All about carbon fiber motorcycle crash helmets

Carbon fiber is a composite material usually made up of a carbon fiber weaved fabric set in a resin – usually plastic.

The great thing about carbon fiber, as far as we’re concerned, is that it looks cool when you make a crash helmet out of it. Oh, and it’s very strong for its weight!

This last part is why helmet manufacturers have been keen to use carbon fiber in the construction of their top-end crash helmets for the last ten years of course. But it does have a downside.

Carbon fiber Bell Pro Star – Tracer design

That’s because crash helmet shells need to have a certain amount of flex in them to try and absorb energy and stop it passing through to the brain. And carbon fiber is very strong and stiff so very resistant to flexing.

Which can present a challenge to a helmet maker.

Having said that, they mostly seem to have overcome this problem because, as you can see from our comparison of helmet shell material versus SHARP helmet safety score in the table below, carbon fiber helmets overall perform superbly well. They seem to manage to be lighter, stronger and offer fantastic shock-absorption qualities all at the same time.

That’s probably because most helmets that use carbon fiber include it as part of a composite – often including layers of fiberglass, kevlar, plastic and other custom-designed materials working alongside carbon fiber. This allows helmet makers to tune the performance of the shell to give as close to the right set of characteristics they’re looking for. Even many ‘pure carbon’ helmets on sale today are actually composites. Which is no surprise really because carbon fiber itself is a composite material.

Helmet ShellAvg SHARP safety score (Max 5)Avg weight Lbs (Kg)
Carbon4.253.0 (1.36)
Composite3.763.2 (1.46)
Fiberglass3.63.3 (1.49)
Polycarb/thermoplastic3.33.46 (1.57)
Full Face3.63.24 (1.47)
Modular/flip3.353.75 (1.7)


Carbon fiber ‘Carbon Pure’ Nexx XR2 – one of the lightest helmets around at 1.27Kg

The way carbon fiber is made is by creating a carbon thread then weaving it into a material. Doing this gives it strength in two planes. This is then set into a binder – usually a thermoplastic resin (the stuff that thermoplastic helmets are made out of) which gives it three dimensional strength. Using multiple layers together multiplies that strength further.

It’s not quite so straightforward though because there are lots of different grades of thread quality, weaves and binders, all offering a multitude of material characteristics and available at exotic and startling price points!

For example, the Bell Pro Star race helmet, uses a special flatter, stronger carbon fiber called TeXtreme which partly accounts for it’s higher price. Its sister helmet, the slightly cheaper Bell Race Star uses a 3K carbon fiber weave which is slightly bulkier and has a different finish.

You’ll often hear terms like 3K and 6K carbon fiber. This refers to the number of carbon fiber filaments in each carbon thread. So 3K carbon fiber has 3000 filaments and is the ‘workhorse’ good all rounder type of carbon fiber, whereas the 6000 filament 6K carbon fiber is slightly cheaper and with a thicker weave.

Of course, because carbon fiber is expensive to buy and use, helmet makers tend to use it mostly in their top of the range helmets. And those helmets tend to have more care and attention and better quality materials lavished on them anyway – hence their better overall performance.

However, the fact of the matter is that if you were wanting to buy a safe crash helmet and are going to base your buying decision on helmet shell material alone, then you’re probably best going for a carbon fiber helmet.

So there you go. Carbon fiber isn’t just pretty, it’s strong (and pricey) too. And it allows helmet manufacturers make some great looking, great performing and lightweight motorcycle helmets to keep our heads safely cossetted doing what we love most.

So if you’re in the market for a carbon fiber helmet, then visit our carbon fiber crash helmets page where you can read all our carbon fiber helmet reviews and previews.


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