Stag Rear Seatbelts

[Biffo]

Here's another newbie Stag owner question. I want to put rear seatbelts in the Stag (its a Mk2), and as my kids are young (7 and 3) I want to fit inertia 3 point belts as they are safer and hold the booster seats in better. Rimmers list 3 point inertia belts, so do HRS. When I called my usual supplier, Robsport, they said they cannot get rear 3 point inertia belts to fit and work properly so only recommend static lapbelts. What are other Stag owners experiences ?

[Spitfire4me]

I recently fitted 3 points in my Stag. The reel rolls out from the side through the side pocket (where two points lap belts would go as well). They do foul up a little and take time to return but I havent yet fully cut back the trim and stuck it down neatly.

They do work ok and are better than lapbelts. however people expect to draw the belt over the shoulder rather than from the side!

Fitting is straightforward enough. You dont need to remove the rear shocks fully to drill the top mounting int the shock strut; just undo the top mount and pull the shock down out of the way. Nimble fingers required to get the bolts etc in!

Still very pleased to have 3 points in the back tho. My kids are 5 and 7 so its perfect with booster seats. Let me know if you want any further advice.

[shenderson]

Tricky, especially regarding child seats and booster cushions - and experienced as a seat belt and accident investigation consultant.

3 point belts are undoubtedly better than 2 point belts, but I would prefer a sound 2 point installation over a poor 3 point one every time.

Rear seat belt mountings are provided in all Triumphs, and in the Stag they are for 2 point belts only.  However you can be sure that, if the surrounding bodywork is sound enough, they are at least strong enough more or less correctly positioned.  If the mountings are incorrectly placed the seat belt webbing can cause serious injuries in during a collision.

There is no structure that I would consider strong enough higher up on the Stag to support an upper anchorage  - if the webbing is simply looped over the rail behind the rear seats and anchored to the floor or wheelarch, the rail will simply fold forwards during a frontal crash.

On balance, I would go for the 2 point, but it must be worn correctly to preevent abdominal injuries - tight across the pelvis and underneath any thick or loose jackets etc (same applies to 3 point belts).

The problem is with booster seats, which are for precisely the problem I have mentioned - poor belt geometry.  Seat belts are designed for adults; childrens' bodies do not fit in them correctly and, without a booster seat, the lap belt rides up across the abdomen during a crash - often with horrendous results.

The safest thing to do is carry the child, correctly belted in a booster seat (or child seat, depending on age) on the front passenger seat - an adult will be less vulnerable in the rear with just a 2 point belt.  As long as you only have one child...

Sorry, that's the best advice I can give, there's no easy answer.

Regards

Steve

[Spitfire4me]

All good points but the upper suspension mount (not floor) is at least 2 skinned and strengthened for the suspension. It is at least as strong as the plates already in the car for the other two points being reinforced with s[pot welds. Thats more than the other two points. You also use a wide plate to spread the pull.

When you buy the belts the instructions show what you have to do.

I certainly wouldn't and don't have any worries in that respect. Just be sure that your suspension tops are rust free as well as the other two points.

[shenderson]

I guess the suspension top mount you mention is the upper damper mounting?  If so, I'm sure it's probably strong enough but the webbing would still have to take an indirect route through a guide on the floor (to avoid the hood when it's stowed) and then up behind the back of the seat.  The actual crash loads would therefore still be taken by the seat back.

However I haven't seen the installation, maybe there's a way of doing it without these problems.

Steve

[Spitfire4me]

Must have alook Steve. I did them myself and didnt notice any problems. There is no guide and it doesnt appear to be trapped anywhere! Tell you what I'll take a photo. The hoods up at the mo so should be difficult. The reel is behind the side pocket of course

I'll be back....

[Spitfire4me]

Here you go! You will see the arrangement hopefully. When the hood goes back it actually misses the belt. It is approximately parallell with the stowed hood. Clearly if the hood pushed down on it then at least some strain would be diverted to the top of the seat frame.

Do you think it is ok all in all?

[Spitfire4me]

close up

[shenderson]

I'm afraid, from what I can see here, the answer is no! (although it is better than no seat belt, especially in a soft-top car...)

This set-up might be OK in low severity collisions but, once things get more serious, I can see problems.

The anchorage below the damper mounting might be strong enough but a severe frontal crash will cause the webbing to load the top of the seat frame vertically downwards and it will simply collapse.  That will have two effects:

1 - it will increase the length of webbing around the occupant, effectively lengthening the lap part of the belt and allowing excessive forward movement of the occupant

2 - it will force the occupant's shoulder vertically downwards, possibly crushing the spine

Also, without an upper guide, it won't be much use securing a child seat in an impact to the opposite side.

The only way to make this work is to reinforce the top of the seat frame to prevent vertical collapse, and fit a guide to position the upper run of webbing correctly.

Who is the manufacturer?  Are there any approval markings on the orange label?

Sorry to be purveyor of unwelcome news but, better to know now than when it's too late.

Regards

Steve

[Spitfire4me]

Well it is that well known securon set and is sold for stag rear seats with instructions. All the main suppliers sell it.

The seat is actually bolted to a frame which iteself is welded to the floor on  two sort of a frames. It is a sunstantial frame really and guess is part of the need to stop the car flexing without a roof.

It seems to me that the seatbelts are being incorrectly sold by your view and are not fit for purpose.

Lets say that the frame for the seat is strong enough, when you say guide you mean an oval to keep the webbing in place?

may I discuss this with you by PM as this is not really satisfactory this way! If you look at www.rimmerbros.co.uk you should see pics of the seat frame.

[Spitfire4me]

Looking at the pics, you can see the shape of the seat frame follows the seat shape thus giving more strength. It appears to me that it would be difficult to collapse the seat frame. So the only prob would be a guide for the webbing. Any ideas for that?

Would Securon have done a survey on a Stag to satisfy themselves?

[shenderson]

I'm familiar enough with the seat frame - it took me three years to rebuild my Stag!

As I have said, there are a number of problems with this set-up; I have no idea how Securon have designed and tested it but they are unlikely to have done a crash test!

It makes sense, as you suggest, to discuss this outside the forum and maybe post any conclusions, decisions etc at a later date.

I haven't got your number; any chance you can call me over the weekend? 0121 243 1780

Steve

[Spitfire4me]

Thanks Steve. Will try and remember to call you!

[SimonD]

Hi. If you came to any further conclusions or had discussions with the manufacturer on this subject I would be very interested to hear.
Thanks
Simon

[Spitfire4me]

I did go to the website and the Stag is simply not listed. Shenderson is an expert in the field and doesn't feel comfortable with 3-point belts as the car was not designed for them. It has 2 point mounts and thus he feels that is what you should fit.

The other side of the discussion is that all the main triumph people supply 3 -points for the Stag with full fitting instructions!

It's a tough one. It is really the trouble with the third mounting point (suspension turret) but rather that the belt from it passes over the back of the seat. Consequently it is deflected at that point and in an accident may take some downward pressure on the seat frame that it wasn't designed to take.

In my case the deflection seems so slight that I struggle to agree that any downward pressure is or would be present although I can see the argument.

Frankly I am of the conclusion that 3-point is better than 2 on the basis that with 2 point in an event of an accident the occupant would be tossed about whereas with 3-point they would not even if the seat back should bend. In that ( I feel unlikely) event there is the possibility of not being retained by the belt as it slackens.

Probably not much help as the answer is: The choice is yours!

[SimonD]

I haven't got a Stag at the moment. I'll have to pop along to a show to have a closer look. I understand the downward pressure on the seat frame but I don't see how the belt is stopped from slipping over the top of the seat back (surely a more direct path from it's mounting point on the inner arch). Is there some trim or a mounting that I cannot see?

Apologies for my ignorance of the cars - I am weighing up the practicalities of owning one.
Thanks

[Spitfire4me]

The belt goes over your shoulder to the catch so is a direct line from turret to catch as it happens. It is comfortable and seems to be no touble.

Practicalities of a Stag! Well 4 seater V8 convertible and or coupe with hardtop couldnt be better. They start and run easily. Cheap to insure when garaged (118.20 for me and the wife on 6,000 miles) no tax on my 1972 so that offsets the extra fuel cost!

If you get a Stag you cant get that V8 out of your blood. They are very comfortable riding all the bumps with ease. Electric windows etc all add to the easy living with a Stag.

Any questions then pm me.

[shenderson]

Sorry I've not been in touch, been a bit busy!

I had a look at my car at the weekend, in particular at the relative height between my shoulder and the top of the rear seat back.  My shoulder sits a good distance proud of the seat back (I'm 5'11") so compression would be a problem if a lap shoulder belt was fitted, regardless of whether the seat back crushed during a collision.  However the Stag is no worse in that respect than a Spitfire and even several modern convertibles.

This is unlikely to be a problem for children and anyone who's shoulder sits lower than the seat back, except in a very severe collision that crushes the seat back.  The lighter weight of a child would require a more severe collision than a heavier adult to crush the seat back.

There still remains the problem of locating the shoulder belt laterally as the kit does not include a guide at the top of the seat back.  This is important for side impacts, to prevent the occupant moving across the car.  On the face of it the 3-point installation is no worse than the 2-point, lap-only belt.  However the 3-point set up will force the occupant's shoulder downwards as he/she moves across the car, compressing the shoulder and spine.

Therefore I think a guide should be developed to locate the shoulder part of the 3-point belt at the top of the rear seat back.  Obviously it would have to clear the tonneau cover so it may be no easy task.  Ideally the seat back should be reinforced in the area where the guide is mounted.  In this way it ought to be possible to effectively secure child seats in the car, but the 3-point belt still does not seem to be suited to adult occupants.

I hope this helps

Steve

[Spitfire4me]

Thanks Steve. been an interesting exercise.

I will have a look at the guide issue as well although i cant see the difference between some modern cars where the belt comes in low over the rear seats from the boot area.

There is a bit of room under the tonneau for a short locator but I think we all agree we are thinking of just the kids in the back really!