The Plews EN1 Grand Prix Spec B 140/80-18 15mm Rear Tyre combines an all-new 2026 soft compound, UK-designed carcass and increased tread depth for maximum off-road traction. ECE approved but not FIM or ACU time-card legal, it is designed for enduro, technical trail riding and hard enduro conditions.
$215.00
Plews EN1 Grand Prix Spec B 140/80-18 15mm Rear Tyre
The Plews EN1 Grand Prix Spec B 140/80-18 15mm Rear Tyre is the high-tread 2026 evolution of Plews’ EN1 enduro platform. Developed for riders who want increased traction without being restricted by the 13mm FIM and ACU time-card tread limit, it combines a 15mm tread depth with a soft wet-grip compound and next-generation UK-designed carcass.
Designed for enduro, technical trail riding, green laning, hard enduro training and off-road racing outside FIM or ACU time-card regulations, the Spec B delivers dependable grip across mud, soft terrain, rocks, roots and changing trail conditions.
Key Benefits
• 140/80-18 full-size enduro rear tyre
• Increased 15mm high-traction tread depth
• All-new 2026 soft performance compound
• Developed for wet, cold and technical conditions
• Next-generation UK-designed carcass construction
• Improved footprint stability and rider feedback
• CCRC compound technology helps resist chipping and chunking
• CCT tread technology helps reduce premature block damage
• ECE approved for road use where recognised
• Not ACU or FIM time-card legal
15mm High-Traction Tread
The EN1 Grand Prix Spec B uses a 15mm tread depth rather than the 13mm tread required for FIM and ACU time-card competition. The additional tread height provides increased bite in mud, soft ground, loose climbs and technical terrain where maximum traction matters more than race homologation.
The taller tread blocks are designed to dig into loose surfaces while maintaining control across rocks, roots and mixed trails. This makes the Spec B a versatile option for riders who encounter changing terrain during the same ride.
Plews identifies the Spec B as the world’s first FIM-style 140/80-18 enduro pattern engineered with an increased tread depth. It retains the familiar proportions of an enduro competition tyre while delivering the additional bite requested by riders who are not limited by FIM or ACU tread regulations.
2026 Soft Performance Compound
The all-new 2026 soft performance compound has been developed to improve wet grip, cold-condition traction and all-round off-road performance while maintaining dependable durability.
Its softer construction helps the tyre conform to rocks, roots and uneven terrain, allowing more tread to remain in contact with the ground. This improves drive traction and control in conditions where harder compounds can struggle to find grip.
Next-Generation UK-Designed Carcass
Developed in the United Kingdom under Plews Technical Director Ashley Vowles, the next-generation carcass is engineered to improve footprint stability, impact absorption, traction and rider feedback under aggressive riding loads.
The carcass works with the soft compound and 15mm tread to provide a controlled contact patch across technical terrain. This helps the tyre remain predictable under acceleration, braking and side loads while absorbing impacts from rocks, roots and sharp trail edges.
CCRC Compound Technology
Plews Compound Chipping and Chunking Resistant technology is a compound design approach developed to reduce tread-block chipping, chunking and premature damage. It aims to balance soft-compound traction with the durability required for repeated off-road use.
CCT Tread Technology
Plews Chipping and Chunking Tread technology uses a specialised tread design intended to reduce premature block tearing while maintaining traction and control across varied terrain. The tread geometry is engineered to support comfort, grip and dependable wear under demanding riding conditions.
Ideal For
• Enduro riding
• Green laning
• Technical trail riding
• Hard enduro training and racing
• Play riding
• Mud and soft terrain
• Rocks, roots and technical climbs
• Riders not restricted by FIM or ACU tread-depth regulations
Homologation & Competition Use
The Plews EN1 Grand Prix Spec B is ECE approved for road use where that approval is recognised. Australian riders should confirm the applicable road-registration and tyre requirements in their state or territory before road use.
Because the Spec B uses a 15mm tread depth, it is not legal for ACU or FIM time-card events restricted to a maximum 13mm tread depth. Riders competing under those regulations should select the compliant EN1 Grand Prix version instead.
Fitment
• Position: Rear
• Tyre size: 140/80-18
• Tread depth: 15mm
• Pattern: EN1 Grand Prix Spec B
• Generation: 2026
• Approval: ECE approved
• FIM/ACU time-card legal: No
Frequently Asked Questions
Is the Plews EN1 Grand Prix Spec B FIM legal?
No. Its 15mm tread depth exceeds the 13mm limit used for FIM and ACU time-card enduro events.
What terrain is the EN1 Grand Prix Spec B designed for?
It is designed for a broad range of off-road conditions, including mud, soft ground, rocks, roots, technical trails and hard enduro terrain.
Is the Plews EN1 Grand Prix Spec B road approved?
It carries ECE approval for road use where recognised. Check the applicable registration and road-use requirements in your Australian state or territory.
Why This Product?
The Plews EN1 Grand Prix Spec B 140/80-18 15mm Rear Tyre combines a soft 2026 wet-grip compound, UK-designed carcass and increased tread depth to deliver maximum traction across demanding terrain. It is built for riders who want the versatility of an enduro-style pattern with more bite than a race-restricted 13mm tyre can provide.
