Stiffer springs

**Stroprock** · 04-01-2013 19:29

The rear single leaf springs on my car are from a Reliant kitten, but with the Rover v8 power, heavy steel a35 body and MGB GT rear axle, they are just too soft and wallowy, even with adjustable dampers. So after a bit of research I found that instead of single leaf springs, the Reliant Fox van had some stiffer multi-leaf two stage type springs on the rear to carry a heavier load.
I have bought a pair in the hope these will stop the rubbing of arches on corners and leaning when the driver sits in!! Now I haven't fitted them yet, but they feel about the same as the Kitten ones I have just taken off (simply judged by standing on them both and comparing the two that is). Since they are progressive, so are stiffer the more load they are under, should these still be stiffer once I have the fitted and under load? I don't want to fit them if they are not going to be any help whatsoever.

Top are new fox springs, bottom old single leaf kitten ones

**russ6120** · 04-01-2013 19:39

I'd have thought the van springs would be stiffer when they are fixed together

**chevy2** · 04-01-2013 19:39

Unless you can add something heavy like a gearbox? or similar on each spring and measure how much each one compresses to compare you'll problem have to fit the new ones on the car to compare,
Bear in mind when fitting another set of springs new or used they never seem to settle to their ride height straight away?

**Stroprock** · 04-01-2013 19:53

OK, just feels the same as the others off the car, but I'll have to see when i fit them

**20vT_pop** · 05-01-2013 20:33

Coil over shocks probably be the best bet, then you can tweak the spring rates to suit what you need, and you will still be using the leafs to locate the axle.

John

**fozwanger** · 05-01-2013 21:04

They will feel the same with a light weight (such as yourself) on them. In essence you aren't putting any real load on the springs. If you looked at spring rates on a graph it would be easier to explain. The springs are at their softest when they are under no load (unless you take them through the elastic / plastic boundary) and you will get the same amount of deflection until the spring rates really come into effect (Higher loads - weight of a car for instance)

**Stroprock** · 05-01-2013 21:10

I haven't got coil over shocks, but the adjustable Gaz tube shocks fitted atm allow me to tweak it. I think they are 40 clicks from lowest to highest. The trouble is if I set them at say 5 up from the lowest setting, so fairly soft, it leans when you sit in it (an even when you don't after while!!) and the rear wheel rubs the arches on corners. Yet I wind them up a few clicks and it doesn't lean, but instead its as solid as a rock as if I have no suspension at all!!!
I was told on here that I needed leaf springs with higher spring rates and that the adjustable dampers won't actually get to the root of the problem, hence me landing these Reliant commercial van leaf springs.

**mygasser** · 05-01-2013 22:20

if you fit them and its still not stiff enough the cut the eyes off the kitten springs and add them between the 1st and 2nd leaves of the fox springs.

AustinofEngland · 30-05-2014 17:33

My three Kitten saloons all had the type you refer to as commercial. This is backed up by my Haynes manual. The last springs I bought had five leaves, all of differing length.
I have never seen single leaf springs before.