The Kevlar Debate For Brake Lines

Many of our customers ask us why we will not sell Kevlar® reinforced brake lines for the motorcycle marketplace and the answer is simple. 

Kevlar® is an Aramid fiber introduced by DuPont® in 1971. Kevlar has become a predominant fiber in the high performance racing sector for many parts such as body armor and fairings.  It is stronger than steel for its weight and has a modulus that is five times greater than polyester.  When Kevlar® was first introduced there were two types: Type 29 and Type 49 (High Modulus).  Type 49 has a 50% higher initial modulus than Type 29 and lower flex strength.  Other Kevlar® styles (Types 129, 149 and 159) have also been developed but are less used since the higher strength goes hand in hand with lower flex strength.  

But....

Additional drawbacks of Kevlar® include poor UV resistance (Kevlar® loses strength roughly twice as quickly in sunlight as polyester and, when affected, the gold Kevlar® fibers turn brown) and rapid loss of strength with flexing, folding and flogging. 

As you can see this product needs to be covered so that UV sunlight does not effect it's strength and reliability. Therefore all brake lines which are sold as a Kevlar® (or Aramid if the company does not use the original DuPont® designed Kevlar® and only a copy) must have a pvc cover on the outside to protect the Kevlar® from UV rays.

This also means that if a stone flicks up, which when riding a bike is quite likely, and cuts or removes some of the outer protective cover the Kevlar® braid will be exposed to UV and lose strength. This fact coupled with the fact that Kevlar® has rapid loss of strength with flexing (and how many times will your brake lines flex with the movement of suspension) make this, in our opinion, an inferior and dangerous choice when considering the best materials for use in brake lines - After all this is what makes your motorcycle stop...

You have been warned and the choice is yours but we will NOT sell Kevlar® or the unbranded 'Aramid' hoses for your motorcycles brake lines. We repeat the following statement again :

'Additional drawbacks of Kevlar® include poor UV resistance (Kevlar® loses strength roughly twice as quickly in sunlight as polyester and, when affected, the gold Kevlar® fibers turn brown) and rapid loss of strength with flexing'.

Kevlar® is great in the correct environment but not as a cover for motorcycle brake lines - You have been warned. They may offer you a few grams of weight saving but is it really worth it ? The few race teams who use Kevlar replace every line after each event so the flexing / UV issues are not valid but do you want to replace your lines every month ?

HEL Performance only ever use stainless steel or Titanium fittings on stainless steel hose with stainless steel or Titanium bolts offering no loss of strength when subjected to UV. So Ride the best you can - Fit HEL Performance Brake Lines.

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Kevlar® is a registered trademark of DuPont®