Tom's family 6 point, how did you mount your rear 3pt seat belts?

[barronj]

Where/how did you mount the shoulder strap? I'm upgrading to their custom seats and want to put safety belts in the rear, preferably not just lap belts.

 

[crutch]

I welded in seatbelt bungs for the shoulder mounts. These are the ones I picked up. http://www.bluetorchfab.com/products/btf-seatbelt-bung


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[Glass Pony]

I welded in seatbelt bungs for the shoulder mounts. These are the ones I picked up. http://www.bluetorchfab.com/products/btf-seatbelt-bung


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Same here.

 

[pcf_mark]

I am using this:

https://www.amazon.com/Allstar-ALL60031-Double-Mounting-Hardware/dp/B006K8RNCY

You put the bolt in double shear which is far superior to single shear. Plus the idea of drilling a hole in a ROLL BAR is ludicrous. I will bet any amount of money I know exactly where the bar will fail.

Run the bolt through it put a locking nut on the other side so it is loose enough to swing back and forth.

 

[barronj]

Do you have a picture of how you welded that up? Inline with the top tube or rear corner post?

 

[pcf_mark]

They face forward for the top loop / shoulder bolt. You want the force of pulling on the belt to be through the center not off to one side or the other.

 

[Glass Pony]

I am using this:

https://www.amazon.com/Allstar-ALL60031-Double-Mounting-Hardware/dp/B006K8RNCY

Plus the idea of drilling a hole in a ROLL BAR is ludicrous. I will bet any amount of money I know exactly where the bar will fail.

When I installed the bung I seal welded it on each side of the penetration. While it may not be NHRA approved I felt it was a lot better than what the instructions called for as they said to drill a 1/2" hole through the roll bar and fasten it with the 1/2" grade 8 bolt and nyloc nut. Then the more you tighten it you crush the roll bar.

 

[ntsqd]

Not uncommon at all to drill a hole in a cage and weld in an insert. To universally state that those locations are where the cage will fail is assuming too much. So long as the sleeve OD isn't greater than about 1/4 of the tube OD, and the sleeve is placed on-center in the tube doing this doesn't significantly reduce the strength of the tube. NHRA may not like it, but then they also allow 1-5/8" tubing for cages in heavy cars! I wouldn't place too much faith in their rule book until you understand the whole context of their rules. Not all sanctioning body rules are based in science or rational thought. One required hose clamps on Push-Lock/Barb-tite hose ends, even after they were presented with the page out of the mfg's catalog that specifically said NOT to use hose clamps on these fittings!

I prefer a tube that I can use a thru-bolt and a nut with rather then those that are threaded as that makes locking the assembly easier. The interwebs places too much emphasis on everything being designed in double shear. A well designed single shear install can be far stronger than a poorly designed double shear install, and believe me, I've seen some exceedingly poor "double shear" fabrications.