I found an explanation that some guy posted on the Vortex forum but it's complex to say the least..

Wikipedia doesn't offer much either..

Visually there does appear to be more negative camber on heavily lowered cars, but that might not be true to fact..

The only thing I can think of is.. if the top and bottom mountings of the coilover aren't vertically inline, then lowering the car and thus making the coilover shorter, should create negative camber.. because the wheel would be brought closer to the chassis but the centre of the twist beam would stay the same distance.. effectively bending the beam in a slight 'U' shape.

However if the suspension was perfectly aligned then the whole beam (if it were a 'H' shape for example) would just pivot.. the beam would remain completely straight.. eg. if you brought the wheels 1" closer to the chassis, then the centre of the beam would be brought 1" closer to the chassis.. but that doesn't seem too likely IMO....

I dunno I'm just thinking out loud, I've never physically tried any of this, all I know is when I lowered my car by a large amount, there was visibly more neg. camber...

Surely the coilover will shorten and twist before the beam "bends".

I can't see how this is anything more than an optical illusion.

From stanceiseverything.com:

"Most cars come with some degree of negative camber from the factory as it is beneficial to handling. Lowering a vehicle in most cases (straight axle applications are exempt) increases the negative camber. These increases are to be expected and are positive to up to a point.

Read more: http://www.stanceiseverything.com/tag/lowe...14R4KPARO"

I dunno man, I can't get my head round it.. it can't just be an optical illusion, surely..?

It might be, especially if you combined the lowering with wider lower ET wheels and stretch rubber.

It's because they run a very slight toe out as far as I'm aware so when you lower the car, the beam moves in an arc as there is about 50cm between mounting point and centre of the wheel, this becomes negative camber the lower you go. My Mk2 16v looks like it's rocking quite a bit of camber at the back and it's not even all that low.

i think its just an optical illusion thinking you have more when you lower a car with a beam. because your wheel is next to the arch so you can spot the negative camber more. my 2cents