Had my tires replaced with Kumos a couple months ago to replace previous owner's snow tires he had on it (ride was very stiff and could feel everything in the road). After tire replacement I immeditaly noticed a slight "loping" feel to my ride that became pretty pronounced at around 15-20mph and would stay until just after 45-50mph. Freeway driving at all speeds is smooth and there is no vibration in steering wheel. Kinda feels like I am riding a horse...the car slightly moves up and down sporadically no matter what the road condition is and doesn't matter whether tires are cold or warm although it seems less evident in the afternoon when I go home from work. Tire place checked tire balancing and alignment and found no problems. I hate slow traffic because I feel (and look) like I am on the prairie riding a pony! Any ideas???

Jeff

 

Just because the tires are balanced it doesn't mean they can't be out of round. You could have just got a bad tire (slipped belt or something) or it might not be centered on the rim. A bent rim could also cause this. If a bent rim on the rear of the car was moved to the front when the new tires were put on, a vibration could be more noticeable.

Take the car back to the shop since there is still a problem. As each tire spins on the balancer, watch for any up & down or side-to-side movement. If you notice any movement, watch the wheel to see if the movement is isolated to the tire or if it's the wheel itself that's bent. If it's a tire problem, then chances are it'll be covered by warranty. If it's a wheel, start calling junkyards and searching eBay.

Edit: Don't expect your tires to be perfect. Do to imperfections in the molds, tires will almost always have a tiny bit on runnout.