Carbon Fiber vs. Fiberglass

What’s the difference between carbon fiber and fiberglass running blades? And which is best for you?

We’ll help you get a better understanding of both materials and which scenarios are better for each so you can make an informed choice before getting your next running blade.

What exactly are carbon fiber and fiberglass?

What we call carbon fiber and fiberglass are actually fiber-reinforced polymers. In other words, they’re a sort of reinforced plastic.

These composite materials are made of extremely fine fibers that get layered together like textiles and permeated with plastic resin that after drying, forms a sheet with great strength-to-weight ratios.

Why combine two different materials? When combined, the materials act together, each overcoming the deficits of the other. Whereas plastic resins are strong in compressive loading and relatively weak in tensile strength, fibers are very strong in tension but tend not to resist compression. By combining the two materials, fiber-reinforced polymers become a material that resists both compressive and tensile forces well.

Carbon fiber is a tiny (5 to 10 micrometers in diameter) strand of carbon atoms bonded linearly, making it amazingly strong. Fiberglass is similar to carbon fiber, but the thin glass filaments are larger than carbon and not quite as strong. However, the increased strength and rigidity of carbon fiber do not necessarily make it a better choice for all applications. Fiberglass is a far better choice for applications that entail high flex patterns. Due to this reason, fiberglass is generally considered tougher than carbon fiber since its more flexible nature enables it to withstand stress and physical abuse more easily.

 

So which is best for you?

Carbon fiber is lighter and stiffer, so if you’re a serious competitor who’s measuring performance in hundredths of a second, then that can make a difference. But if you just want to enjoy yourself, those fractional performance intervals are meaningless.

Fiberglass is more flexible, durable, and cheaper. The greater flexibility will make the running blade feel softer and more comfortable on your leg. This will be preferable if you’re just looking to start running, exercising, or playing sports for the fun of it. That’s why we made the Levitate blade kit out of primarily unidirectional fiberglass.