally an effective way to upgrade those old damping rods to cartridge level performance.

Transformative Suspension Blog Post

How it works: On the compression stroke, oil is forced upwards into the damping rods with four bleed holes, through the center of the rebound valve, and up through the two-way compression valve. The compression valve shims keep the ports covered, preventing aggressive dive under braking. At faster speeds, the compression valve shims bend open to blow off high pressure and soften harsh bumps, while preventing bottoming of the forks.

During the rebound stroke, oil flows out through a small hole in the rebound valve to maintain excellent pitch control during turn-in, braking, and terrain dips. At faster speeds, the rebound valve collar slowly opens until it’s blown open entirely, exposing a t-shaped port so the forks can extend rapidly and the wheel can quickly regain contact with the road.