Estate car 3rd row seats & crumple zones - SjB {P}
I have heard many a person say they would never put their loved ones in an estate car third row of seats for fear of putting them in the crumple zone. Thinking rationally about this, I thought there is probably design legislation to prevent placing occupants in a crumple zone, and in any case, even putting morals aside, the likes of Volvo, who offer such seats as an option on the V70, have too much of a safety driven reputation at stake to do it.

Sure enough, recently speaking to a dealer I learned that this is so; In the same way that in many car designs front impact forces are passed to the rear of the car to avoid crumpling the passenger cell (look at crash test photos and you often see deformed rear panels from a frontal impact) so the same is true of the rear of a V70; instead of crumpling, rear impact forces will dissipate forwards, in the process deforming the outer body shell along the flanks of the car, whilst bending the rear floorpan as a unit.

A friend here in Sweden was unlucky to be rear ended big time on the E4 motorway in his V70 and bears the dealer's belief out; although the insurer scrapped the car after assessing the damage, he had been able to drive the car home afterwards - a 150 mile drive - because the rear wheels were unfouled.

He didn't take any photos, but by chance I just found a photo that shows what happens; tinyurl.com/y7ylas

No doubt other "third row seats possible" cars have similar approaches to safety.
Estate car 3rd row seats & crumple zones - Happy Blue!
Wouldn't be overly happy to drive that red V70 for 150 yards let alone 150 miles!
Estate car 3rd row seats & crumple zones - Clanger
Good work Volvo!

I think some of the adverse comments refer to aftermarket modifications e.g. using the rear loadspace to put a set of Motorhoods rear seats in. I don't think there is any legislation to stop someone using the estate car rear load area as a place to put seats. Ten years ago, with a Citroen XM hatch which I was really enjoying, the arrival of child 4 made me think of swapping the XM hatch for an estate and fitting Motorhoods rear seats to it. I didn't and got a 7 seat Volvo 760 with rear-facing seats. None of the family got on with the Volvo so I bought a 7 seat Synergie instead.

Your friend is brave to have driven his Volvo 150 miles like that!
Hawkeye
-----------------------------
Stranger in a strange land
Estate car 3rd row seats & crumple zones - adverse camber
Having just spoken to various people about rear seats (I volunteered to take children from the local primary school to a concert) I discovered some interesting things:

1) the factory fit rear seats in a V70 ARE approved child seats.
2) the factory fit rear seats in a merc E class are NOT approved child seats and should only be used by adults.
3) rear seats in porsches are not approved child seats and a suitable approved booster must be used - Try finding one.
4) the expert responsible for this stuff at the Dept of transport drives a lotus 2 seater.
Estate car 3rd row seats & crumple zones - daveyjp
Does the Picasso have a third row of seats? I followed one yesterday with two children sat in the boot area - to say they looked vunerable is an understatement.
Estate car 3rd row seats & crumple zones - Xileno {P}
"Does the Picasso have a third row of seats?"
The old model doesn't. I think the new one does.

(New Picasso test at www.honestjohn.co.uk/road_tests/index.htm?id=256)

We had a number of seven seaters as a family, 504's, 505's and last a Renault 21. All were good workhorses, although the 21 felt a fit more flmsy than the Pugs. Back in those days we didn't know otheriwse but everything one does is full of risk. I would be far happier in the rear seats of a strong car such as a Volvo rather than in any small car.
Estate car 3rd row seats & crumple zones - Cliff Pope
In my experience (two rear end shunts at quite low speed) a Volvo's crumple zone is in the car behind anyway.
Estate car 3rd row seats & crumple zones - bignick
As far as I remember Audi withdrew the optional rear facing seats from the series 2 Audi 100 Avant (still one of the loveliest looking estate cars ever) for precisely this reason.

Quite agree about the Volvo crumple zone - my 740 estate was rear ended - wrote off the other car - I had to buy a new chrome cover for my towball and have the bumper cover repaired.
Estate car 3rd row seats & crumple zones - Aprilia
Car manufacturers have put effort into making the front of their vehicles crumple - not the back. The front of a modern car is fairly 'soft' and designed to crumple so as to limit the maximum deceleration of the occupants and increase their chances of survival. For that reason even a fairly minor impact will cause some deformation of the longitudinal chassis rails - couple that with lots of expensive and delicate parts at the front (headlights, a/c condensor, radiator etc etc) and it is easy to see what a modest front end impact will cause the car to be an economic write-off.

In constrast, the rear of most vehicles is fairly stiff. Having seen many rear-ended vehicles over the years I notice that often the back end stay largely intact but you get a chassis deformation right above the back wheels (where the chassis has a 'hinge point') and sometimes a crease in the roof too. If a towbar is fitted then the energy tends to be transmitted further down the chassis and this can introduce a barely-noticable 'tweak' into the chassis. For this reason it is a good thing to have chassis alignment checked after any kind of significant rear impact - even if little obvious damage appears to have been done. The comment about the other car 'being the Volvo's crumple zone' is a good 'sound bite' but it is not true.
Whether the ridgidity of the rear of the car is a good thing or not is debatable, it is transmitting energy to the occupants rather than absorbing the energy. This could have nasty implications in the case of rearward facing 3rd-row seats. A lot depends on the exact circumstances of the accident.
Estate car 3rd row seats & crumple zones - IanJohnson
I remember seeing something from Mercedes a few years ago when they said you needed two feet (metric version) to create a crumple zone.

The implication is that there is no rear crumple zone in many cars (not measured by Ncap so not done).

Not so bad if you are facing forwards and have the support of a seat back but would not like to be in a rear facing seat!

For those who commute by train the suburban trains built in the last 10-12 years have crumple zones at each end, the last row of seats is IN the crumple zone - I would not use them! Still better than the old slam door trains which were one enourmous crumple zone!
Estate car 3rd row seats & crumple zones - Cliff Pope
The comment about the other car
'being the Volvo's crumple zone' is a good 'sound bite' but
it is not true.
Whether the ridgidity of the rear of the car is a
good thing or not is debatable, it is transmitting energy to
the occupants rather than absorbing the energy. This could have nasty
implications in the case of rearward facing 3rd-row seats.
A lot depends on the exact circumstances of the accident.


And on the relative weights of the cars. In each of my two examples, a smaller car ran into my back at about 20 mph - I was stationary.
I hardly felt a thing, but thought I had better get out and look. One car had a crumpled front bumper and smashed lights, the other likewise and the radiator bashed and pushed against the engine.
Annoying about the scratch on my tow ball cover though.
I don't know how strong the front "crumple zone" is supposed to be - strong enough to withstand my wife driving into the back wall of the garage anyway.
Estate car 3rd row seats & crumple zones - jc2
Just remember that in many of these vehicles,the rear row of seats,approved or not,are sited directly over tth fuel tank!!!
Estate car 3rd row seats & crumple zones - SjB {P}
Just remember that in many of these vehicles,the rear row of
seats,approved or not,are sited directly over tth fuel tank!!!


Big deal.
With few exceptions, so are the second row occupants.
Estate car 3rd row seats & crumple zones - mss1tw
If a towbar is fitted then the energy tends to
be transmitted further down the chassis and this can introduce a
barely-noticable 'tweak' into the chassis. For this reason it is
a good thing to have chassis alignment checked after any kind
of significant rear impact - even if little obvious damage appears
to have been done.


Where would this be done, and is it likely to have been done as a standard repair?

My car was rear ended during it's previous ownership, the guy was totally honest and had bills for the work, the tow bar had new bolts which makes sense but is there a legal requirment for them to do this?
Estate car 3rd row seats & crumple zones - mss1tw
I should add the work was carried by SEAT themselves and apparently it was a very minor accident. ISTR the work came to about £1000.
Estate car 3rd row seats & crumple zones - Aprilia
There is no legal requirement. The repair just has to be done to the satisfaction of the customer and, of course, the vehicle has to pass the MoT. There are lots of vehicles running around with chassis tweak due to poor accident repairs.
Ideally the car should go on a jig, e.g. a Dataliner with laser measuring system. You then clip targets to various chassis alignment points, as shown on the screen (the software guides you through) and the software tells you if anything is in the wrong place. Takes about 30-40mins to set it up and obviously if anything is out of place then it will need pulling into alignment.
Usually the bodyshop manager will make a judgement from experience on whether it needs checking or not. People talk about measuring the distance between wheel centres, but to be honest that only shows gross distortion.
I must say that if your rear impact bent the bolts holding the towbar to the chassis then it must have been a fair whack
Estate car 3rd row seats & crumple zones - mss1tw
I think it's more due to the high tensile steel and sudden impacts (?)
 

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