Checking condition of rear springs on a Bugeye

[DanLewis]

I think the rear springs on my Bugeye are weak with age because the car bottoms out on fairly mild bumps in the road. Since the available aftermarket springs apparently raise the rear end unless you remove some of the leafs, I'm reluctant to replace the springs unless I can determine that they really are worn out.

I took some measurements, put them into Excel, and made the plot shown below. (Click on the thumbnail to get the full size image.) Each measurement was taken by having someone sit directly over the rear wheel and then measure the change in the distance from the garage floor to the top edge of the wheel arch. The data looks pretty linear, which is what I would expect, but I'm wondering if the slope is the same as a good spring or not.

Would any of you with Bugeye's be willing to take a similar measurement and let me know the amount of deflection?

Thanks!
Dan

 

[bug_sixty]

standard is the two finger test... fingers setting vertical on top of tire should fit below the wheel arch... Other factors that are a real possibility...first and for most shocks...they produce the bottom out effect and go south quickly.... the last which is the worst is the spring boxes are rusted out or partially so.... Don't get me wrong..... Spring do go bad but they are pretty stout if you look at them...

 

[Trevor Jessie]

Springs will lose arch over time and will also lose some "spring". Weak shocks may make the problem a bit worse, but I wouldn't expect a BIG difference. In my case the problem was obvious. The amount of rust on the springs had made them weak. I went ahead and sand blasted the leafs and put it back together and hoped for the best, but they were too far gone. I installed the rally spec springs by removing three leafs ad installing a wedge to lower the car. I really like the way the car handles and the rear axle lateral location is very firm despite the lack of a panhard bar.

 

[DanLewis]

standard is the two finger test... fingers setting vertical on top of tire should fit below the wheel arch... Other factors that are a real possibility...first and for most shocks...they produce the bottom out effect and go south quickly.... the last which is the worst is the spring boxes are rusted out or partially so.... Don't get me wrong..... Spring do go bad but they are pretty stout if you look at them...

Springs will lose arch over time and will also lose some "spring". Weak shocks may make the problem a bit worse, but I wouldn't expect a BIG difference. In my case the problem was obvious. The amount of rust on the springs had made them weak. I went ahead and sand blasted the leafs and put it back together and hoped for the best, but they were too far gone. I installed the rally spec springs by removing three leafs ad installing a wedge to lower the car. I really like the way the car handles and the rear axle lateral location is very firm despite the lack of a panhard bar.

I've had the springs out to clean them and the spring boxes. There was almost no rust at all, so I think we can rule that out. The shocks were replaced a couple of years ago, but of course they still could have gone bad. I'm hoping that's the case, because there's a good fix for that and I really don't want the aftermarket springs if I don't need them.

I'll try the "two fingers" test, but it sounds like it might not be that accurate. 'Sure would appreciate anyone who is willing to take the deflection measurement described in my original post and let me know how yours compare.

Dan

 

[Trevor Jessie]

Did you disassemble the spring pack?

 

[DanLewis]

Hi Trevor,

Did you disassemble the spring pack?

Yes. I wanted to get all the dirt and grime out from between the leafs to eliminate the squeaking I was getting. If you're wondering whether one of the leafs is broken, all I can say is that they were all good when I took them apart, and that was only about five or six months ago.

Dan

 

[Bayless]

I'm with bug_sixty on this one. Springs can weaken over time but the main result is the car sits lower at rest which also reduces the available spring travel over bumps. Shocks are the main thing that prevents bottoming or excessive spring travel. When you replaced the shocks did you have Peter C rebuild them or just get a pair of used ones?

 

[DanLewis]

I'm with bug_sixty on this one. Springs can weaken over time but the main result is the car sits lower at rest which also reduces the available spring travel over bumps. Shocks are the main thing that prevents bottoming or excessive spring travel. When you replaced the shocks did you have Peter C rebuild them or just get a pair of used ones?

The shocks were replaced with new (or possibly rebuilt) ones by the previous owner, but I don't think he got them from Peter. I've tried the "bounce" test to see if they've failed, and they seem OK. However, I've thought of removing them to be able to test them more easily, but checking spring deflection seemed the easier thing to do first.

Dan

 

[DanLewis]

standard is the two finger test... fingers setting vertical on top of tire should fit below the wheel arch... Other factors that are a real possibility...first and for most shocks...they produce the bottom out effect and go south quickly.... the last which is the worst is the spring boxes are rusted out or partially so.... Don't get me wrong..... Spring do go bad but they are pretty stout if you look at them...

I just tried the "two finger test". I could fit three (of my) fingers between the top of the tire and the top edge of the wheel arch. Actual distance was 2 and 3/8". What bothers me about this method is (1) my fingers are probably smaller than yours, (2) there was no mention of how full the gas tank should be (mine is about 3/4 full when I measured), and (3) there was no mention of tire or wheel size (I'm running 175/70x13's).

Dan

 

[JPSmit]

How much do you weigh?

 

[DanLewis]

How much do you weigh?

I'm the one with the data point at 170 pounds on the graph. :eagerness:

Dan

 

[bug_sixty]

This is all to personal for me Dan...haha The bounce test doesn't work on BE's! 1/4's are to .... stiff. Here's the deal... you already said the springs look fine.. the two finger deal is good and the spring box is solid...right... The shocks are the ???? so not saying their bad...but to be sure they need your close attention...Peter C rebuild is the one cause he's the ONLY one that' s got it right...the shocks don't leak coming out of that address... opps!! this should be sent to the vendors page...sorry guys

 

[bug_sixty]

Oh, don't think BE's don't hit the rubber limiter occasionally, any big depression...they will and do more so with passenger and (the very personal) weight is concerned... gas tank... not so much cause the .... tank can only hold 7 gal.

 

[bug_sixty]

Personally I've tried the shock conversion deal...TWO of them... and was always disappointed...(if you want to try, I still have them and will sell them at auction price) If you want to put the engineering to this deal, lets figure out why those OEM shocks work so well....

 

[AN5Sprite]

I don't know what to say Dan.... I just accept that they always bottom out pretty easily. There's just not much travel there. I've been reading a lot of Peter Egan lately. He frequently mentions the "coal cart" suspension of British sports cars. (as an endearing trait, not a criticism)

Would a more practical measurement be from the bump-stop platform on the axle to the platform on the arch directly above that point? (Take tire size and bump rubber wear out of the equation)

My question, in case the Moss rep is reading this: Why can't Moss provide a proper replacement spring? If you're going to offer a spring that has only one application, shouldn't that spring resemble (in form and function) the piece it's intended to replace? What the heck happened there?

 

[DanLewis]

Personally I've tried the shock conversion deal...TWO of them... and was always disappointed...(if you want to try, I still have them and will sell them at auction price) If you want to put the engineering to this deal, lets figure out why those OEM shocks work so well....

Thanks, but if I do have to replace the shocks, I think I'll go with Peter C's rebuilds. They seem to have a great reputation around here.

Dan

 

[DanLewis]

Oh, don't think BE's don't hit the rubber limiter occasionally, any big depression...they will and do more so with passenger and (the very personal) weight is concerned... gas tank... not so much cause the .... tank can only hold 7 gal.

Interesting. I have a local friend who owns four (yes, really - four) Bugeyes, and he claims that if the springs and shocks are good that he never bottoms out. Maybe a little bit of exaggeration, but far from happening all the time like mine - and with only me in it, too!

Dan

 

[DanLewis]

Would a more practical measurement be from the bump-stop platform on the axle to the platform on the arch directly above that point? (Take tire size and bump rubber wear out of the equation)

That would certainly be a better way to see if the springs are sagging with age.

My question, in case the Moss rep is reading this: Why can't Moss provide a proper replacement spring? If you're going to offer a spring that has only one application, shouldn't that spring resemble (in form and function) the piece it's intended to replace? What the heck happened there?

Hear, hear!

Dan