R-4 Woven Kevlar
Porterfields Woven Kevlar is high friction woven
composite material designed for use in mechanically
actuated drum brake systems. It has
very high friction at ambient and low temperatures
for good initial bite and may be bonded
to aluminum or steel brake shoe cores. Trusted
by top car mechanics to stop the most valuable
of vintage vehicles safely, without any unnecessary
drum wear. This material is widely used
in vintage racing and vintage touring events on
vehicles with mechanical drum brakes.