For those familar with CMC structure... The mounting thread, for the soft top, encased in the fiberglass wall, located about shoulder high, behind each seat, How secure is this ? I can not find a way to view it. I was wondering if it could be used to mount the pivot/turn for a retractable three point seatbelt?
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Forget the 3 pt. To work effectively they need to mount above your shoulder (or you'll crush your collar bone). This can only be achieved with a D-ring stand. Racing lap belts, like Simpsons work better and are more comfortable.
You can view it if you look up from the wheel well. It is not secure at all for a seat belt mount. I easily loosened it to change the angle.
Forget the 3 pt. To work effectively they need to mount above your shoulder (or you'll crush your collar bone). This can only be achieved with a D-ring stand. Racing lap belts, like Simpsons work better and are more comfortable.
And unless you have a structural roll-bar, I'd stick with lap belts only. I have four-point belts in my Spyder, but only use the shoulder belts when the STRUCTURAL roll bar is installed. No sense in turning your head into an eraser on rollover....
Crow and Diest make good vintage looking latch-type belts too
The serious danger of improperly mounted seat/shoulder belts is that if the belt material is attached too low going to the rear, you are almost guaranteed a spinal compression injury in the result of an accident, because your body is forced downward by the belt angle. A broken collarbone is minor, while a spinal injury stays forever. If you want more info, just Google "seat belt installation". Many of the popular brands have instructions on their websites. Properly installed lap belts are much safer than improperly installed shoulder belts. Coupe and 911 owners can buy a harness bar that spans the width of the car at roofline, attaching to the b posts, giving an upward angle for rear attachment points. Roll cages offer the same attachment points.
Forget the 3 pt. To work effectively they need to mount above your shoulder (or you'll crush your collar bone). This can only be achieved with a D-ring stand. Racing lap belts, like Simpsons work better and are more comfortable.
I would argue that having the steering column punch through your sternum is probably more likely to be fatal than the spinal compression damage from having the shoulder belt too low. But spinal injury is more likely at lower collision speeds than fatal chest injury.
Regardless, the existing top bow mount is not strong enough for a seatbelt mount.
One of the reasons I had a rollbar installed in my IM during its restoration was so I could mount four point seat belts.
