ShoeGeometry

Altra Timp 6 vs Icebug Järv RB9X

Two shoes compared on measured geometry. Each cell carries a provenance badge; open a shoe for sources.

heel boneAltra Timp 6: heel 30 mm, forefoot 30 mm (drop 0 mm); toe rocker 31 % of length, radius 44 % of length; heel bevel 9 % of length, 11 mm high at the back, ending behind the heel bone (only the back edge is rounded).Altra Timp 6: toe rocker 31 % of lengthIcebug Järv RB9X: heel 29 mm, forefoot 25 mm (drop 4 mm); toe rocker not measured, typical shape drawn.
  • Altra Timp 630/30 mm · toe rocker 31 % · heel bevel 9 %
  • Icebug Järv RB9X29/25 mm · toe rocker not measured
Illustrative profiles, not photographs: drawn from published stack heights and photo estimates of the unloaded shoes on a common length (300 mm), heels aligned, toe to the left; dots mark where each toe rocker starts; the dotted vertical line is under the heel bone (12 % of length), so a heel curve reaching past it is a bevel in front of the heel bone. Dotted lines use typical values where a shoe has no measurement. Exact values are in the table below.

Which suits you

If you wantPickBecause
More cushioning under the heelAbout the same30 vs 29 mm heel stack
More under the forefootAltra Timp 630 vs 25 mm forefoot stack
A lower dropAltra Timp 60 vs 4 mm drop
A stiffer, snappier forefootIcebug Järv RB9X26 vs 62 /100 stiffness
A wider base under the forefootAbout the same113.9 vs 116 mm forefoot base

From the values below, with differences inside measurement noise shown as about the same. This describes the shoes, not what is right for your feet; comfort in the first few runs decides.

MetricAltra Timp 6
Trail · Trail
Icebug Järv RB9X
Trail · Trail
Heel-to-toe drop0 mmDerived4 mmDerived
Heel stack30 mmStated29 mmStated
Forefoot stack30 mmStated25 mmStated
Weight324 gStated340 gStated
Toe rocker31 %est.—
Rocker radius44 %est.—
Rocker rise angle29 degest.—
Rocker angle at toe66 degest.—
Toe tip over ground34 mmest.—
Visible rocker lift onset77.7 %est.—
Toe spring (relative)17.4 %est.—
Heel bevel length8.6 %est.—
Heel bevel height11 mmest.—
Midsole width (forefoot)113.9 mmMeasured116 mmMeasured
Midsole width (heel)84.4 mmMeasured93.9 mmMeasured
Toe box shape82 %est.—
Interior forefoot width99.2 mmMeasured93.3 mmMeasured
Toebox width81.9 mmMeasured74.2 mmMeasured
Longitudinal stiffness26Derived62Derived
Midsole firmness63Derived—
PlateNo plateNo plate
Primary foamAltra EGO MAXeTPU (66% Susterra bio-based)
List price$165$179

Key differences

  • Altra Timp 6's heel-to-toe drop is 0 mm, 4 mm lower than Icebug Järv RB9X's 4 mm.
  • Altra Timp 6's heel stack is 30 mm, 1 mm thicker than Icebug Järv RB9X's 29 mm.
  • Altra Timp 6's forefoot stack is 30 mm, 5 mm thicker than Icebug Järv RB9X's 25 mm.
  • Altra Timp 6's weight is 324 g, 16 g lighter than Icebug Järv RB9X's 340 g.

Read more about both shoes

We measure the shape. For how they feel over many miles, and for lab tests of cushioning, grip and fit:

Altra Timp 6

Icebug Järv RB9X

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Altra Timp 6 details · Icebug Järv RB9X details · Add more shoes