Stock Spring Rates?

ecohen2

True Classic
Hey,

Does anyone happen to know what the stock spring rates were for Bertones? Front and back?

Thanks,
Ed
 
From what I have been able to determine, stock spring rates seem to be - well at least for the early 80's North American spec X1/9s - about 120-125 lb/in front, and about 150-155 lb/in rear. I cant say for sure that the later Bertone models were the same, but I believe they are.
 
Ideally, someone with a spring tester could do this. My local race shop had one, but I never tested the original springs.
 
From what I have been able to determine, stock spring rates seem to be - well at least for the early 80's North American spec X1/9s - about 120-125 lb/in front, and about 150-155 lb/in rear. I cant say for sure that the later Bertone models were the same, but I believe they are.

I seem to remember this being about right. I know the springs are very soft. I am wondering why you want to know the stock rates?

You can calculate the rates if you have good measurements of the springs. Remember that a coil spring is nothing more than a torsion bar twisted into a spiral.

https://www.thespringstore.com/spring-rate-calculator.html
 
I was looking at new springs on a couple of different sites. They all indicate how many lbs front and rear but without knowing what the stock were I had no frame of reference...
 
Ed, I understand your concern. Back in the day, "sport springs" for most import models were about 20 to 30 percent stiffer than stock and usually about 1 to 1-1/2 inch drop. That would come to around 150 pound fronts and 180 pound rears for the X. Now I see some aftermarket springs in the 400 to 500 pound ranges (and up). In my opinion that is incredibly hard for street use on such a light car, and even toward the hard side for track use in most cases. Depends on your intended use and the set up for every other component of your suspension/chassis.

One of my X's came to me with 225 front, 275 rear springs and it is very rough and uncomfortable on even decent streets. The other X has 'sport springs' that are under 200 pounds (don't recall the exact numbers, but I think they are 160/180), and they work very well for my street use. Both have dampening that match the spring rates and otherwise stock suspensions. Perhaps this offers a little comparison. But I'm sure others will say differently very soon here...
 
The whole reason Xs seemed so nice to me in the handling department is they handled great but had nice compliant springs, unlike the spider which seemed to use chassis flex as a major suspension component. I don't know about you guys but the DC area has terrible roads and any car with super stiff springs is going to beat you up. Instead of making the DC area Xs more like roadracers we should be jacking them up on tall soft springs to look like rally cars......some 165 series lugged tires, rally mud flaps and half a dozen driving lights would finish off the effect nicely.
 
The whole reason Xs seemed so nice to me in the handling department is they handled great but had nice compliant springs, unlike the spider which seemed to use chassis flex as a major suspension component. I don't know about you guys but the DC area has terrible roads and any car with super stiff springs is going to beat you up. Instead of making the DC area Xs more like roadracers we should be jacking them up on tall soft springs to look like rally cars......some 165 series lugged tires, rally mud flaps and half a dozen driving lights would finish off the effect nicely.

Somebody was going to post it, might as well be me. :)
normal_X14x4.JPG
 
You had to, didn't you Jim?
I was hoping the next thing I saw was a picture of a really cool rally car.
2013-volkswagen-polo-r-wrc-race-car_100412600_m.jpg


Instead you went and did that. Thanks a lot. :mad:
Why won't that picture ever just go away...
 
The whole reason Xs seemed so nice to me in the handling department is they handled great but had nice compliant springs
That pretty much echos what I was saying about spring rates.
I've had street cars with everything from track level rock-hard suspensions to sloppy-soft air bags. Now I must be getting older because I am over the rough uncomfortable ride. Not that I'm against the options, just rather keep them where they belong; stiff springs are for a track only car, air bags are for a show only car, and a good compliant spring rate is for a street car. I suppose if you only own one car you might be tempted to lean one direction or the other depending on your preference. But if you only had one car hopefully it would be something other than a X.
 
I agree with Carl that the OEM springs delivered a reasonably comfortable ride for a small sporty vehicle although I never cared for the body roll of the stock suspension (funny, but my younger kids would sometimes say they were afraid the X would roll over in a hard turn :p). Ride & handling are of course very personal, but I ended up finding some progressive springs which (for me) resulted in a comfortable ride overall but greater firmness under spirited driving. I also added a front anti sway bar which I understand introduces some understeer but reduces body roll. Mine is a pampered street vehicle that I press a bit when able to carve the asphalt back-road twisties of New England and it suits me well.
 
Good ride quality is a lot more than just soft spring rates. If you compare modern sports cars to their predecessors of the 70s and 80s you will see a marked improvement in ride quality and roll reduction, seemingly competing interests.

By modern standards, I find the stock springs and shocks on the X1/9 to produce an unsettling amount of roll. The impression is sloppy and un-checked. With a good set of shocks and proper spring and swaybar rates a very good compromise can be reached. The biggest problem we have is sourcing the shocks. With limited options one is forced to build something custom.
 
I ended up finding some progressive springs which (for me) resulted in a comfortable ride overall but greater firmness under spirited driving.
Do you know what the spring rates are on them? It could be a good point of reference for Ed's goal of this thread.
 
If you compare modern sports cars to their predecessors of the 70s and 80s you will see a marked improvement in ride quality and roll reduction
But of course our point here (in this thread) is not to compare the X with other vehicles, but to compare the stock X's spring rates with optional ones. In other words, all other variables remain the same. As Ed stated....
I was looking at new springs on a couple of different sites. They all indicate how many lbs front and rear but without knowing what the stock were I had no frame of reference...

But I agree with your point, and especially about the shocks (even though that wasn't Ed's question). It is difficult with no real shock options specific to the X available any more.
 
A couple of photos for reference. Body roll is a function of lateral g, spring & bar rates and geometry. My old DSP autocross car could generate nearly 1.5 lateral g. At its zenith it had either 750 lbs/in or 800 lbs/in front springs. People used to tell me that couldn't possibly work. In response I would often show them this photo, trail-braking into a corner on a very grippy surface could produce an amazing amount of weight transfer.

TP-MidAtlantic.JPG


Then there is is photo. Again at maximum lateral g (probably approaching 1.5g). Lifting the inside front tire is as much a function of roll axis inclination as it is weight transfer.

NorthSlalom3b.JPG


While you wouldn't want to drive this car long distances on the highway, given its 3Hz ride frequency, it actually rode the bumps on the racing surface very well.
 
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