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View Full Version : FLEX A FORM FIBERGLASS LEAF SPRINGS



trfourtune
03-22-2006, 02:34 PM
has anyone tried fiberglass leaf spings in their car? are these worth the money compared to steel? i see hyperco makes them also for the circle track guys. i am considering for my 1962 tr4.
rob

Matthew E. Herd
03-23-2006, 07:10 AM
I saw a pair in a former SCCA nationals MGB (which is now a sorry excuse for a car ... ). They're a heck of a lot lighter than the originals (I got to hold one too as the suspension was being dismantled). However, I'd imagine they're fearsomely expensive.

WhatsThatNoise
03-23-2006, 07:59 AM
Never knew they existed.....

I guess if they make helicopter blades out of the stuff, they probably have it kinda figured out by now.

aeronca65t
03-23-2006, 09:55 AM
I'm pretty sure that these have been around in Corvettes for a while (in the form of a transverse leaf in the rear)....did not know that they were avialable as an aftermarket item.
CORVETTE COMPOSITE SPRING (https://www.ecklers.com/product.asp?pf%5Fid=35265&dept%5Fid=1826)

trfourtune
03-23-2006, 10:39 AM
fyi, they charge $400 for a set. custom made to suit. not horribly expensive.
rob

Nunyas
03-23-2006, 01:43 PM
I've seen composite leaf spring sets for MGBs at a couple of locations on the 'net. I know it doesn't really help you and your application, but I *think* the pricing was roughly double standard leaf spring packs.

As another option to throw into the mix, I've seen an outfit in the UK (can't recall their name ATM) that makes elliptical steel springs (again for MGBs) that offer a weight savings over standard spring packs, slightly more expensive then standard springs but less expensive than composites.

Sorry, I don't have any info for your specific application, but I thought it might be a little helpful to toss in at least one alternative option...

trfourtune
03-23-2006, 03:21 PM
problem with steel mono leaf springs is that when and if they break it is catastrofic. that's why the search for composite.
rob

Nunyas
03-23-2006, 05:13 PM
ah! I did not know that... learn something new every day /ubbthreads/images/graemlins/smile.gif

thanks for the info

kennypinkerton
03-23-2006, 06:16 PM
Wouldn't a break from a composite spring be catastophic too?

I remember them being available for lowrider pickup trucks too - many moons ago when I would buy those magazines.

Matthew E. Herd
03-23-2006, 06:22 PM
Yes, the composite spring I saw was a single leaf ... the failure would be equally catastrophic! Not to mention, I'd wager fiberglass has a poorer fatigue resistance than spring steel (but I don't know this for a fact).

mjamgb
03-24-2006, 02:24 PM
Even multiple spring packs fail from time to time. Usually at the highest shear point... right at the mounting eye. Since the spring pack at this point is just one leaf... Don't see why a mono-leaf is any less safe. In any event, you still have the other spring and your shocks holding it together intul the ride comes to a stop.

trfourtune
03-24-2006, 03:31 PM
actually, the fatigue resistance of the composites is far greater than steel (assuming the composite is correctly designed and made). steel snaps straight accross when it goes. composites (of the right design) don't fail that way.
they partially break,sag,bend. they don't just snap. multi leafs may break one or two but the others still hold everything together.composites have come a long way in 20yrs.
i worked for the forrest service when i got out of high school (a long time ago) repairing 4X4's and we replaced a lot of broken springs. most springs broke in the stack (99%)and not near the eye.
the dirt oval guys are the pioneers of the racing composite mono leaf and they did it because of the constant breakages and to go faster. those tracks get pretty rough.
flex a form do not show a thicker section near the axle mount which i find questionable. hyperco and the ones for the mg guys do have this detail.
rob

Bugeye58
03-24-2006, 10:07 PM
A steel mono leaf failure is sudden and can be catastrophic, as the break is essentially instantaneous. When a composite spring fails, it is more of a "greenstick" type of fracture. Think of breaking a dry twig as opposed to a green one.
Jeff

aeronca65t
03-25-2006, 06:24 AM
My buddies 1/4 elliptic Spridget broke one of the main rear leaf springs in the middle of a high-speed turn at Pocono last year.
This is the car I occasionally drive in enduroes with him.

I was following him at the time.....what a "joy-ride" he took!
Yep, steel springs break *very* suddenly!

DrEntropy
03-25-2006, 08:31 AM
I've experienced exactly ONE leaf spring failure. MGB. Instantaneous, and a fair o'l bit o' pedal stabbin' and "driver input" went on with that. I'd MUCH rather have a gearbox or engine scatter than have a rear end go squirrelly unexpectedly. Adrenal gland was already workin' in deficit, that put it into a week's worth of catch-up. sheesh.

How is it they never break while sittin' onna trailer?!

WhatsThatNoise
03-25-2006, 12:36 PM
I was wondering about the panhard bar that is on my Pinto.

Seems it is a rather common mod. (Pinto has leaf springs)

I have had day-mares of going off the carousel at Nelson.
(Have you seen what is driver's left of the carousel) /ubbthreads/images/graemlins/eek.gif /ubbthreads/images/graemlins/angel.gif

DrEntropy
03-25-2006, 08:09 PM
heh...not "lately" but I suspect it ain't changed in the last twenty years. "Weeds" would be a kind description. Downhill too, IIRC.

Nunyas
03-26-2006, 12:04 AM
[ QUOTE ]
I was wondering about the panhard bar that is on my Pinto.

Seems it is a rather common mod. (Pinto has leaf springs)

I have had day-mares of going off the carousel at Nelson.
(Have you seen what is driver's left of the carousel) /ubbthreads/images/graemlins/eek.gif /ubbthreads/images/graemlins/angel.gif

[/ QUOTE ]

from what I gather it seems to be somewhat common to do on Spridgets, too.

WhatsThatNoise
03-26-2006, 03:02 AM
[ QUOTE ]
"Weeds" would be a kind description.

[/ QUOTE ]
Those "weeds" would be the tops of giant Cyprus trees growing out of a late Jurassic period swamp, hundreds of feet below track elevation. Supernatural creatures of heroic size quickly dispatch trespassers & play matchbox games with what is left of their vehicles.

Bugeye58
03-26-2006, 05:04 AM
There used to be neolithic cattle that romped around in that area. I've heard rumors that they are now extinct.
And, wonder of wonders, Nelson now has a real flush toilet.
Jeff

DrEntropy
03-26-2006, 12:17 PM
Just th' ONE tho, huh?

I remember the cattle being on the outside of the "back" straight... just before 13? The Carousel had some sort of barbaric fencing along its outside IIRC, and some odd "gaps" in it from prior "indescretions". Not a place to go off, certainly.

Bugeye58
03-26-2006, 12:27 PM
The last I knew, there was only the one. Still no showers, though, and I think you still need the flatboat in the paddock.
Jeff