Heat-molding, made simple

Intro
Custom fit beats stock fit. This guide shows how to heat-mold your CarbonShell™ cycling shoes at home—either with a fan-assisted oven for global shaping or a heat gun for precise tweaks. The method comes straight from speedskating’s 30+ years of practice: gentle heat, small adjustments, and inside-out pressure. In speed skating, they often use a vacuum pump to create outside pressure; we advise doing the opposite for cycling shoes. You’ll use temporary “bumps” (5–10 layers of sports tape or a thin foam pad) to cue the warm carbon where to give, then load the forefoot so the shell adapts to your foot anatomy.

Work one shoe at a time, think millimetres not centimetres, keep heat moving, and avoid hardware.

Table of contents

We recommend you also check this video with molding tips and tricks for our cycling shoes.

What tools can I use for heat-molding (CarbonShell™)?

You don’t need a workshop—smart household items work great. After gently heating the target area, use smooth, rounded tools from the inside to nudge the shape.

Heat source

Heat gun (low–medium): keep ~30 cm distance, always moving.

Heat gun boot boot molding

Fan-assisted electric oven: ~80 °C / 180 °F for 12–15 min (remove insoles).

Oven for heat molding
(Hair dryers are usually too weak.)

For pinpoint bumps / small domes
Deodorant stick (rounded end) • Small wrapped socket (10–13 mm) • Pestle • Golf/squash ball

For longer ridges (arch/carbon lip)
Wooden spoon or ladle • Rounded end of a mini bike pump (wrapped) • Adjustable shoe tree (bonus: bunion plugs)

To hold shape while cooling (no plastics)
Tightly rolled microfiber cloth/small towel • Cotton sock filled with dry rice/beans • Leather belt roll • Cork block/ball • Silicone oven mitt/pad

Protection & safety
Wrap hard/metal tools in a thin cloth; use a folded towel outside as counter-pressure. Target 70–80 °C / 160–180 °F locally; stay below ~80 °C / 180 °F. Avoid BOA dials, seams, decals. Think millimetres, not centimetres.

How to relieve arch pressure for flat feet (CarbonShell™)

What you’ll need: heat gun (low–medium), thin glove, rounded former (thumbs, wooden spoon handle, smooth dowel).
Before you start: remove the insole and fully loosen closures. Keep the heat gun ~30 cm away and moving.

Step-by-step

  1. Mark the hotspot – Place a fingertip inside the shoe on the exact pressure point.
  2. Warm just the arch area – Sweep the heat gun from ~30 cm until the liner feels clearly warm (~70–80 °C / 160–180 °F).
  3. Keep heating until you can clearly feel warmth at your fingertips inside the shoe—this tells you the material is warm all the way through. This usually takes about 5 minutes (up to ~10, depending on the tool).
  4. Push the lip out – While warm, press from the inside to move the carbon edge 1–2 mm along 5–7 cm, aiming for a smooth curve.
  5. Hold while it sets – Maintain steady pressure until fully cool, about 4-5 minutes.
  6. Reassemble & test – Reinsert insole, check fit, repeat in small steps if needed.

Tips & cautions
Keep heat moving; avoid hardware. Stay below ~80 °C / 180 °F. This does reshape the carbon shell—small, repeatable changes win. Prefer targeted heat-gun work once global fit is set.

How to gently widen the toe area (CarbonShell™)

What you’ll need: heat gun (preferred), thin work glove, rounded object slightly larger than the spot to widen.
Before you start: remove the insole and fully loosen closures; set heat gun to low–medium.

Step-by-step

  1. Identify the spot – Fingers inside the toe box at the area needing space.
  2. Warm the area – Heat from ~30 cm, always moving, until you feel warmth at your fingertips.
  3. Mould the shape – Press the rounded object from the inside to create a smooth, gentle bulge.
  4. Hold while it sets – Maintain pressure until fully cool.
  5. Reassemble & test – Try the fit; repeat in millimetre steps if needed.

Tips & cautions
Yes, you’re reshaping the carbon shell—within limits. Avoid heating dials/seams directly.

How to tighten the heel cup (CarbonShell™)

What you’ll need: fan-assisted oven (preferred) or heat gun (low–medium), thin gloves, folded towel/mouse pad, and a helper.
Before you start: remove the insole, fully loosen closures.

Step-by-step

  1. Pre-heat the heel zone – Oven: ~80 °C / 180 °F for 8–12 min (even, global soften). Heat gun: sweep medial/lateral sides of the heel counter until evenly warm (~70–80 °C / 160–180 °F).
  2. Sit down – Keep one leg straight, toes up. Reinsert the insole; heel fully back in the pocket
  3. Squeeze technique (helper) – Sit facing the athlete. Interlace your fingers to support the heel, then press your palms together to squeeze the heel cup inward—just above the heel bone and below the ankle joint.. Hold 3–4 min as it cools.
  4. Cool & test – Let cool fully; retest. Repeat in small increments if needed.

Tips & cautions
Small, repeatable changes. Stay below ~80 °C / 180 °F. If you’re also doing other areas, oven first; then local tweaks.

Key idea: apply inside-out pressure with the shell warm. The foot (26 bones, 30+ joints) deforms under load—subtalar pronation and midfoot unlocking lower the arch, while the forefoot splays and the foot lengthens by a few millimetres. Harness that deformation to persuade the carbon where to yield.

What you’ll need: heat gun (low–medium), sports tape, thin glove, folded towel/mouse pad.

Step-by-step

1) Tape the hotspot on your foot – Layer 5–10 strips of sports tape over the navicular (inside ankle) or base of the 5th met (outside).
2) Warm the shoe locally – Heat the matching area from ~30 cm to ~70–80 °C / 160–180 °F.
3) Reinsert insole, step in, and load it – Stand on one leg and shift weight to the ball of the foot (pedal-axle line).
4) Hold while it sets – Stay loaded 3–4 min until firm.
5) Remove tape & test – Retest; repeat with more/less tape if needed.

Tips & cautions
Think millimetres. For global changes (e.g., heel cup), oven first, then local heat-gun.

What’s the correct order: oven vs heat gun? (CarbonShell™)

Short answer: oven first, then heat gun.
A full oven warm-up returns the shoe close to neutral/factory shape, relaxing earlier local tweaks. Do the global fit in the oven, then fine-tune with a heat gun.

Step-by-step

1) Prepare – Remove insoles, loosen closures. Oven ~80 °C / 180 °F, 12–15 min.
2) Set the global fit – Step in, center weight over the forefoot; tighten/taper heel cup; cool to firm.
3) Targeted adjustments – After cooling, heat specific spots (~70–80 °C / 160–180 °F) and shift the carbon 1–2 mm from the inside; hold until cool.

Tips & cautions
Avoid global re-heating after local tweaks (it will make them disappear). Keep heat off dials/seams; re-check cleat bolts after heat work.

How to add more “inside-out” pressure when molding (CarbonShell™)

Short answer: add a temporary pad on the foot or over the carbon edge to amplify pressure—then heat, load, cool, remove.

Option A — Pad on the foot (bony hotspots)
Cut a 3–6 mm foam oval/teardrop (mouse-pad/EVA/neoprene) with rounded edges. Tape it to your skin over the hotspot (navicular or base of 5th met). Warm locally, stand on one leg, load the forefoot, hold 3–4 min, remove pad, test.

Option B — Pad on the carbon edge (low arches / sharp arch lip)
Cut a 20–25 mm × 50–70 mm strip; tape it over the inner arch. Warm, step in, load, hold, remove.

Extra leverage (optional)
While the shoe is warm, use a rounded tool inside (e.g., wooden spoon handle, wrapped) to create extra pressure to smooth the curve.

Safety & notes
Pads are temporary—don’t ride with them. Keep changes small; prefer cotton/fabric-faced foam; avoid hard plastics. Oven first for global shaping, then local tweaks.