Date: Fri, 21 Jan 2000 15:13:55 GMT From: carrutnnopsameja.com Subject: Re: 9-5 Structural failure WEB site
In article <869e65$ov5$1nopsament13-gui.server.virgin.net>, "Matt" <m.faulksnopsamin.net> wrote: > > | If you look at the picture second from the left (large format), you > > | will see at the right hand side, behind the rear wheel, that there > > | is a tyre track which has been punched through the pebbles covering > > | the drive, down into the soil below. That track is 2 to 3 inches deep. > > | That happened when the back of the car, weighing between a quarter > > | and half a ton, collapsed onto the tyre/wheel. > > > > Are you saying that just because the suspension failed that the > > weight on the wheel suddenly increased so much so that the wheel > > "punched through the pebbles" to a depth of "2 to 3 inches"? > > -- They asked me for an account of it. So I offered them my thoughts, in the absence of any definite knowledge. It seems to me a remarkable coincidence that the muddy mark there is in close alignment with the scoop in the drive, and that same muddy mark is in the same place as the sidewall damage. I reckon I was hoping SAAB experts would have some comment to make on it. So, do you have any idea what to expect when you reverse a car up onto its rear wheel when said wheel detaches itself from the trailing link ? I have no practical data on that subject. To me it sounds a lot more sensible than 'your sidewall has some damage therefore your suspension snapped with no other damage apparent to other components in the same load path'. > > | Now, the damage to the tyre wall is co-incident with the mud, that > > | part of the tyre which was forced through the pebbles, suddenly > > | and with a lot of force. The bulge on the tyre appears to be a similar > > | size to the pebbles covering the driveway. It seems to me that > > | the tyre, deformed grossly from its usual shape, and being plunged > > | through a few inches of pebbles, was somehow checked against the rim > > | of the wheel, and perhaps one of the little stones. > > > > You must be pulling our legs -- the tyre "deformed grossly" and > > "plunged through a few inches of pebbles" by some magical force? > > The weight of the car (as seen by the tires) did not change > > so dramatically just because the suspension broke. There is a downwards component of force I think. That's why the broken ends are at different heights. Perhaps a smallish force, but there seems to have been one. > > Surely if the centre of gravity over the rear wheels suddenly shifted this > would be enough to push the tyre, bear in mind that the suspension had > failed and the wheel was free to rotate in any direction, meaning that it is > entiely possible the the wheel was pushed two - three inches through the > pebbles in a horizontale direction. I saw an MGF's suspension collapse when > taking a corner at 100 ish mph, after wards you could see that the wheel was > at about 10 degrees from straight as there was nothing to hold it upright. > > Don't follow your point there. The wheel is attached to the body in a transverse axis by a couple of wishbones. It would be free to move front to back on an arc, but not in any other direction. Sent via Deja.com http://www.deja.com/ Before you buy.
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