Schroth Rallye 4 ASM Harness
The Schroth Rallye 4 is the de-facto standard for anyone looking for a simple, safe, DOT-approved 4 point harness. The technology built into this harness puts it in a category above belts made by other manufacturers. Schroth's years of testing and motorsport experience are brought to bear in making this 4-point harness as safe as it can be.
SCHROTH TECHNOLOGY STANDS ABOVE THE REST
There are two main reasons why the Schroth harnesses are the only safe 4-point harnesses: first, ASM technology; second, the ability to install the harness using stock mounting locations.
ASM stands for "Anti-Submarining". It's an extra flap of technical material sewn into the inboard shoulder belt that prevents you from sliding underneath the lap belt in a crash. In a typical 4-point harness, the two shoulder straps restrain your upper body equally, keeping your chest from moving forward but also pulling up on the lap belts. This allows your pelvis to slide under the lap belt, which can cause serious damage.
With ASM, the shoulder belts will elongate at different rates, allowing your torso to turn slightly which forces your pelvis down into the seat cushion. Upon rebound, you will be placed back in an upright position with the belt correctly placed over your body.
STOCK MOUNTING POINTS ARE THE STRONGEST
Being able to mount a Schroth Rallye 4 ASM harness to stock mounting locations means you're using the points engineered by the car maker to withstand extremely high forces for a specified length of time. That means the mounting bolts won't pull out of the sheet metal.
It also means (in the case of a Schroth harness) that you can retain the use of your stock 3-point harness, allowing you the use of the backseat of your car. If you have the need to transport passengers (or cargo) in your backseat, it is possible to disconnect the tailstrap (a feature only Schroth has) and use your normal 3 point belts.
See Schroth Harness Installation Checklist Here
