ShoeGeometry

Nike ACG Ultrafly Trail

TrailTrailCarbon plate2026Men'sCurrent

At a glance

Heel-to-toe drop
8.5 mmStated
Stack, heel / forefoot
38 / 29.5 mmStated
Weight
267 gStated
Plate
Carbon plate
Toe rocker
36 % of lengthest.photos 34–37 %
Heel bevel
9.1 % of lengthest.rough estimate; photos 9–10 %
Stiffness / firmness
46 / 42 of 100Derived
Primary foam
ZoomX (dual density)

How it compares

  • Nike ACG Ultrafly Trail's heel-to-toe drop is 8.5 mm, higher than the catalogue median of 6 mm (89% of the 179 other current shoes are lower).
  • Nike ACG Ultrafly Trail's heel stack is 38 mm, about the catalogue median of 38 mm (43% of the 176 other current shoes are thinner).
  • Nike ACG Ultrafly Trail's forefoot stack is 29.5 mm, thinner than the catalogue median of 31.5 mm (32% of the 171 other current shoes are thinner).
  • Nike ACG Ultrafly Trail's weight is 267 g, about the catalogue median of 269 g (49% of the 167 other current shoes are lighter).
  • 4 shoes with similar geometry from other lines.

Differences smaller than the precision of the sources (about 1 mm of stack, 8 g, or the spread between photos for photo estimates) are reported as about the same.

Specifications

Heel-to-toe drop
Manufacturer stated
8.5mm
HighSpec listingsource
Heel stack
Manufacturer stated
38mm
MediumSpec listingbrand figure, reported by Running Warehousesource
Forefoot stack
Manufacturer stated
29.5mm
MediumSpec listingbrand figure, reported by Running Warehousesource
Weight
Manufacturer stated
267g
MediumSpec listingbrand figure, reported by iRunFarsource
Plate
Carbon plate
Primary foam
ZoomX (dual density)
List price
$260

Plate, foam and price from Nike ACG Ultrafly Trail Trail Racing Shoes. Nike.com.

Geometry

Catalogue average: heel 38 mm, forefoot 32 mm, toe rocker 34 %Nike ACG Ultrafly Trail: heel 38 mm, forefoot 30 mm (drop 9 mm); toe rocker 36 % of length, radius 57 % of length; heel bevel 9 % of length, 16 mm high at the back, ending behind the heel bone (only the back edge is rounded).38 mm30 mmUnder the centre of the heel bone: 12 % of length from the heel, where heel stack is measuredheel boneHeel contact: the sole is within 4.5 mm of the ground from 9 % of length (foam compresses more under load), ending behind the heel bone (only the back edge is rounded)heel bevel 9 %Toe rocker: the front 36 % of the length curves up (the curve leaves the ground 64 % of length from the heel)toe rocker 36 %toeheel
Front: toe rocker shorter longerRear: heel stack lower higher not measured
Dashed: average of the catalogue
Illustrative profile, not a photograph or scan: drawn to scale for a 300 mm shoe from published stack heights and photo estimates of the unloaded shoe (under body weight the foam compresses and the curves flatten). The grey upper is a generic outline, not this shoe’s. Nike ACG Ultrafly Trail: heel 38 mm, forefoot 30 mm (drop 9 mm); toe rocker 36 % of length, radius 57 % of length; heel bevel 9 % of length, 16 mm high at the back, ending behind the heel bone (only the back edge is rounded). Heel bone: 12 % of length from the heel, where heel stack is measured. Heel bevel and toe rocker are marked where each curve meets the ground; for the heel that is where the sole comes within 4.5 mm of the ground, which foam compression closes under body weight.

Percent values are relative to shoe length so they compare across images and sizes; widths in millimetres are lab measurements from the cited source, while toe tip and heel heights in millimetres are photo estimates converted for a men’s US 9 (assumed 300 mm long), so approximate. See how rocker geometry is defined.

Toe rocker
AI estimated
36%

4 photos range 34–37 %; shown is their median.

LowSide photosource
Rocker radius
AI estimated
57%

4 photos range 48–57 %; shown is one of the two that agree most closely.

LowSide photosource
Rocker rise angle
AI estimated
25deg

4 photos range 23–26 deg; shown is their median.

LowSide photosource
Toe tip over ground
AI estimated
34mm

4 photos range 33–34 mm; shown is their median.

LowSide photosource
Rocker angle at toe
AI estimated
58deg

4 photos range 55–58 deg; shown is one of the two that agree most closely.

LowSide photosource
Visible rocker lift onset
AI estimated
77.4%

4 photos range 75–77.4 %; shown is one of the two that agree most closely.

LowSide photosource
Toe spring (relative)
AI estimated
16.4%

4 photos range 15.8–16.6 %; shown is their median.

LowSide photosource
Heel bevel length
AI estimated
9.1%

4 photos range 9–9.9 %; shown is the average of the two that agree most closely.

LowSide photosource
Heel bevel height
AI estimated
16mm

4 photos range 15–16 mm; shown is the average of the two that agree most closely.

LowSide photosource
Midsole width (forefoot)
Externally measured
124.2mm
MediumLab testsource
Midsole width (heel)
Externally measured
93.4mm
MediumLab testsource
Toe box shape
AI estimated
70%

2 photos range 69–71 %; shown is the average of the two that agree most closely.

LowTop photosource
Interior forefoot width
Externally measured
97.8mm
MediumLab testsource
Toebox width
Externally measured
77.2mm
MediumLab testsource

Stiffness

Longitudinal stiffness
Derived
46/ 100

Lab reading: 16.7 N, force to bend the shoe 30° (lab bending test); the score is our 0–100 rescaling of it.

MediumLab flex testsource
Midsole firmness
Derived
42/ 100

Lab reading: 31.5 Asker C, midsole durometer reading (higher = firmer); the score is our 0–100 rescaling of it.

MediumLab durometersource

How it compares

Appears in:Carbon plateWide platformLonger toe rocker

Wrong value? Missing data? Tell me
Stored only to improve the site; see privacy.

Sources

  • Nike ACG Ultrafly Trail Trail Racing Shoes. Nike.commanufacturerNike.comaccessed 2026-10-04open ↗
  • Nike ACG Ultrafly Trail Unisex Shoes Crimson/Platinum/W | Running WarehouseretailerRunning Warehouseaccessed 2026-10-04open ↗
  • Nike ACG Ultrafly Trail Review – iRunFarreviewiRunFaraccessed 2026-10-04open ↗
  • nike-acg-ultrafly-trail medial product photoimageRunning Warehouseaccessed 2026-10-04open ↗
  • nike-acg-ultrafly-trail medial product photoimageRunning Warehouseaccessed 2026-10-04open ↗
  • nike-acg-ultrafly-trail lateral product photoimageRunning Warehouseaccessed 2026-10-04open ↗
  • nike-acg-ultrafly-trail lateral product photoimageRunning Warehouseaccessed 2026-10-04open ↗
  • Cut in half: Nike ACG Ultrafly Trail Review (2026) | RunRepeatlabRunRepeataccessed 2026-10-04open ↗
  • nike-acg-ultrafly-trail sole product photoimageRunning Warehouseaccessed 2026-10-04open ↗
  • nike-acg-ultrafly-trail top product photoimageRunning Warehouseaccessed 2026-10-04open ↗
Technical detail: every recorded value, method and version (34)

All approved observations

Every recorded value, including superseded ones. The displayed value per metric is chosen by precedence (measured › stated › derived › AI estimated), then confidence, then recency. 59 further observations awaiting review.

MetricValueClassConfidenceMethodSourceRecorded
Heel-to-toe drop8 mmStatedLowSpec listingNike.com2026-10-04
Heel-to-toe drop8.5 mmStatedHighSpec listingNike.com2026-10-04
Heel stack38 mmStatedMediumSpec listingRunning Warehouse2026-10-04
Forefoot stack28.5 mmStatedMediumSpec listingiRunFar2026-10-04
Forefoot stack29.5 mmStatedMediumSpec listingRunning Warehouse2026-10-04
Weight266 gStatedMediumSpec listingiRunFar2026-10-04
Weight267 gStatedMediumSpec listingiRunFar2026-10-04
Weight269 gStatedMediumSpec listingRunning Warehouse2026-10-04
Rocker apex63 %est.LowSide photoRunning Warehouse2026-10-04
Rocker apex62.9 %est.LowSide photoRunning Warehouse2026-10-04
Rocker radius56 %est.LowSide photoRunning Warehouse2026-10-04
Rocker radius57 %est.LowSide photoRunning Warehouse2026-10-04
Rocker rise angle26 degest.LowSide photoRunning Warehouse2026-10-04
Rocker rise angle25 degest.LowSide photoRunning Warehouse2026-10-04
Toe tip over ground34 mmest.LowSide photoRunning Warehouse2026-10-04
Toe tip over ground34 mmest.LowSide photoRunning Warehouse2026-10-04
Rocker angle at toe58 degest.LowSide photoRunning Warehouse2026-10-04
Rocker angle at toe58 degest.LowSide photoRunning Warehouse2026-10-04
Visible rocker lift onset77.4 %est.LowSide photoRunning Warehouse2026-10-04
Visible rocker lift onset77.2 %est.LowSide photoRunning Warehouse2026-10-04
Toe spring (relative)16.4 %est.LowSide photoRunning Warehouse2026-10-04
Toe spring (relative)16.4 %est.LowSide photoRunning Warehouse2026-10-04
Heel bevel length9 %est.LowSide photoRunning Warehouse2026-10-04
Heel bevel length9.2 %est.LowSide photoRunning Warehouse2026-10-04
Heel bevel height16 mmest.LowSide photoRunning Warehouse2026-10-04
Heel bevel height16 mmest.LowSide photoRunning Warehouse2026-10-04
Midsole width (forefoot)124.2 mmMeasuredMediumLab testRunRepeat2026-10-04
Midsole width (heel)93.4 mmMeasuredMediumLab testRunRepeat2026-10-04
Toe box shape71 %est.LowTop photoRunning Warehouse2026-10-04
Toe box shape69 %est.LowTop photoRunning Warehouse2026-10-04
Interior forefoot width97.8 mmMeasuredMediumLab testRunRepeat2026-10-04
Toebox width77.2 mmMeasuredMediumLab testRunRepeat2026-10-04
Longitudinal stiffness46 DerivedMediumLab flex testRunRepeat2026-10-04
Midsole firmness42 DerivedMediumLab durometerRunRepeat2026-10-04

Classes: Manufacturer stated · Externally measured · AI estimated · Derived · User reported. Hover a method for its identifier and algorithm version.

Source notes

  • Running Warehouse: sha256=1944e22b6a341890c70fa617169096b100bffd6d173fb8c50ed32c2840aef5af; 0.3
  • Running Warehouse: sha256=a354ce3b3faf018bbe5c2ba141a3ef9d67fd0d8a36eabe6806cec498b6c64da3; 0.3
  • Running Warehouse: sha256=64addc3c83392bf2e7a63b84d8cc1be71b1f29bedd0b502460d6ce5a63f73879; 0.3
  • Running Warehouse: sha256=c083bc603f882c8f78a68b673dab0cda56b577eff92909957ed68108d70739d0; 0.3
  • Running Warehouse: sha256=a0338b249496c6f44d5c2500cc7560e355c276b5780397747d87a55a21f1bcd4; 0.1
  • Running Warehouse: sha256=09f0ed51dcab7d72cf5fa64a2678d662c8cc7a47cc1a03d1ff825d05076a7208; 0.1

Shoes with similar geometry

Compare these →

Closest current models from other lines by stack, drop, rocker, toe height, stiffness, firmness, weight and width, whichever both shoes have.

Side profile illustration of the Scott Kinabalu Trail
Scott
Kinabalu Trail
Trail · No plate
Drop
8 mm
Heel
37 mm
Toe rocker
—

Very close on every shared measure

Side profile illustration of the Scott Kinabalu Ultra
Scott
Kinabalu Ultra
Trail · Rock plate
Drop
7 mm
Heel
40 mm
Toe rocker
34%

Very close on every shared measure

Side profile illustration of the New Balance FuelCell SuperComp Trail v2
New Balance
FuelCell SuperComp Trail v2
Trail · Carbon plate
Drop
8 mm
Heel
39 mm
Toe rocker
38%

Very close on every shared measure

Side profile illustration of the VJ Flow
VJ
Flow
Road/trail hybrid · No plate
Drop
10 mm
Heel
35 mm
Toe rocker
—

vs this shoe: 3 mm lower heel