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MG Midget and Sprite Technical - Frogeye ride height

Now my Frogeye is on its wheels it is clearly sitting too high at the back. This is partly to do with being on its temporary 14" wheels and 80 profile tyres which probably adds about 1.1/4" to the ride height. The top of the rear wheel arch flange is at 27.1/8", (same both sides !!) so if it were on standard wheels this will come down to about 25.3/4". Still too high I think.

There isn't much more to fit to the car at the rear that weighs much other than some fuel. It will no doubt settle a bit once its in use, but I suspect I will need to add some "wedges". Approximately what "target" height would be standard for a Frog?
GuyW

Ideally, you need to measure from the centre of the wheel/halfshaft to the wheelarch.

That way you can compare ride height with other Frogeyes, no matter what size wheels and tyres are fitted.
Dave O'Neill 2

Ahh! Dave, of course! Why didn't I think of that. :-)

16" exactly. Seems high. Who makes the wedges? - suspect its Ashley Hinton or someone like that rather than Moose.
GuyW

Guy, I've forgotten - did you use the original quarter elliptics or later ones as the latter give a higher ride height I believe.
Bill Bretherton

I don't know Bill. How do you tell them apart?
Mine came with the car - they have 15 leaves, does that help?

Whichever they are I still need an idea of a reasonable looking height as a target to set the car to.
GuyW

15 leaves is the correct original spring.
David Billington

Peter May used to supply wedges.
Dave O'Neill 2

I think it should look like this, Guy. Cherry's did. No dims, though. But Bob Beaumont's frog is on the road - he'll be along soon.

Nick and Cherry Scoop

I just measured my original spring, stock height 59 Frog and from the center of the axle to the top of the arch it is 14 inches on both sides. HTH
Martin

Thanks Nick, I had forgotten about that diagram!
Since I don't have a screen fitted the only vertical measure is J. This is labelled as 5" minimum ground clearance so not the sill height but the lowest point on the car which would be the exhaust wouldn't it? The sill would be about 6.1/2" by that logic. My sill currently measures 9", so take off the excess due to the oversized wheels that will be 7.3/4" That's 1.1/4" too high though it may settle a bit yet.

I think I still need that wheel centre to wheel arch lip height.
GuyW

Thanks Martin,
Mine is definatly too high as I suspected. Somewhere between 1" and 2" but too many estimates in there at the moment to act on that just yet. But its good to know it should be possible to adjust it sufficiently with wedges.

Since I have rebuilt this body shell completely - everything other than the transmission tunnel - its pleasing to know that it sits perfectly level even if it is a bit on the high side.
GuyW

As we all know, these cars are not clones of each other. My ride height may be the same on both sides but the axle itself is not perfectly centered. Its over to the left a bit. Yours will probably settle some once you get it back on the road and then you can see how much to lower it.
Martin

I'll have a measure at the weekend. I have the standard 15 leaves. I recall mine was a bit high at the rear when it was rebuilt but it has settled down over the last couple of years
Bob Beaumont

With a fresh build it's usually necessary to settle the rear springs to see the real ride height. What I usually do is stand on the rear bumpers and vigorously bounce the rear end for a minute or two. This also flags up any clonks or squeaks as the suspension is deflected. Wedges will cost around 60 quid - but it's easy enough to make you own. Using wedges you can also trim left to right ride height, should there be any variation. On my car I've also taken out a couple of leaves from each side which has increased compliance and improved the ride quite a bit.
f pollock

At least, being high, it can only settle down towards the "correct" height. 1" to 2" doesn't sound a lot to me. You wouldn't want it to start low presumably.
Bill Bretherton

Peter May do still supply 1/4 ecliptic lowering wedges: https://www.petermayengineering.com/product-category/rear-suspension/

Cheers
Mike
M Wood

This thread was discussed between 01/02/2018 and 02/02/2018

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