ok i got new rims and tires about 2 weeks ago and i am starting to feel between the 20mph-35mph like if my car is jumping, like if you had something on the tire sticking out i went back to the place where i bought them and they said that everything is ok that is balanced and everything but the car keeps jumping suggestions plz

 

I would make them ride in it and tell you that everything is fine. Only time I've ever had cars "jump" is when the tires are off balance... Or, of course, when I'm hitting switches! haha j/k

 

my car does this when it has sat for a long period of time, a couple of days, with out being driven. it is as if the tires get a flat spot, but after driving for a few minutes it goes away.

is you problem continuous no matter how long you have been driving?

I agree, let them drive it and tell you what they think.

 

Take it back and have them Load Force Balance them. Sounds like the tires are not matched up with the rims. You could have defective tires too.

 

i took it back and they said that the balancing os ok that is on 200 something like that and they said that if the tire had came with a bump it would not been balanced

 

Yes, but do they have a load force balancer? I've seen plenty of tires balance out fine but they would ride like crap.

 

May be a set of hubcentric rings would help?

They can help center the aftermarket rims better.

 

what is a hubcentric rim

 

They are the rings that go inside the hub opening on the wheel to ,ske them fit the center of the hub. It basically centers the wheel so the lugs don't have too.

 

Sounds like they are not going to be much help at the shop so you have two ways to go.
1. Pay somebody else to do their job.
2. Do the legwork yourself.

Here is what you do for option 2.
Pick out one of your best stock wheels and swap it with one of your new ones. Drive the car see if the hop is still there, if so swap it with another until the hop goes away.This will go faster if you can determine about where the hop is caused on the car. Take the wheel in question back to them and explain what you did to a manager and you should be good. Could be the balance, defective tire (it happens more than you think), or possibly a bum rim.

 

Great advise! I've actually had to do this before.

 

what is a bum rim

 

Could be a factory defect, shipping damage or something to make it not perfectly round. Might not be noticeable to the eye.

 

Correct, I've seen plenty of "NEW" rims that were not round enough to be used. It's always a good idea to have the rims spun on the balancer and checked for roundness/true before mounting the tires.