Seat belt question

[FMO]

Is it possible to use the backseats , after Installing a roll bar?

regards
FMO

[Klayfish]

I'm by no means an accident reconstructionist, but I do have some experience in this subject. I work in the auto insurance claims business. I've been an appraiser (still have my license), adjuster, claims manager and am now a consultant. So I've seen literally tens of thousands of car/truck crashes and gone to many training classes/seminars.

I totally agree that a proper 3 point belt mounted high (or a 4/5 point harness secured to a roll bar) is ideal. No doubt. But in the absense of that, I'd say that a 3 point belt mounted securely to the floor is a much better option than a lap only belt. Keep in mind that in a crash, it's not the seatbelt retractors that generate the real g forces on you, it's the force of the impact. The belt is primarily designed to hold you in place. So if you mount the belt to the floor, yeah, it's going to put a little more pressure on your shoulder area in a crash, but I don't see it causing spinal fractures or shoulder fractures or anything like that. Sore trapezius muscles, maybe. In a frontal crash, your body wants to fly forward, so your chest will push up against the belt. Where it's mounted vertically will only make a small difference, IMHO. I think the bigger difference will come from where it's mounted laterally. You need to make sure it comes up across your left shoulder at a proper angle and across your chest, then buckle at the your right hip. If it's angled wrong, it could come across your neck, which would not be good.

Lap only belts are definitely not a good thing. As dhagood pointed out, it would be more than just a nose hitting the steering wheel. Your head smashs the steering wheel/dashboard area, with dire consequences. And if you're lucky enough not to hit the wheel (maybe you're riding as a passenger), the internal injuries the lap only belt will cause can range from quite painful to fatal.

[GTO]

My 73 spyder had the seat belt mounted on the floor behind the driver. In the UK this is a no no. When I restored the car I found it had belt mounting points on the inner rear wheel arch,roughly where a back seat passengers left/right shoulder would be. Assuming you could ever get a back seat passenger in!!

[Kingme2]

I replace my old, dirty set (3 point) with a new set, and bolted it to my rollbar. Was having difficulty pulling them, angles were too sharp.

I bought a set of seat belt guides from one of our members. it worked awesome. I removed the bolted to rollbar, and hooked them into these new guides. They are steel, and hook onto the headrest posts... WAY stronger than the flimsy plastic original guides. One could likely bend these higher if they wanted extra shoulder clearance, but works fine for me.

[donerehart]

So how do you make the transition from a lap belt to a 3-point system? How have the rest of you done this? After reading these posts, I'm thinking it is something I should do!