Rear Upper 4 Point Harness Fixings

[Guest Jonathan.Ritchie]

Good Morning..

 

Just a quick one.

 

I currently have 1 steel tube per side attached to the chassis for fitting the shoulder strap sections of my 4-point harness.

 

Is it ok to bolt both straps to this 1 mounting point or would I need to get 2 individual fixing points for the harness.

 

If so does anyone know where I could get a few more of the tubes for fixing the harness?

 

Cheers

Johny

Edited December 7, 2015 by Jonathan.Ritchie

[fry61]

Quicker reply --- picture required -- should be 2 per belt.

[richyb66]

Single fixing is ok as long as when the harness is under load, it doesn't pull tight on the seat and put load into the seat frame.

 

As Bob says, pictures would help and 2 per belt will probably give you a better chance of not loading the seat frame.

[Guest Jonathan.Ritchie]

Yeah sorry I'm at work so can't get a picture just now.. I'll try and see if I can get the old photo's of the car off facebook before I bought it.

[Guest Jonathan.Ritchie]

I've got an old picture but struggling to get it uploaded.

 

what's the best way to load pictures on the forum?

[Guest Jonathan.Ritchie]

looking at the photo the fixing tube is definatelly more in line with 1 side of the seats than the other. I would say that I would be much better running 2 of the fixing points and t=getting another tube welded to each side to get 2 for each belt.

 

I have the stainless chassis, where would I get the tubing from or could I use a piece of 316 stainless steel instrument tubing?

[Guest Ian & Carole]

 

This is as mine passed SVA in Beverly in 2003 but they initially failed it, insisting the tube be fitted into the upper rail and not welded to the rear of it as per the factory fitting.

 

IIRC Ian Marrs', I was there so am pretty sure, also passed IVA this year with the same condition, that he re-fitted the tube into the rail and not welded to the back of the bar of the chassis again not as it left the factory.

HTHs

Edited December 7, 2015 by Ian & Carole

[Guest 2b cruising]

With the 2b chassis from the factory as in the one I just assisted with.

There were two vertical fixing tubes per side, fitted to the lower horizontal bracing tube of the roll bar.

The possition of these had to be altered to avoid the belts fouling the shoulders of the seats when worn.

Others I have seen have been left original because of different seat designs.

Personally I would always use one per shoulder strap.

Not only would it avoid possible strap chaffing on your neck. It also spreads the load.

As long as the tubing is painted correctly after fitting, it would not matter using mild steel. It will weld to stainless.

[Guest Ian & Carole]

With the 2b chassis from the factory as in the one I just assisted with.

There were two vertical fixing tubes per side, fitted to the lower horizontal bracing tube of the roll bar.

The possition of these had to be altered to avoid the belts fouling the shoulders of the seats when worn.

Others I have seen have been left original because of different seat designs.

Personally I would always use one per shoulder strap.

Not only would it avoid possible strap chaffing on your neck. It also spreads the load.

As long as the tubing is painted correctly after fitting, it would not matter using mild steel. It will weld to stainless.

That would have been one of the later chassis, all the early ones only had one tube each side as in my picture.

 

Drove 15K spirited miles with that set up and never had an issue with chaffing.

Edited December 7, 2015 by Ian & Carole

[agent_zed]

just thinking out loud but i would think that a three point system like this versus a normal car 3 point system would still take less load on the mountings in an accident. In the retracting type setup of a normal car you would likely have momentum before the belt stops you so the dynamic loading is going to be greater. Assuming you have strapped in tight-ish with the static type belts you won't have much movement before the belt takes your weight so the shock to the mounting should be far less.

 

The belt will also be pulling at a better angle on the bolt as it will be inline whereas in a normal car the belt will be pulling at an angle on the top mount on the door pillar.

 

might be wrong but hopefully you see my logic for thinking it so

[Guest 2b cruising]

Keep thinking mr zen.

May the thoughts be with you.

Seriously, your logic abounds in a good way.

[Snapperpaul]

I see your logic Zed however the forces increased by the mass ( your body) moving a few mm is trivial compared with your internal organs moving forward within you in a high g crash

It's at this point I think we are just trying to more clever than our understanding of physics allows

[Guest peter2b2002]

My 2b has two tubes about 1foot apart I think some 2bs had 1 fixing point behind the seats for a 3 point belt

Peter2b

[Guest mower man]

My sternum and Stella's were broken in a head on ,I had a thick body warmer on at the time and self tensioning belts ,cant prove anything but I think neither helped full harness must be better

[fry61]

4 point must always be better than 3 -- but the inertia reel 3 point is always correctly tensioned to the body -- how many ensure the manual adjust 4 point is always a snug fit -- journey out is in the cold & return is warm & clothing has been shed -- have you adjusted every time?

 

Hopefully Mike & his lady don't test the belts in the future -- as we all wish for ourselves.