ShoeGeometry

Icebug Järv RB9X

TrailTrailNo plate2025Men'sCurrent

At a glance

Heel-to-toe drop
4 mmDerived
Stack, heel / forefoot
29 / 25 mmStated
Weight
340 gStatedUS M9
Plate
No plate
Toe rocker
not measured yet
Heel bevel
not measured yet
Stiffness / firmness
62 / — of 100Derived
Primary foam
eTPU (66% Susterra bio-based)

How it compares

  • Icebug Järv RB9X's heel-to-toe drop is 4 mm, lower than the catalogue median of 6 mm (5% of the 179 other current shoes are lower).
  • Icebug Järv RB9X's heel stack is 29 mm, thinner than the catalogue median of 38 mm (6% of the 176 other current shoes are thinner).
  • Icebug Järv RB9X's forefoot stack is 25 mm, thinner than the catalogue median of 31.5 mm (8% of the 171 other current shoes are thinner).
  • Icebug Järv RB9X's weight is 340 g, heavier than the catalogue median of 269 g (99% 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
Derived
4mm
MediumCalculated
Heel stack
Manufacturer stated
29mm
LowSpec listingbrand figure, reported by Believe in the Runsource
Forefoot stack
Manufacturer stated
25mm
LowSpec listingbrand figure, reported by Believe in the Runsource
Weight
Manufacturer stated
340g
MediumSpec listingbrand figure, reported by Believe in the RunUS M9source
Plate
No plate
Primary foam
eTPU (66% Susterra bio-based)
List price
$179

Geometry

Catalogue average: heel 38 mm, forefoot 32 mm, toe rocker 34 %Icebug Järv RB9X: heel 29 mm, forefoot 25 mm (drop 4 mm); toe rocker not measured, typical shape drawn.29 mm25 mmtoeheel
Front: toe rocker shorter longerRear: heel stack lower higher not measured
Dashed: average of the catalogue
  • Toe rocker not measured: typical curve drawn
  • Heel bevel not measured: generic rounding drawn
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. Icebug Järv RB9X: heel 29 mm, forefoot 25 mm (drop 4 mm); toe rocker not measured, typical shape drawn. Dashed midsole: typical values stand in for what this shoe has no measurement of.

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.

Midsole width (forefoot)
Externally measured
116mm
MediumLab testsource
Midsole width (heel)
Externally measured
93.9mm
MediumLab testsource
Interior forefoot width
Externally measured
93.3mm
MediumLab testsource
Toebox width
Externally measured
74.2mm
MediumLab testsource

Stiffness

Longitudinal stiffness
Derived
62/ 100

Lab reading: 19.8 N, force to bend the shoe 30° (lab bending test); the score is our 0–100 rescaling of it.

MediumLab flex testsource

How it compares

Appears in:Low drop

Compare:Icebug Järv RB9X vs Altra Lone Peak 9Icebug Järv RB9X vs Altra Superior 7

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Sources

  • Icebug Järv RB9X Review: Ready for the Spring Thaw | Believe in the RunreviewBelieve in the Runaccessed 2026-10-04open ↗
  • Cut in half: Icebug Järv RB9X Review (2025) | RunRepeatlabRunRepeataccessed 2026-10-04open ↗
Technical detail: every recorded value, method and version (9)

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. 18 further observations awaiting review.

MetricValueClassConfidenceMethodSourceRecorded
Heel-to-toe drop4 mmDerivedMediumCalculated—2026-10-04
Heel stack29 mmStatedLowSpec listingBelieve in the Run2026-10-04
Forefoot stack25 mmStatedLowSpec listingBelieve in the Run2026-10-04
Weight340 g (US M9)StatedMediumSpec listingBelieve in the Run2026-10-04
Midsole width (forefoot)116 mmMeasuredMediumLab testRunRepeat2026-10-04
Midsole width (heel)93.9 mmMeasuredMediumLab testRunRepeat2026-10-04
Interior forefoot width93.3 mmMeasuredMediumLab testRunRepeat2026-10-04
Toebox width74.2 mmMeasuredMediumLab testRunRepeat2026-10-04
Longitudinal stiffness62 DerivedMediumLab flex testRunRepeat2026-10-04

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

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 Saucony Peregrine 16
Saucony
Peregrine 16
Trail · Rock plate
Drop
4 mm
Heel
32 mm
Toe rocker
37%

vs this shoe: stiffer · 3 mm higher heel

Side profile illustration of the Nike ACG Pegasus Trail
Nike
ACG Pegasus Trail
Road/trail hybrid · No plate
Drop
4 mm
Heel
35 mm
Toe rocker
35%

vs this shoe: 6 mm higher heel · more flexible

Side profile illustration of the La Sportiva Prodigio Max
La Sportiva
Prodigio Max
Trail · No plate
Drop
6 mm
Heel
36 mm
Toe rocker
—

vs this shoe: 7 mm higher heel · 34 g lighter · 2 mm more drop

Side profile illustration of the Altra Timp 6
Altra
Timp 6
Trail · No plate
Drop
0 mm
Heel
30 mm
Toe rocker
31%

vs this shoe: more flexible · 4 mm less drop