Hi All
I have my Manta Ray arriving tomorrow, excited does not come close It has a full roll cage and I am looking to fit inertia belts front and back, I may be dreaming or just being stupid...but, does anybody know of a belt that clamps onto the roll cage?

First thing may be a silly question but I assume the cage is suitably bolted to metal and not glass-fibre.

I've only built 3 buggies/bajas but have prepared loads of offload 4X4s, and we normally weld a sleeve through the cage for belt mounts

saying that a quck google did find these http://www.project33.com/article.cfm?ID=951 but don't know if they are street legal

My buggy build is going through IVA eventually so here are the pertinent points with regard to "legal points". Also bear in mind that the IVA requirements are far more stringent than an mot inspection. I leave it to each individual to be happy with the end result of what they have safety wise. A buggy is inherently not the best structure without a full roll cage.

Firstly the requirement is for a 3 point system, not two.
Secondly the tubing needs a reinforcing sleeve for the bolt fixings. The fixing bolt has to be of the correct grade and have corrosion resistance.
Thirdly the height "up the vertical tube that you are going to fit the belt mounting has to be at a specific height that gives the correct belt angle over the shoulder. (It`s important that the lap belt goes over the thigh bone and not the joints. Same with the shoulder belt. Over the collar bone and not the joints.
Fourth.. to be strictly legal a single hoop, as opposed to a roll cage, should have "triangulation". i.e. additional tubes going to the rear and fixed to body with stress plates.

So pick the bones out of that and decide how far you want to go with your set up.

With regard to the retractor.. if mounted on a roll bar\hoop it must be of the type where the retractor is not fixed. That is to say it can move on its mounting so that it can maintain the correct angle for the belt etc.

Hope this helps... Don`t let it frighten you off.   

I am not sure I would be comfortable using something designed to clamp an exhaust weighing a few pounds and not subject to much shock to stop 13-14 stone flying forward in an impact.  Regardless of the number of fitting points in most crashes the strain is unlikely to be evenly distributed.
If the bolt securing the belt needs to be high tensile to prevent shearing then I am not convinced mild steel loops with similar bolts meets the requirements.
Another concern is the contact area of the loop on the cage, it is pretty small and depending on the cage, whether it is decorative or functional, could concentrate the force too much.

Personally if I was to follow this route I would be inclined to make up a more robust loop, possibly more than one for each fitting, and reinforce the cage at the contact point with a sleeve.  If I was going to all this trouble I would probably make a permanent fitting on the cage, drill through and weld in a tube to bolt up to and add some bulk to the cage at that point (not what I have done by the way, my fitments are welded into the main cage as I use full harness)

Just my opinion, but you wont know how well it works until you are either airborne or not, and that is too late

Dave

Thanks for all the suggestions, ultimately this is a safety feature and essential with the kids, I have a local VW specialist (grays garage in Arundel) who also carries out MOT's. I think I shall take it to him as soon as it arrives! Thanks again for all the help

That is a strange one fixed reel on the body and partial rotating on a cage yet the cage is still fixed. If the reel is at the wrong angle you cannot pull the belt out to put it on as they lock up.

Agree with Dave on the exhaust clamps they are not even a known hardness grade just a piece of steel.

There is a tolerance figure quoted in the documentation. The points of all attachment must be deemed capable of dealing with a one ton directional force. (Not put under actual test at IVA but inspecting engineer looks at this particularly closely and makes a visual judgement on what you have).

The rotating rule probably comes out of bodywork being at the side and cages further inboard changing all the angles.

Quote from: Doon L001 on July 18, 2017, 12:36:29 PM
The rotating rule probably comes out of bodywork being at the side and cages further inboard changing all the angles.

Still strange as the rotation is inlne with the car a width change would need a rose joint to get the angles every buggy I have seen with inertia reeels are bolted solid, just had a thought I know of a biggy with a frame that has passed IVA all I need is a good memory to remember to have a look at it.

Surely a well fitted and made cage could be argued as an integral part of the structure and a case made for solid fitment. May need to be welded to the chassis.

Haven't read the rules, life's too short, but there does seem to be a lot that's open to the examiner's discretion

Haven't read the rules, life's too short, but there does seem to be a lot that's open to the examiner's discretion

You are right here..  There is stuff that the manual doesn`t state that you will find an examiner ask for. During my talks with kit car builders it would seem that there is differing opinion\interpretation of things even between two examiners at the same vosa station.

In the end, I guess, these guys have to stick to whatever is put their way for interpretation and do their best to get you through which they do.

I doubt now many buggies will be built to go through iva unless the roll bar & windscreen are left off.

Back in 1974 all I had to do was take body off shell, shorten chassis, attach buggy body. Change V5. Have mot and insure. No problem whatsoever other than the local bobbies stopping you just to have a look see. (Didn`t even need an engineers report). How things have changed.

I think the rotating part must be the shoulder loop.  The design of the go-forward mechanism of a retractor will lock the belt if it is out of its operating zone, so that the belt locks up and holds the occupant in place if the vehicle reaches an unusual attitude, to prevent occupant ejection.  With a rotating anchorage to the retractor, with no tension on the belt the retractor would flop down, taking it out of its operating zone and locking it up.  So you'd not be able to pull the belt off the spool without using a second hand to hold the retractor at the correct angle.

Paul you are right on the changes it used to be the police stolen vehicles squad or motorway patrol coming to check chassis and engine numbers to see if anything was stolen not that it was correctly built