Three-Point Seatbelts: Also called a combination belt, these have a lap and a shoulder strap with three attachment points. As well as keeping the passenger in the vehicle in the event of an accident, the shoulder strap helps prevent passengers from impacting surfaces inside the car.
Five-Point Harnesses: Most often found on child safety seats and race cars, the lap strap is connected to another between the legs and there are two shoulder belts, making a total of five points of attachment to the car. While safer than two- and three-point belts, they are very restrictive and can make operating a vehicle difficult in normal circumstances.
Six-Point Harnesses: Found in many race cars, including NASCAR, these are similar to a five-point harness but include an extra belt between the legs.
Inertia Reels: Found in virtually every contemporary vehicle, inertia reels allow the belts to be self-adjusting. When pulled out slowly, the belts can be secured; but a centrifugal clutch engages when the reel spins quickly, or a weighted pendulum that locks on sudden deceleration keeps the belts tight when necessary. Inertia reels also retract the belts when not in use.
How many points are enough?While seatbelts are certainly a worthwhile addition to any car, street rods included, there are a variety of things to consider when choosing the type to install.
Although being strapped into a race car with a five- or six-point harness provides a real sense of security for a driver, they are not very practical for street use. And while lap belts allow the most freedom of movement and are certainly the easiest to install, we wanted something more. In our case, the vehicle in question is a Model A pickup. Because of the close confines of the closed cab, we felt lap belts wouldn't keep the occupants' heads from smacking something unforgiving in the event of an accident. For that reason, we chose retractable three-point shoulder harnesses from Juliano's Hot Rod Parts & Interior Products.
We've used several versions of Juliano's lap and three-point belts in other street rods and found them to be quality products that were easy to install. But, in the case of our Model A, we were faced with two unique challenges. The first was limited space for the seatbelt reels and the second was the lack of secure anchor points for the shoulder straps.
To make room for the retractor assemblies, we simply reversed their normal mounting orientation so the belts fed off the reel toward the outside of the cab (refer to photos) and notched the corners of the seat riser. Adding mounting points for the shoulder straps was a bit more complicated. In many early cars, our Model A included, wood was used for the internal structure. It should go without saying that anchoring the shoulder straps to wood isn't a good idea. So, we fashioned a pair of steel reinforcements that were welded and bolted in place on both sides of the body to provide the mounts with the necessary strength.
Juliano's seatbelts and shoulder harnesses are available in a variety of colors and feature OEM styling and quality. But, while being unobtrusive and convenient to use are real advantages, the most important thing about them is the safety they provide. Hopefully that's something none of us will have to find out firsthand.