Nike Men's ACG Ultrafly "Spruce Fog"

The Nike ACG Ultrafly builds on the success of its predecessor with a smoother, more refined ride for trail runners chasing speed over long distances. Designed for racing and high-performance training, it combines Nike's most advanced cushioning with trail-specific grip and a more compliant carbon plate to inspire confidence across technical terrain.

At the centre of the shoe is Nike's ultra-responsive ZoomX foam, delivering exceptional energy return while maintaining a stable platform for uneven trails. An updated heel construction leaves the foam exposed to increase responsiveness, creating softer landings without compromising control during long days in the mountains.

A full-length carbon-fibre plate sits within the midsole, tuned to be slightly more flexible than the original Ultrafly. This refined construction improves trail feel and adaptability across technical terrain while still delivering the efficient propulsion needed for racing and ultra-distance efforts.

The lightweight engineered mesh upper is designed to perform in changing conditions, offering excellent breathability while draining water quickly after river crossings and wet sections of trail. Underfoot, a Vibram® Megagrip outsole provides outstanding traction across wet rock, loose gravel and hard-packed trails, giving you the confidence to maintain speed when the terrain becomes more demanding.

Whether you're lining up for an ultra-distance race or tackling big days in the mountains, the Nike ACG Ultrafly is engineered to help you move efficiently from the first climb to the final descent.

• ZoomX Foam: Ultra-responsive ZoomX foam midsole delivers Nike's highest energy return with a stable feel for the trail. The foam is 'unwrapped' in the heel for even better responsiveness.
• Breathable Mesh Upper: Don't worry about puddles or streams—the upper is made for water drainage. It's also lightweight, durable and breathable.
• More Flexibility: Tackle technical terrain with the full-length carbon-fibre plate. We reduced the stiffness compared to the original Ultrafly for better control on the trails.
• Enhanced Grip: Go the distance with Vibram® Megagrip outsole. It's designed to give you durability and enhanced grip on wet terrain.
• Colourway: Spruce Fog/Black Spruce-Sea Glass
• Product Code: HF5668-300

Technical Specifications:
Intended Use: Trail Running / Trail Racing
Support: Neutral
Width: Regular
Weight: Approx 290g 
Drop: 8.5mm (37mm heel vs 28.5mm toe)
Lug Depth: 3mm

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