Thread: Parabolic leaf springs

Our shorty with parabolics on it rides even better when loaded with a 150 or so kg.

Cheers, Mick.

Originally Posted by chazza

It is a pity that Isuzurover's photographs of his car with modified standard springs, are no longer visible in his post on page 2 of this thread, because they showed the incredibly good axle articulation that he achieved - possibly as good as parabolic springs.

I mention this for three reasons:
1. The quality of the steel in the Rover springs is very good and Ben did not break any of the original ones.
2. I know of two people who bought parabolics and had two breakages fairly early on. This is probably a result of poor metallurgy, or bad heat treatment. A search on the net finds many anecdotes about breakages.
3. Parabolics are rather expensive and the Rover ones are very cheap.

Cheers Charlie

Agree with most of this and if you're just buying second hand original springs then yes, quite cheap. Finding good ones is becoming harder and buying new standard springs is almost as expensive as buying parabolics.

I suppose it comes down to personal tastes, what you want and what your wallet looks like I suppose. I don't think there's anything wrong with a set of standard springs in good condition, I've just found the ride from parabolics to be better and it suits my project as I'm doing plenty if other stuff to the vehicle to make it suit my needs better.

I have just replaced my multileaf rears on my current project 88".
I had reset each leaf and greased them before fitting. Its a heavy duty pack as well.
It sat fine when I first installed them but as not registered yet I did a few laps around the horse paddock now after afew months it was sitting decidedly low. The front is higher than the back.
So I bought a set of Britpart rears. (all I could get in Brisbane).
The pack I removed, when a straight edge is centred in the two spring eyes, measures 220 mm from the line to the top of the spring pack.
The new parabolics measure 210 mm.
Now fitted it sits up back where I want it. How much they will sag I dont know. I have kept the same shocks on as they are new and have enough travel.
It will be a week or so before I can report on the ride.
The photos show the old pack and the rear with the multileaf on the rhs and the parabolic on the lhs.

Keith

Your old set are 'station wagon' springs rather than heavy duty! That is, the main pack is light duty for a comfortable ride, with the very heavy secondary leaves at the bottom to carry heavy loads.

I will stick will original, lubed between leaves, on Gilbert.
wont seem so bad if I ride my 77 Honda, Or 1960 Greeves.

whitehillbilly

Originally Posted by 67hardtop

Has anyone checked out Heystee parabolic springs?? Hes got lots of nice land rover mod stuff...

Cheers Rod

sorry i dont know how to put links in

Yes, I have Heystee parabolics on a S3 109" and their power steering as well, both have been excellent the last 3 to 4 years, completely fault free!

The steel of the Heystee parabolics compared to the Britpart ones is more pliable, you get a softer ride and more articulation, I had 2 Britpart parabolic leaves break before I changed to Heystee.

Parabolic springs have thicker leaves than conventional springs. From simple geometry, this means that the strain, or stretching, on the upper surface of the leaf is greater than on the conventional leaves for the same spring deflection.

This makes the metallurgy and surface finish of the leaf more critical, as it becomes easier for any imperfection to start a crack due to the formation of a stress concentration. And makes the springs more vulnerable to stone damage. And the fewer number of leaves makes a breakage more likely to disable the vehicle.

I was thinking of going Parabolics on mine just after I bought it, but I relly don't find it too bad.

My rear springs are a bit different from standard springs though. Not sure what brand they are.

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