PURE Racing TRX Rear Shock | Surron Ultra Bee

The PURE Racing TRX 673A rear shock brings precise damping control, improved traction, and stronger impact management to the Surron Ultra Bee. It installs directly in the stock location and includes a rider-selected coil spring, making it a serious suspension upgrade for trail riding, motocross tracks, and harder off-road use.

PURE Racing built the TRX around a dual parallel oil system with separate, easy-to-reach compression and rebound controls. Both adjustments offer 19 clicks, giving riders a useful tuning range without making setup unnecessarily complicated. The blue adjuster controls compression damping, while the red adjuster controls rebound damping.

Trail and MX Tuning Options

Trail tune: Controlled, supportive, and comfortable for most riders. This setup helps the Ultra Bee maintain traction over rocks, roots, braking bumps, and uneven terrain while reducing harsh feedback through the chassis.

MX tune: A stiffer, more responsive tune designed to provide additional feedback and absorb larger impacts. It is the better choice for aggressive riders, jumps, faster track riding, and repeated hard hits.

Recommended Balanced Suspension Pairings

• Trail setup: TRAXION Trail 960N fork paired with the TRX Trail shock and a 500 lb coil spring.
• MX setup: TRAXION MX 1420N fork paired with the TRX MX shock and a 580 lb coil spring.

TRX Construction and Performance

Inside the TRX are 3D-printed waffle pistons positioned in the upper and lower chambers of the internal cartridges. These pistons support the compression and rebound circuits, helping the shock deliver a progressive, quiet, and controlled damping response.

Precision-honed inner cylinders are manufactured to a tolerance of ±0.01 mm. That level of accuracy reduces unwanted friction, promotes smooth damping movement, and helps the rear tire follow the ground more consistently when traction matters most.

Custom oil and dust seals balance dependable sealing with low operating friction. This supports consistent oil flow through tens of thousands of suspension cycles. Advanced fluid dynamics further refine the damping response, while the link plate structure has been enhanced through FEM analysis for rigidity, fatigue resistance, and weight-efficient strength.

Five-axis CNC-machined construction adds the precision and durability expected from a performance-focused Ultra Bee suspension component.

Technical Specifications

• Name: TRX 673A
• Damper: Dual parallel oil system
• Compression adjustment: 19-stage adjustable, blue control
• Rebound adjustment: 19-stage adjustable, red control
• Selectable spring weights: 500 lb, 540 lb, 570 lb, and 630 lb
• Available tuning: Trail or MX
• Weight: 3.1 kg

Fitment

• Surron Ultra Bee
• Direct replacement for the stock rear shock
• Uses the original Ultra Bee linkage plates and bolts
• No additional installation parts are required

What Is Included

• PURE Racing TRX 673A rear shock
• Coil spring in the selected weight

Who This Shock Is For

• Trail riders looking for better comfort, support, and rear-wheel traction on rough terrain.
• MX and aggressive off-road riders who need firmer feedback and improved control through larger impacts.
• Performance-focused Ultra Bee owners who want adjustable compression and rebound damping with direct stock-location fitment.

The TRX 673A stands out through its precise internal construction, independently adjustable damping, and purpose-built Trail and MX tunes. For riders pushing the Surron Ultra Bee beyond casual use, it provides the tuning range and impact control needed to build a more balanced, predictable suspension setup.