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I have a disagreement with a pal. I run the passenger seat in my car bolted down only at the front, as I often remove it to put stuff in its place (2 seater car).
A pal thinks any head on crash will result in GUARANTEED DEATH due to the seat not being bolted down at the back
I think it won't matter much - it only adds 10kg to the weight, doesn't articulate forwards much and you are stopped by the seatbelt in any case, which is specc'd for fat people.
WHO IS RIGHT ❓
Only one way to find out......
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just imagine the seat hitting you at 70mph in a crash........
you are stopped by the seatbelt in any case, which is specc'd for fat people.
i'm no expert but i'd suggest any calculations made in 'stopping fat people' take into account the seat being bolted down in all 4 corners.......
I'd say that it'd be GUARANTEED DEATH (in a fatal accident)
you are stopped by the seatbelt, shortly followed by the seat being stopped by your spine
just imagine the seat hitting you at 70mph in a crash........
I can't - how would that happen exactly?
well, take two bolts out the drivers seat and see if you feel less safe.
also, you're assuming a headon collisison - side impact might be more likely to make the seat move in ways it wouldn;t with 2 more bolts.
Al is - the seat won't "hit" you as it is already in contact ( think push not punch) - you will get squished between the seatbelt and the seat so it will increase risk of injury but not by a huge amount. I would ride in it without worry ( unless al was driving of course when I would shite myself)
I would be worried about police / insurance and vehicle not in roadworthy condition tho. MOT failure / insurance not valid
MOT is no guarantee of safety though
Your problem is that your seat will now pivot under its own mass, this will load the front bolts in bending and possibly much more in tension than designed, as they're normally designed to be loaded in sheer (seat is now pivoting about an external point away from the bolt, like the front of the runner) which could well vastly reduce the strength of the bolt and/or pull the other side through the support metal in a peeling motion.
Imagine holding a bolt between your oustretched fingers, grab the bolt near your fingers and try to pull it through your fingers in the same plane as your fingers - fairly easy to resist. Now grab the top of the bolt and attempt to bend it over and pull it out like a claw hammer does with a nail - which is easier to hold on to? Once the seat is free to move, the various assumptions made in the safety checks are invalid as the body is free to move sideways and could rotate sharply if only one bolt fails.
I'd not be driving with you. Doubt it would cause death necessarily, but it wouldn't help in an accident, and probably would make injuries more severe.
Is the seat belt located onto the base of the seat or the transmission tunnel. If on the seat then it is very unsafe (MOT failure ),If on the transmission tunnel then not nearly as unsafe
Your mate is right
I'm with your mate, and coffeking, potentially dangerous. Probably invalidate any claim in a crash...
Incidentally, I dont know your car but my car seats are way > 10kg, but they are electric everything.
Don't crash.
Problem sorted.
But how does the seat actually move significantly (i.e. enough to chear a bolt) when the passenger is wearing a seatbelt? (and of course that's not bolted to the seat!)
Well if the seatbelt is totally independant of the seat then I think it would be reasonably safe to sit in (well safer than some of the cars from yesteryear with rotten floors and bolts that used to be driven around)
cynic-al - you're assuming that the only force acting on the seat is it's own weight.
seats are desinged so that in a crash the weight of the passenger is forced down into the base (to stop you sliding out under the lap belt). So, in essence, you have the weight of the seat, plus the weight of the occupant on the bolts (seat belts have some 'give' in them and again, tend to direct force down into the seat).
and in a side impact parts of the car maybe pressing on the seat and pushing it towards the middle of the car.
In summary;
I wouldn't want to explain to my passenger why they were now a paraplegic or to their family why they were dead because I couldn't be arsed to put two bolts into a seat mounting.
Seat manufacturers spend a fortune to stop "submarining" in crashes. I guess that's because all manner of strange forces come into effect.
But saying that, my old Triumph Heralds, Beetles and Reliant Scimitar both had seats that were hinged at the front to let the passengers out. Nobody died. Only one front-end shunt though.
Get it sorted lad!
wwaswas - MemberIn summary;
I don't really know
fair enough
I would say you could also be found guilty of some crime or other (in the event of death/injury) by allowing someone to passenger in a seat with half of its fixings removed.
I wouldn't sit there.
I was trying to keep it freindly, as per the thread title.
If you'd like the unfreindly version;
If you knowingly drive around with an illegal car you should have your licence revoked
In this case your car has construction and use for seats with 4 bolts, you've chosen for the sake of convenience to take a chance on 2.
you going to be runnign your boiler with no cover on tonight and the window open a abit ' to let the CO out'? I'm sure it'll be fine.
Is the car on a conveyor belt?
Big John - the base of the Beetle seat is fixed to the floor, via the runners, by 4 bolts. The flip forward happened at a hinge at the base of the backrest, not by tilting the entire seat forward on a hinge at the front.
Car manufacturer spend a lot of money on reducing costs - if they could have removed those two essential rear bolts to save design effort and money they definitely would have.
I would definitely not get in a car with you.
Same on a triumph herald - there were 4 bolts holding the seat base down (I had to undo them enough bloddy times to get at the gearbox and overdrive...)
I think any outcome of a crash can be speculation other than saying that 2 bolts arn;t as solid as 4 bolts...
The only thing you can gurantee is that the insurance company would not pay out in the case of an accident. They are slimy ****ers and any excuse not to pay a claim they will jump on.
If you hit a £20k and the insurance doesn;t cover you are liable for all monies owed to the other driver, including compo, so on that basis alone I wouldn't feel comfortable driving it
I think I agree about the VW, but the Herald definitely pivoted at the front. But it did have a 4 bolt subframe.
I agree it pivoted but it was bolted down in 4 places to spread the load.
Keep yer wig on wwaasssaawwwasss!
Anyone [u]know[/u] if this would invalidate insurance, fail MOT etc?
Al - given that the seat mountings are checked as a part of the MOT and if the seat is not secure it is an mot failure I would be very surprised if it did not count as a vehicle in unroadworthy condition
"Seats
The driver's and the front passenger's seats must be secure.
All seat backs must be securable in the upright position. "
secure means held down by all the bolts the manufacturer intended, not relying on the seatbelt and the passenger to stop them flying about in an accident.
wig reapplied, thankyou.
Well it shouldn't have passed the last MOT then OMG111
There's dog-poo in your wig 😛
Bad MOT tester then - its clear seat mountings should be checked.
Remove 2 bolts from your stem faceplate, I'm sure you'll be fine.
But how does the seat actually move significantly (i.e. enough to chear a bolt) when the passenger is wearing a seatbelt? (and of course that's not bolted to the seat!)
Because car seats are pretty heavy and the negative accelerations involved in a crash are pretty damned amazing, meaning anything not securely bolted down becomes a pretty good weapon. Like I say, it's not going to be a guaranteed fatal accident, but it certainly isnt unimportant in the equation and I couldn't look my passenger in the eye if there was an accident and they were injured more than needed by my laziness.
2 bolts take 1 minute to re-install. You're willing to risk additional damage to your passengers for 1 minute every so often? I hope you do warn each of them before they get in?
Are you a hairdresser?
That seat had 4 bolts put in at the factory for a reason, i am with your mate. 😉

