In the late 1980s, when mountain biking was defining its ideal routes, the Radical was first introduced. For years, it remained a top performer and market leader, retaining its position well into the 1990s. Decades passed, and the Radical seemed destined for the dustbin of history. However, Sunn has reignited interest in the model for 2025 by faithful recreation of the classic design and, somewhat surprisingly, incorporating mixed frame features.
The new suspension platform is a development of the technology from the Noster Kinetics, which was initially designed for downhill bikes, as stated on the Antidote website, where it explicitly says the Noster Kinetics system is suitable for downhill bikes only. I can only assume that this design has been modified for the Radical bike to make it more pedal-friendly, considering its capabilities for climbing and its appeal to enduro racers.
The Radical bike’s design features a split-pivot linkage setup with an idler pulley, typical of high-performance bikes in 2025. The rear axle path is placed towards the back for improved stability on rough terrain and absorption of impacts. For more information on the Noster Kinetics system, Antidote has some limited documentation available, providing a deeper dive into the technology.
I’m still trying to wrap my head around the Radical bike’s unusual design choice. Despite being marketed towards enduro racers and riders, this bike’s design seems counterintuitive for that purpose. According to the manufacturer, Sunn aims to build this bike for fast, hard downhill riding, but it appears to be less equipped for carrying heavy enduro loads, particularly the transfer sections between climbs and descents. Sunn proudly proclaims on their website: “We have developed kinematics closer to that of a DH bike than to that of an All-Mountain bike,” which implies an intense focus on downhill performance. However, a surprising omission on the Radial is the lack of bottle cage bosses, even though the frame seems large enough to accommodate them.
While the extension rod utilized by the Noster doesn’t disappoint in terms of climbing capability, it doesn’t exactly excel either. However, I suspect the variably angle-adjusted pivot points and linkage in the Radical’s design may hinder its climbing performance, particularly compared to its advertising claims. Furthermore, not including a water bottle cage is a glaring oversight that really bugs me.
The Radical comes in three models, each offering 170mm of front suspension travel and 160mm in the back. The model names are somewhat unclear, but they are Factory, Finest, and S1. The Factory has a high-end setup with Fox Factory components, SRAM’s premium transmission, and TRP’s DH-R brakes. The Finest build features Fox suspension, but a GX mechanical drivetrain and Formula’s Cura 4 brakes. The S1 model is the only one with RockShox suspension, Shimano drivetrain, and Formula Cura 2 brakes. The Radical is currently available in Europe, and pricing details will be disclosed.
Discover the bold and innovative products in the Radical line at Sunn.fr!
Builds & Pricing
Radical Factory
Manufacturer’s Suggested Retail Price: $7,434.55 USD
- Fork: Fox Racing Factory Fork
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The Fox Float X2 Factory Fork is nothing short of remarkable. A cutting-edge suspension solution, its technology is rooted in innovative engineering. Named after the renowned traction management system used in motocross and enduro racing, the X2 delivers uncompromising performance. Here’s why:
1. Efficiency Optimized Tuning: Its series damper is tweaked to offer the ultimate versatility, capable of adapting to varying riding styles and terrain.
2. Air Spring and Compression Damping: The X2’s air spring system offers the perfect balance of rigidity and absorbency, providing exceptional traction and a seamless ride.
3. Multistage Compression, Multistage Rebound: Adjustable options for both compression and rebound offer riders finesse control over their ride, tackling whatever trails they encounter.
4. Customizable Accents: Choose from a range of my colours, allowing you to create a one-of-a-kind appearance.
5. Weight-Optimized Design: A narrower overall profile minimizes weight and enhances tire clearance.
The X2 Factory Fork not only raises the bar, it redefines the standard. vysoké - The drivetrain used is a Sram Xo Eagle Axs T-Type setup.
- Wheels: Dt Swiss Ex1700
- Dropper: Fox Transfer Factory
- Brakes: TRP DH-R EVO
Radical Finest
Manufacturer’s Suggested Retail Price: $5,954.40 approximately
- Fork: Fox 38 Factory Series
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Flexibility and speed aren’t mutually exclusive. One fork positioned next to another, confident in effortless bashing out switchback trails.
It features:
• Length: 1660mm
• Offset: 44mm
• Inner bearing design
• ID350 Clamps - Drivetrain: SRAM GX 12-speed
- Wheels: Dt Swiss E1900
- Dropper: Brute Dropper
- Brakes: Formula Cura 4
Radical S1
Manufacturer’s Suggested Retail Price: Approximately 4,032 Euros, equivalent to approximately 4,262.81 US Dollars.
- Fork: Rockshox Zeb, Debonair+
- Shock: RockShox Super Deluxe Select
- Drivetrain: Shimano XT 12-speed
- Wheels: E-Thirteen LG1+ 29’
- Dropper: Brute Dropper
- Brakes: Formula Cura 2
