The Strap Drive System (Patent Pending) has been developed by AP Racing both for Road and Race applications. The standard fitment discs on many performance cars can suffer from brake vibrations caused by disc distortion. This generally occurs on fast road and track installations.
On many performance cars the typical standard disc will be a heavy duty ventilated single piece casting. Couple this type of rigid disc to a standard hub and wheel bearing and the result is any hub distortion / run out will transfer onto the disc brake faces. This eventually results in brake vibrations, usually picked up through the steering wheel.
The strap drive system offers a new take on the floating systems already in the market place. Strap drive uses a series of stainless steel straps to locate the disc to the mounting bell, producing a flexible coupling between the hub and the disc faces. This allows the disc to run true in the caliper under all conditions and also permits the disc to expand and contract without being restricted. Some current replacement discs in the market place have evolved from Motorsport applications, they typically use a drive bobbin to provide some disc float and were devised to reduce pad knock off on race cars. This system can work on a road application but there are some major drawbacks that the Strap Drive has overcome with its simplicity.
Bobbin float discs rely on a series of drive bobbins moving freely in drive slots. This movement can create wear during service and promote noise. The slots can fill up with road / brake debris causing them to seize. AP Racings strap couplings can't suffer from any of these drawbacks. Therefore Service life, brake noise and also brake pedal travel are all improved.
AP Racing has also introduced the strap drive system into a number of our current brake kit range.