How to Detect Cracks or Delamination in Carbon Wheels: A Complete Ride

Carbon wheels offer exceptional performance, but they also require careful inspection and maintenance. One of the most serious risks with carbon wheels is cracks or delamination—hidden damage that can lead to catastrophic failure if ignored.

In this guide, you’ll learn:

What cracks and delamination look like

How to safely inspect your carbon wheels

When to repair, replace, or consult a professional

What Are Cracks and Delamination in Carbon Wheels?

Cracks are visible fractures on the surface or structure of the carbon rim.
Delamination occurs when the bonded layers of carbon fiber start to separate internally.

Both issues can be caused by:

Hard impacts (potholes, crashes, curbs)

Heat buildup (especially on rim brake wheels)

Long-term fatigue

Manufacturing defects (rare, but possible)

If left unchecked, these problems can severely weaken your wheelset.

Common Signs of Carbon Wheel Damage

1. Visible Cracks on the Rim

Around spoke holes

Near the tire bed

Along the brake track (rim brake wheels)

On the rim sidewalls

Look for straight lines, spider-web cracks, chips, or separation at joints.

2. Bulges or Soft Spots

Run your hands along the rim.

A bulge, dent, or soft area may indicate internal delamination.

Even small deformations can compromise wheel safety.

3. Unusual Noises While Riding

Repeated clicking, creaking, or popping sounds may signal carbon fiber separation.

If the noise persists after hub and spoke adjustments, the rim may be the issue.

4. Frequent Loss of True

If your carbon wheel repeatedly goes out of true, it may indicate a weakened structure that can no longer hold proper tension.

5. Discoloration or Heat Damage

On rim brake wheels, dark burn marks or blistering along the brake track suggest overheating and possible delamination.

Step-by-Step: How to Inspect Your Carbon Wheels at Home

Step 1: Clean Your Wheel

Use a soft cloth and inspect under a bright light.

Remove any dirt that could hide cracks.

Step 2: Visual Check

Carefully inspect spoke holes, valve holes, sidewalls, tire bed, and braking surface.

Use a magnifying glass if necessary.

Step 3: Sound Test

Lightly tap the rim with a coin or fingernail.

Consistent, sharp sound = good.

Dull, hollow, or muted sound = possible delamination.

Step 4: Pressure Test

Gently press the rim walls with your thumbs.

Feel for softness, flexing, or bulging.

The rim should feel solid all the way around.

What to Do If You Find Potential Damage

Cosmetic Scratches/Chips: Usually safe, but monitor regularly.

Visible Cracks/Bulges: Stop riding immediately.

Delamination Signs: Stop using the wheel and consult the manufacturer or a carbon repair specialist.

Some manufacturers (like Superteam) offer crash replacement programs or free inspections.

Can Carbon Wheels Be Repaired?

Damage Type	Recommended Action
Cosmetic Surface Chips	Continue riding, monitor regularly
Small Localized Cracks	Professional repair may be possible
Major Cracks/Delamination	Replacement recommended
Heat Damage (Rim Brake Wheels)	Replacement recommended

Important: Never attempt structural carbon repairs yourself.