Axle weights for anyone interested

**sifty** · 25-08-2012, 08:48 AM

I'll put this info here because it took a while to work out and my well be of use to someone else someday.

A while ago when I was researching new suspension options I settled on the H&R Cup package of matched springs and shocks. This lead to a new problem:

Basically you can get the kit with any combination of the following:
Fronts rated for up to 660kg
Fronts rated for 661kg and over
Rears rated for up to 570kg
Rears rated for 571kg and over.

I asked around various suppliers and forums for advice on how to choose the right spring weight. What I got was either no answer or answers that were clearly wrong. Also I found it very difficult to find actual information on the axle weights of various Mk1s. There is a weight plate under the bonnet, but the wording was a bit ambiguous.

As luck would have it a friend of mine came to stay with this German wife, who gave an accurate translation of the plate under the bonnet.

The first figure "Gross Vehicle Weight" is actually the Heaviest the vehicle may weigh fully loaded. - 1310kg
The second figure "Gross Combined Weight" is the maximum combined weight of the car and a trailer - 2510kg
Front and Rear axle weights are the most load you're allowed on either axle (provided the total doesn't equal more than the "Gross Vehicle Weight".

Of course this is not a whole lot of use without knowing the empty weight of the car!!!
Ok. So we got carried away and weighed them both at each corner and we added weight (me) to the front and rear seats and recalculated the weights to work out the percentage split that the weight adds to the front and rear, then I made a spread sheet so I could plug in different weights to see how the balance would be affected.... Yes, I get carried away sometimes...

All weights are in KG, both cars had nearly full tanks of gas onboard - 35L each (weighing 25kg)
My Hardtop is an 1800 and the Cabby is a 1600, also the Cabby has a towbar we'd estimate at another 20kg.

Front Rear Total
Hardtop: 562 327 889
Cabby: 591 393 984

The weight % splits are useful, if you want to work out what spring weight you need. So if you add eg: a 80kg driver, how much of that weight goes to each axle. etc.

Weight added to Front Seats:
51.63% adds to the Front Axle weight 48.37% adds to the Rear axle weight.

Weight added to the Rear Seats:
17.65% adds to the Front Axle weight 82.35% adds to the Rear axle weight.

Back to the original question then: Which H&R springs to choose?

For my purposes, I'm generally going to weigh under 660kg front axle and most people would weigh under 570kg rear too.
Here is an example: if I had 2 x 80kg people in the front and 1 x 80kg in the back and a full tank of gas (which is honestly the most load I'm likely to carry. Then my front axle weight would be 659kg and my rear 470kg.

There you go.

If you want to get really carried away, I also have the individual corner weights:

Hardtop Cabby
LF 286 293
RF 276 296
LR 159 188
RR 168 193

As you can see, the Cabby carries most of it's extra weight out the back.