Yamaha YZ450/250F Linkage System

Krooztune Yamaha YZ450/250 Linkage System

Linear Performance • Improved Chassis Balance • Rider-Focused Feel

Overview

The Krooztune Yamaha YZ450 Linkage System is designed to deliver a more linear, confidence-inspiring rear suspension action, without sacrificing stability or holdup where it matters.

While the OEM Yamaha linkage provides excellent peak holdup in aggressive scenarios, our linkage offers a smoother force curve and improved ride comfort through big bumps, making it ideal for Vet riders, juniors, and C–B grade racers seeking traction, control, and reduced fatigue.

This system focuses on usable travel, balanced chassis attitude, and predictable response, especially under acceleration and corner exit.

Key Design Philosophy

• More linear leverage ratio for a smoother, more controlled feel throughout the stroke
• Reduced harshness in square-edge and big bump impacts
• Improved chassis balance without compromising stability
• Designed to work with correct valving—not mask it

This linkage allows the shock to operate in a more consistent range, making suspension setup easier and more forgiving across a wide range of rider abilities.

Ride Characteristics Compared to OEM

OEM Yamaha Linkage Traits

• Excellent holdup in deep ruts and heavy seat-bounce scenarios
• Strong mid-to-end stroke resistance
• Can feel firm or abrupt for Vet, junior, or non-elite riders
• Tendency toward a low rear-end feeling, especially on corner exit

Krooztune Linkage Traits

• Much more linear action through the stroke
• Big bumps feel noticeably softer and less aggressive
• Improved traction and comfort under acceleration
• Allows a plusher feel without losing control
• More predictable behavior in technical sections and ruts

Geometry & Chassis Balance

• Pullrod Linkage is 0.6 mm shorter than OEM ( can use oem pullrod but wont address low end feeling and balance.
• Results in approximately 4–5 mm rear ride height increase
• Improves initial holdup while maintaining linear action

Benefits:

• Removes the YZ’s “low rear end” sensation
• Stronger corner-exit drive and stability
• Better balance front-to-rear without excessive preload
• Allows rebound to be slowed safely without fear of rear squat

This balance is especially noticeable for Vet riders and riders who prioritise traction and confidence over aggressive hit resistance.

Spring Rate Recommendation (Important)

Due to the increased linearity of the linkage:

Spring rate should be increased by one step

Example:

• OEM: 56 N/mm
• Krooztune linkage: 58 N/mm

This ensures correct ride height, improved holdup, and proper support through acceleration and braking zones.

Valving Compatibility

The linkage works well with OEM valving, but performs best when paired with correct shock tuning.

Recommended adjustments:

• Slight increase in low-speed compression for chassis support
• Slight increase in high-speed compression for holdup
• Rebound can be slowed slightly due to improved ride height and balance

This combination delivers a planted feel without harshness and dramatically improves control in ruts and technical sections.

Ride Height Options

• To retain OEM rear ride height, simply refit the OEM pull arm
• Allows flexibility depending on rider preference, track conditions, or setup goals

Ideal Rider Profile

• Vet racers
• Junior riders stepping into larger capacity bikes
• C–B grade racers
• Riders seeking comfort, traction, and consistency
• Anyone wanting to remove harshness without losing confidence

Summary

The Krooztune Yamaha YZ450/250 Linkage System is not about chasing peak stiffness—it’s about balance, feel, and usable performance.

✔ Linear, predictable suspension action
✔ Softer big-bump response
✔ Improved corner-exit traction
✔ Better chassis balance
✔ Designed to work with proper spring and valving setup

For best results, pair this linkage with correct spring rate and professional shock tuning.