Roll bar / harness mount Question

[adrianreeve]

I've also done mine the same way as Ash - great minds and all that!!!

Cheers

Adrian

[jps]

Once again this forum proves a great resource - i'm just working out where i'll fit the threaded bosses in my rollbar cross bar, pictures/info like this is really helpful.

[bentovey]

What are people’s thoughts on wrapping the harness around the roll bar cross brace?

[jps]

Originally Posted by bentovey

What are people’s thoughts on wrapping the harness around the roll bar cross brace?

I've been reading up, so have seen this mentioned. The comments I saw were:
1- You could have the harness run over a round tube and go down to a lower anchorage point. This would make the point where it ran over the round tube the 'effective mounting point' for IVA purposes, so would have to be at the minimum height/sufficient strong (same applies if the belts make contact with the seat when done up).

2 - Top harnesses that were just wrapped (not bolted) onto the cross bar, with no other fixing, might be problematic because they could easily slide side-to-side (either when loose, or in a crash). Couldn't find reference of anyone actually taking this setup to IVA...

[bentovey]

It’s option 2 I was going for. With the shoulder straps wrapped directly to the cross bar. Quite tight wrapping can be achieved with little to no sideways movement. I might put a rubber sleeve over the buckle for iva

[jps]

Originally Posted by bentovey

It’s option 2 I was going for. With the shoulder straps wrapped directly to the cross bar. Quite tight wrapping can be achieved with little to no sideways movement. I might put a rubber sleeve over the buckle for iva

Have you looked at the IVA manual? I had a quick scan and it doesn't make reference to wrapping in the section on Seatbelt Anchorages, but there are plenty of references to bolted fittings (and the required standards for them). Unless you can find an example of someone who has been through IVA with wrapped belts I'd assume you're going to run into problems with it.

You could always use option 1 for IVA and then change how the belts were fitted if you really wanted to (without having to make any structural changes....

[voucht]

Originally Posted by jps

Once again this forum proves a great resource - i'm just working out where i'll fit the threaded bosses in my rollbar cross bar, pictures/info like this is really helpful.

Hi,

That is how I've done it.

2014-08-23_15-51-08 by Voucht sans_nom, sur Flickr

2014-08-23_15-51-28 by Voucht sans_nom, sur Flickr

2014-08-23_15-52-17 by Voucht sans_nom, sur Flickr

There was a general consensus that putting the threaded bosses through the cross bar was a very good solution, and there is no need to use the 3mm steel bracket to fit them on the cross bas as explained in the book. I think a lot of builders did the same as me.

After, concerning my car, I kept the exact transversal position of the threaded bosses as explained page 53 of the book (254mm=300mm=254mm). They don't fall directly behind the harness holes of my seat, as I did my roll bar before buying the seats, and I guess every seat model has its own spacing of harness holes. But it is latterly acceptable, as, IIRC, there is a lateral angle tolerance in the regulation (needs to be checked on your IVA manual)

Then I bought Sabel harnesses. Harnesses need to be the short strap style or single seater type, as the saloon car type have way too long shoulder straps.

Hope that will help

[jps]

I had hoped to add some pictures of my own setup sooner, unfortunately - my seats are a very tight fit and, having painted my seat subframe, i'm still trying to get them fully aligned again - they really do clear with only a couple of mm, so it's a bit of a painful process getting them in!

I'll get it cracked this weekend, then put up some pics!