Product Details
The Riaction GT1 Coilovers for the 1989-2001 Mercedes-Benz SL-Class R129 deliver a premium, adjustable suspension upgrade built for drivers who want more from their SL-Class R129 than the factory setup can offer. These Mercedes-Benz SL-Class coilovers are engineered to pair street comfort with canyon and track capability, giving you the stance, handling, and adjustability you've been chasing without compromising daily driveability. Whether you track your R129 SL-Class on weekends or log daily miles, this R129 coilover kit dials in ride height and damping to match how you actually use the car.
Every GT1 set features a monotube damper with 32 levels of damping adjustment, so you can tune ride quality to match the road, the weather, or your driving mood. Full-length ride-height adjustment separates preload from ride height — meaning you can drop the SL-Class R129 to the height you want while preserving spring travel and shock stroke. Riaction coilovers for the 1989-2001 Mercedes-Benz SL-Class are fully rebuildable and backed by a 2-year warranty, making the GT1 a long-term suspension investment rather than a disposable upgrade.
GT1 Series Technology
- Monotube linear damper with seamless 52mm electroplated carbon steel body
- 32-level damping adjustment (1-Way)
- 44mm CNC-machined 6061 aluminum high-flow piston
- 20mm piston rod for MacPherson applications / 14mm for non-MacPherson
- SAE9254 cold-wound linear main springs
- Multi-thickness valving shims for consistent damping
- Polyurethane oil seals and 7.5W suspension fluid
- Low-gas-pressure design for improved compliance
- Fully rebuildable — built to be serviced, not replaced
Features
- Full-length ride-height adjustment (preload-independent)
- 32 levels of damping adjustment
- Optional Swift Springs upgrade (sold separately)
- 2-year limited warranty
Specifications
| Part Number | MZ-021-SS |
| Part Name | Riaction GT1 Coilovers |
| Vehicle | 1989-2001 Mercedes-Benz SL-Class |
| Chassis Code | R129 |
| Adjustment Type | 1-Way |
| Ride-Height Adjustable | Yes |
| Spring Rate - Front | 20 Kg/mm |
| Spring Rate - Rear | 14 Kg/mm |
| Top Mounts - Front | OEM |
| Top Mounts - Rear | OEM |
| Camber Plates - Front | No |
| Camber Plates - Rear | No |
| Suspension Design - Front | True Coilover |
| Suspension Design - Rear |
Vehicle Fitment
- 1989 Mercedes-Benz SL-Class (R129)
- 1990 Mercedes-Benz SL-Class (R129)
- 1991 Mercedes-Benz SL-Class (R129)
- 1992 Mercedes-Benz SL-Class (R129)
- 1993 Mercedes-Benz SL-Class (R129)
- 1994 Mercedes-Benz SL-Class (R129)
- 1995 Mercedes-Benz SL-Class (R129)
- 1996 Mercedes-Benz SL-Class (R129)
- 1997 Mercedes-Benz SL-Class (R129)
- 1998 Mercedes-Benz SL-Class (R129)
- 1999 Mercedes-Benz SL-Class (R129)
- 2000 Mercedes-Benz SL-Class (R129)
- 2001 Mercedes-Benz SL-Class (R129)