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Roll bars and seatbelt mounts
luke - 6/1/10 at 05:10 PM

Im looking into roll bars now, i want a full roll bar across the car with two backstays.

OBP do one, but they also make custom bars and cages. Would it be wise to get a second bar accross the roll bar, say about a 1/3 of the way up for seatbelt mounts?

thinking i can kill two birds with one stone here.

Miks15 - 6/1/10 at 06:40 PM

i bought an OBP one, but only the single hoop no back stays or crossbar. I then bought some tube the right size and made my own back stays and cross bar and welded my mounts to the cross bar, you can see the hoop, back stays and cross bar here


luke - 6/1/10 at 06:45 PM

you going to use the crossbar for seatbelts?

EDIT doh, just reread ur post!

[Edited on 6/1/10 by luke]

JohnN - 6/1/10 at 10:36 PM

Just like these? Threaded inserts fully welded both ends in the crossbar. However, Shrewsbury tester wanted protection from the finished result
Harness Mounts
Harness Mounts

luke - 6/1/10 at 10:38 PM

quote:
Originally posted by JohnN
Just like these? Threaded inserts fully welded both ends in the crossbar. However, Shrewsbury tester wanted protection from the finished result
Harness Mounts
Harness Mounts


Exactly like that.

What did he want protecting? the eyes?

kennyrayandersen - 7/1/10 at 06:36 AM

OK, so I’m stupid, but what are you using those eyelets for, it that the seatbelt attach point? They do seem awfully tall. If there is any lateral load (critical would likely be forward crash) there is a huge bending moment at the base due to the height. It’s likely I’m missing something.

scutter - 7/1/10 at 07:20 AM

I'd say those eye end fittings have yet to be screwed in!

ATB Dan.

kennyrayandersen - 7/1/10 at 02:43 PM

quote:
Originally posted by scutter
I'd say those eye end fittings have yet to be screwed in!

ATB Dan.


I'm hoping that's the case otherwise, speaking as a stress analyst, it don't look so good.

Better would be to used a standard high-strength bolt and a seat belt plate (like is installed in pretty much every car made). That way the load get transferred directly into the beam with no bending.

[Edited on 7/1/10 by kennyrayandersen]

JohnN - 23/1/10 at 08:29 PM

The eye bolts were not screwed in - obviously - !

With apologies for the size of the picture...........

This shows the protection I had to add to shield the belt clips (that connected to the eye bolts) from any unwary pedestrian, should I reverse and hit them!

Rear view
Rear view

Angel Acevedo - 24/1/10 at 11:24 AM

quote:
Originally posted by JohnN
The eye bolts were not screwed in - obviously - !

With apologies for the size of the picture...........

This shows the protection I had to add to shield the belt clips (that connected to the eye bolts) from any unwary pedestrian, should I reverse and hit them!


YOU MUST BE KIDDING!!!!

GonzoRacer - 29/1/10 at 12:07 AM

Hi-
I'm kind of new here, and not familiar with UK road and racing regulations. Looking at the eye-bolt mounts and reading the issues with getting them certified, I had to wonder if "wrap-around" mountings were legal there?

The blue belt in the attachment is an example.

Would those work for ya?

JD Rescued attachment wraparound.jpg
Rescued attachment wraparound.jpg

luke - 29/1/10 at 12:24 AM

not sure, but looking at them theres not much stopping them sliding up and down the bar, dont think i would trust them!

Fozzie - 29/1/10 at 12:26 AM

Hi Gonzo....and a big welcome to you......

Sadly, that method is not allowed here in the UK...

The rules and regs here for both 'road' and 'race' are pretty tight......as safety is the issue here, it's not a bad way to be.....

John please reduce your picture..it is about 3 times the size it should be!

Fozzie

GonzoRacer - 29/1/10 at 12:37 AM

I understand, and if it's not legal, point is moot...

The "wrap" mount is used for competition shoulder belts mostly, and attaches to the (required) horizontal bar in the main roll cage. They don't slide much, and if they do, you can usually stop it with a nylon "tie wrap" around the bar to limit the belt moving.

There is a specified way to wrap the belt thru the buckle, so as to lock it in place.

It's solid, and safe, just not legal in the UK.

But, hey, I'd been a member for about 12 minutes and just had to post SOMETHING!

Regards-
JD

Fozzie - 29/1/10 at 01:09 AM

Absolutely Gonzo...

Post away.........It's great to 'see' you!

I do understand the 'method' by the way...

It's just not a good idea (I believe) for all of the weight/strain to be in one place.....

JohnN is, by the looks of it, fitting or changing post SVA/IVA ?

It is better IMHO, to fit the correct high tensile bolt through the horizontal bar and then top rail of the chassis .....it spreads the load, and doesn't rely on one structure to take the load....SVA man liked it.....

Here is a picture of mine.....you can see the off-set of the bots through the horizontal bar to chassis, and the fixings for the harness....
so the load is spread along the bar, then from the off-set through the chassis rail.....

I have had to lighten the picture as it was a bit dark.
Description
Description

Fozzie