Technical Quarter elliptical Wheel hop.

I have a 3o for roadster, I have a quarter elliptical front end and am petrified to take it over 45MPH. I can feel and see the wheels hopping up and down. Currently I don't have any shocks-I have a brand new set of Shocks from a Harley I was thinking about using to try to help with this issue. I have a similar setup to the below picture although it's not actually of my car. My Shackles are just a little bit longer than the ones used in the image. Thanks.

 

Why bother posting a picture that is not of your car ?
Are you ashamed to actually post your own car for reference ?
As far as using motorcycle shocks, the answer to that one is don't bother. They are not built for the weight and won't have proper dampening.
The bouncing is not surprising with no shocks.
You need a proper shock made for the purpose and mounts that will support them.
Shorty tube shocks and F1 style mounts from So-Cal speed shop come to mind.

 

Harley coil overs ( which is what they are) are going to be over kill. Spend 20 bucks on a pair of Monroe tube shocks and cure the *****.

I'm with @Blue One why post someone else's setup when it is yours that has the problem.

 

It's quite possible that his own setup is a poorly built rat rod style build with more problems than just no shocks.
However I could be way off base.

 

Put some P&J shocks on.

I don't wear a belt, and my pants keep falling down. What should I do?
I can't find my gl***es, and I can't see. What should I do?
I hit my finger with a hammer. Why does it hurt?
I didn't study for my test. Why didn't I p***

 

I'm with the first two here, why are you driving a car with no shocks? Secondly, springs hold the car up, they don't do anything else and aren't responsible for wheel hop, out of balance wheels are to blame for that. Put some decent shocks on it, balance the wheels and send us pics of you grinning at the wheel.

 

I knew a guy once he looked just like me only different. But I think if I put on some Converse my feet would feel different.

 

Agree with above. your wheel hop is not, or likely is not, related to the fact you have 1/4 elliptic springs. It is more likely wheel balance and/or out of round tire and/or wheel alignment issues contributing to the basic problem of no shock absorbers. Start with shocks and wheel balance as recommended in above posts and go from there.

Ray

 

Snide comments notwithstanding, they are right, you need to add some good shock absorbers to the mix and make sure the wheels/tires are not out-of-round and are balanced. It would help to see a picture of the actual set up you have but there's nothing inherently wrong with a well executed quarter elliptic sprung front end.

 

Heres two pics of how I set up mine.Never ever a issue.Even at highway speed and bumps. Houdy shocks were nos. You have to have shocks!!!!! Hope this helps Jim

 

This may help explain why you're getting wheel hop without shocks to dampen it.

 

I agree , most process the spring as more than just support for the load . All the pieces play a role in correct suspension . Out of round / balance is one of the most overlooked issues . Shocks will dampen the movements caused by road surface , out of balance tires , etc. Just a little to thing about , if the manufacture of a car didn't need shocks in suspension design , how much greater would the profit margin be in the end . In our world every nut in manufacturing has a value if not necessary don't spend the money .

 

If I had any eggs, I would have some Bacon and Eggs, If I had some bacon.

 

Rough Crowd!

 

Yeah, but a fun crowd as well!!

 

Shocking..Never damped..

 

put some shocks on it, you will be "shocked" at the difference it makes.....

 

I like the way you've attached your shackle to the I beam allowing the spring to remain flat while traveling up and down. I think this keeps the leaf spring from twisting as it goes up and down and and not change the caster.

 

I don't run front shocks on my t-bucket, it only goes into bounce on p***enger side only at 72 mph. There's got to be something else going on with it to bounce so bad at low speeds.

 

Okay. I posted somebody else's car because I am not near my car. My car is not a Rat rod, It is a work in progress. But yes, I have driven it to try to iron out the issues. Why paint and polish a car that won't drive well? Rat rods are kitschy and while I like them,and get the rebellion thing in them. I also like polishing my work it feels good to spend the extra time and show off what I can do. That said, this is why I am looking at shocks and actually improving the cars ride. The Harley shocks are brand new, and were given to me. I also like the look of the Chrome coil over especially since my ch***is is otherwise all black. I was trying to devise a Cantilever style suspension with them-so they should not be over kill and will have a little mechanical advantage/leverage on their side. I ask asked for help because I needed it in doing this-I have never done a setup like that before. I didn't really expect to be persecuted for asking. The picture I found is actually from this website,I don't see any shocks in this picture either. I've seen tons of guys run 1/4 elliptical online sans shock-but have never heard about ride quality.

The wheel are balanced, I just took them off of my Chevelle and mounted them on here. The rubber is also fresh and the car tracks pin straight.

The fact that other guys run no shocks and don't have this issue intrigues me,I'm not trying to be lazy but I like the simpler no spring look if I can help it.

 

***uming your wheels/tires are balanced, you could still have a balance problem if the drum or rotor were out of balance. Normally they are balanced when manufactured, but can throw weights or they may have been removed for appearance's sake. A tire/wheel combo, including the drum, that IS balanced, should not start shaking at speed. Your might also check the wheel bearing adjustment, king pins for wear, etc.

Ray

 

You might want to try a site where people are more interested in helping rather than bashing.

 

All of the front end parts are new, king pins, bearings, brand new disc brake setup.

 

I'm not sure when the first bounce dampening devices were used but there been used ever since.

You go for ride in a car with no shocks, these that claim there's no problem, and decide for yourself if there's no problem and meets your expectations. Working Springs need dampening, plain and simple. Springs that don't work -are too stiff, wrong rate, wrong length, mounted wrong well,,, probably don't need any dampening because they aren't working.

It's really hard to give blanket approval as "good" to Chinese parts delivered by the cheapest bidder just because they are fresh out of the box. Everything needs to be checked.

 

An undamped spring especially on a light car like what your working on needs to be dampened. Depending on road conditions it can get dangerous fast. Even a friction shock is better than nothing. But a good tube shock is really all you need. I drove my a roadster home after a shock came off on the p*** side and every time I hit a semi non smooth section of road, the p*** side wheel would bounce to the point I did not feel safe driving as fast as I normally would on that road home. I know people run with out shocks on the front, I've seen it too. But people smoke crack and that doesn't normally work out to well either. Set up some shocks and go for a test drive. I think you will be surprised how much better it is.

 

Jeez, this "bashing" is about 1/10th of the old HAMB. Does that make it wrong or mean? You asked a question, you got good answers and a little ribbing. Sounds like a typical exchange between old car people. I'm not sorry if you don't like it.
"box the frame, Blue Bear. And put some shocks on it too!"

 

Well shocks are needed on all four corners not only to have it ride and handle decently but the motor vehicle code of every state I have checked requires it.
I'm not convinced that the Harley shocks no matter how pretty they are are what you want on it though. You would at least have to take the springs off.
As a couple of others mentioned wheel (and hub and drum/rotor) balance will cause the vibration you are experiencing as will an out of round tire or a tire with a tread separation.
First thing I'd do is jack the front wheels off the ground and spin them and watch to see if they show out of round or any lumps.
Then I'd find a shop that can spin balance the tires on the car. Just spinning the tires up with the motor part of the balancer and see how much vibration you have.

 

You must have shocks.

The Harley shocks are totally incorrect for this application.

The weight, the rate, and the geometry are all wrong.

 

Tire pressure to hight for light front end ,
Shocks to stiff , wrong location for the spring you are using,
If you do not wante to run shocks , it is possible !!! But MATH is required ,

Two H-D Soft Tail shock might work ,
Soft tail wight is around 700 pds ,
I think ,

 

That is the fast-track to a bad accident.

Insurance companies do investigate accidents. If it is found that you do not have shock absorbers on all 4-corners, your insurance policy will be voided on the spot, and you will be held fully liable for all damages, if you survived.

Shock absorbers dampen excess kinetic energy in the suspension, converting it, via friction (by a variety of means) into heat, which is dissipated into the atmosphere.

Without them, you can experience severe and instantaneous unrecoverable loss of control of the vehicle.

Trust me, I am an engineer.