Having read a few posts on the whole live axle / de dion / irs topic i have a query. Has anybody managed to actually get weights of components to be able to quantitatively compare them. How much heavier/lighter is dedion compared to live axle etc?
(should i have put this in the GTS De dion forum? maybe i will as well)
Cheers chaps.

The de Dion tube weighs next to nothing, it should be thin wall tube similar to that used on a prop shaft.

When discussing the advantages of full IRS against de Dion unsprung weight isn't the issue many people think it is. The only disadvantage of de Dion is the disturbing effect of a single wheel bump on the opposite wheel but it has the advantage of better camber control. particularly under hard acceleration and braking..On a billard smooth surface almost any de Dion is as good as the best irs but on a roughish surface even a half decent IRS is better.

The big advantage of de Dion over a live axle is not only is the axle lighter but any mass is concentrated at the ends not i a heavy diff in the middle of the axle, I won't go into the reasons for this but it means the axle gives better contact with the road and better ride quality than a live axle car.

In a Locost with a live axle the easiest way to reduce unsprung weight is to use the MK1 Escort style English axle -- the axle casing is made from thind steel weighs a heck of a less than the Atlas Salsbury style particularly the a 2 litre Cortina versoin.