How to Detect Cracks or Delamination in Carbon Wheels

Carbon wheels offer incredible performance, lightweight design, and aerodynamic benefits, but they require careful inspection and maintenance. One of the most serious concerns for carbon wheel owners is cracks or delamination, which can compromise both safety and performance.

If left undetected, these issues may lead to sudden failure.
This guide will help you understand how to spot damage early and what to do if you find it.

Why Carbon Wheels Require Regular Inspection

Carbon fiber is extremely strong, but it behaves differently from metal. While alloy rims can often bend or deform visibly before failure, carbon rims are more likely to crack or delaminate without warning.

Key risks include:

Impact damage (potholes, curbs, crashes)

Heat buildup (from prolonged braking, especially with rim brakes)

Manufacturing defects (rare but possible)

Common Signs of Carbon Wheel Damage

Here’s what you should regularly check on your carbon wheels:

1. Visible Cracks on the Rim Surface

Look for small hairline cracks, especially:

Around spoke holes

Near the tire bed

On the brake track (for rim brake wheels)

Along the sidewalls

Cracks may appear as straight lines, spider-web patterns, or small chips.

2. Bulging, Soft Spots, or Uneven Rim Surfaces

Run your fingers along the rim surface. Bulges or soft areas may indicate internal delamination (layers separating within the carbon structure).

3. Unusual Noises While Riding

Clicking, creaking, or cracking sounds that repeat with each wheel revolution can signal internal damage.

Persistent noises after spoke or hub adjustments may point to rim issues.

4. Unexplained Loss of Trueness

If your wheel frequently goes out of true, even after multiple spoke adjustments, it may indicate a compromised carbon structure.

5. Discoloration or Surface Deformation

Burn marks, blistering, or deformed areas on the brake track may suggest heat damage (especially from excessive rim braking on descents).

How to Perform a Detailed Home Inspection

Step 1: Visual Check

Clean your wheels thoroughly.

Use bright light and inspect all areas carefully.

Pay special attention to high-stress zones: spoke holes, valve holes, tire bed, brake track.

Step 2: Sound Test

Lightly tap the rim with your fingernail or a coin.

Listen for consistent, sharp sounds.

Dull or hollow sounds may indicate delamination.

Step 3: Pressure Test

Gently press with your thumb along the sidewalls and rim bed.

The rim should feel solid throughout—any soft spots suggest internal damage.

Step 4: Ride Feel

If you suddenly feel flex, vibrations, or excessive brake rubbing, stop and inspect your wheels immediately.

Key Safety Tip:

If you suspect damage, stop using the wheel immediately. Riding on a cracked or delaminated carbon wheel is extremely dangerous.

What to Do If You Find Damage

Minor Surface Chips: Often cosmetic. If in doubt, consult your wheel manufacturer.

Cracks, Bulges, or Delamination:
Stop riding and contact the manufacturer or a certified carbon repair specialist.

Warranty Check: Some brands (including Superteam) offer crash replacement or inspection services—review your warranty coverage.

Can Carbon Wheels Be Repaired?

Small cosmetic chips: Usually fine to ride after inspection.
Structural cracks: Sometimes repairable by professional carbon repair shops, but not always cost-effective.
Major delamination: Often unsafe to repair—replacement is recommended.

Final Thoughts

Regular inspection is essential for carbon wheel safety.
While carbon wheels are durable and race-proven, they must be treated with more care than alloy wheels.

At Superteam, we recommend:

Frequent visual inspections (especially after impacts or hard braking descents)

Listening to your bike for unusual sounds

Your safety always comes first.
When in doubt, get it checked by a professional.