This listing includes a pair of DIAMOND+ 400mm Machined Shocks with Adjustable Reservoir for the Honda TRX 400EX, 450R & ER, 250R.
Also included: (2) 10mm coils.

We also offer extra-durable Delrin bushings in our eBay store!


Performance Engineered: Full 4-Way Adjustability

Precision-tuned for the serious rider. These Diamond+ Shocks are designed to be fully customizable to your vehicle's weight, your riding style, and the terrain.

⚠️ Fitment Note: These shocks include 10mm bushings by default. If you require 12mm or 13mm (Harley-Davidson) bushings, please include a note with your order to ensure correct fitment.

🛠️ Adjustable Length: Fine-tune your ride height by unscrewing the lower shock eye and setting the threading nut to your desired length.
🌀 Adjustable Preload: Dial in your sag using the included tool to tighten the collar above the spring coils.
📉 Compression Tuning: Control compression speed with precision. Use the included Allen wrench to adjust the inside silver knob on the top reservoir.
📈 Rebound Tuning: Manage the shock's return speed. Use the included Allen wrench to adjust the inside silver knob on the bottom reservoir.

Technical Specs: 400mm Spring Rates

This listing includes upgraded 10mm coils (standard for this shock is 9mm). Spring rate specifications are listed below for reference.

Coil / Kit Type Spring Rate Max Force (Per Shock)
400 x 9mm Coils 157 lbs/in 618 lbs
400 x 10mm Coils 222 lbs/in 873 lbs
400 x Dual-Rate Kit 200 lbs/in 630 lbs

Upgrade Your Experience: Delrin Bushings

For riders seeking maximum durability and tighter tolerances, we offer our Delrin Shock Bushing Upgrade. These are precision-machined to reduce play and extend the life of your mounting points. Available as an optional add-on during checkout.

Diamond J Customs Warranty:
Also included: (2) 10mm coils.

We stand behind our engineering. We will replace any shock components that fail within three months of purchase at no charge (limit one replacement per purchase).

*Note: Warranty does not cover normal wear and tear, improper installation, or misuse. Shocks installed at improper angles may increase bushing wear rates.

All sales subject to Diamond J Customs Terms of Sale.