Can anyone help me? I built my own frame and put a new 4" drop Superbell axle set up with spring over from Speedway Motors. The car drives straight as an arrow and turns good. The problem is that at 2,800 rpms the front tire's hop. After I push through 3,100 rpms it goes away. So on the freeway I have to drive 60 mph or 80+ mph. My front shocks are layed over at a pretty good angle, but would this cause the wheels to hop? I have the caster set at 7 degrees and toe in at 1/16". Should be fine for bias ply tires. I even had the tires re balanced and rotated with the back. Everything is tight. What could it be?
How old are the tires ? Did you check to see if they are round ? Are the wheels straight ? Have you tested it with radials ?
Go to a shop that has a road force balancer .State of the art tire and wheel balancer http://www.gsp9700.com/pub/images/demo.cfm
The problem is speed related, not rpm. Could be something out of balance in the brakes. But I would suspect the tires. Belt separation can show up as a vibration.
What kind of car and what type brake setup? On some T Buckets that use a heavy disc brake setup, people have complained of this problem. The problem seems to be that the rotors are not balanced. You won't notice it on a heavy car, but it shows up on light weight cars like T Buckets. It has something to do with "unsprung weight". It seems the cure is to have the tire/wheel/rotor balanced as a complete unit. Some say there are places that do this. On a side note, for some reason, not all t bucket owners running a heavy disc brake setup have the problem. Or maybe they do and just live with it.
what shocks.....and yes it will do what your talking about....been there , done that , changed those...and it went away
Along with the square tire problem, I've also seen issues with buick drum conversions causing issues (balancing).
or an improperly mounted tire, easy to do with bias ply tires and old rims. have someone drive next to you and look at what's happening...
you need what is called "on the car spin balanceing",same thing as above,just different name. strobe light balanceing and trueing.triming away the tire until its perfectly round.
The Raven had that problem with his '27. His drums were out of balance, he cured it by haveing the wheels balanced on the car, been shops around that do that as long as I can remember. Lotsa folks have out of balance brakes and as has beem mentioned its not as big an issue on a heavy car as it is on a light one.
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