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FAQ + live marketUpdated 2026-03-11
Nike ACG ACG Ultrafly Trail
Nike's pinnacle trail racing shoe with ZoomX foam and carbon plate delivers elite performance on moderate terrain, proven at the highest levels of ultrarunning but polarizing on technical trails.
Guide Score
87/100
ExcellentLensTrail
Comfort9/10
Durability6/10
SizingTrue to size
WidthStandard fit
Dress codeAthletic
CushioningZoomX
This is our 0-100 guide score for the shoe overall. Higher is better. It is not a stock number or a price score.
How to trust it
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Strong evidence — extensive community discussion
Key facts
- Popularity: Elite-level recognition after Western States 100 win
- Comfort: ZoomX delivers exceptional energy return and cushion
- Fit: Improved wider toebox over the original, generally TTS
- Value: Premium priced but justified for a carbon-plate trail racer
- Use case: Trail racing, ultra-distance events, fast trail runs
- Risk: Struggles on highly technical terrain, less grip than pure trail shoes
Shoe intelligence
Comfort 9/10Durability 6/10True to sizeZoomXHiking
Guide
Full breakdown
The Nike ACG Ultrafly Trail is a premium trail racing shoe featuring ZoomX foam cushioning, a split carbon fiber FlyPlate, and a Vibram Litebase outsole. Developed over 13 rounds of testing across 30,000+ miles, it won the 2025 Western States 100 on the feet of Caleb Olson. A wider toebox addresses complaints about the original Ultrafly. The Ultrafly 2 iterates with a refined last.
Questions answered
FAQ
Is the Nike ACG Ultrafly good for trail running?
It excels on moderate, runnable trails where you can maintain pace and open your stride. The ZoomX foam and carbon plate provide exceptional energy return. On highly technical terrain with rocks and roots, it becomes less stable and grip can falter.
How does the Ultrafly compare to the HOKA Tecton X?
Both are carbon-plated trail racers, but the Ultrafly has more aggressive energy return from ZoomX while the Tecton X offers a more balanced ride. The Ultrafly is faster on smooth trails, the Tecton X more versatile on mixed terrain.
Can you use the Ultrafly for daily trail training?
It is designed as a racing shoe and the ZoomX foam is not the most durable for daily training miles. Most runners use it for races and fast workouts, pairing it with a more durable daily trail trainer like the Nike Pegasus Trail.
What's the difference between the Ultrafly and Ultrafly 2?
The Ultrafly 2 features a refined last with a wider toebox, addressing the most common fit complaint about the original. The midsole formula and plate design are similar, with incremental improvements to the upper and outsole pattern.
Is the Ultrafly worth the premium price?
For serious trail racers, yes. The ZoomX foam and carbon plate deliver measurable performance benefits proven at elite competition levels. Casual trail runners are better served by less expensive options that prioritize durability over race-day speed.
Sources & methodology
This page mixes guide writing with current store data.
Editorial citations have not been backfilled for this guide yet.