How about riding on the side of the road until you get to the trail?

 

where we go we ride from our hotel 2 the trail system.its about 1.5 to 2mi.the sides of the road is trenched 4 drainage plus they are pretty strict about the atv rightaways on the road.if I could do 25-30 mph fairly comfortable I would be happy.i cant plan my whole trip around how they ride on tar but im surprised how bad they are.i may try getting them balanced.i wouldn't care if they vibrated that much,this is more of a bad wobble like im driving on bent rims.

 

did your xtrs vibrate or wobble.i don't mind vibration but these tires wobble like the wheels are coming off

 

There's a few other things that can make your atv wander side to side- tie rods, worn wheel bearings, tired shock / strut springs. But- since you said it was fine up to 50 with your old tires- I'm assuming you bought the tires new and had them mounted- and the shop didn't fill any tire with slime (shouldn't really matter too much if they did as any liquid in the tire should spread equally in all directions as it spins.
The only other logical solution if the above areas are ruled out is rim balancing- although, you really shouldn't feel too much wobble at 15 mph with just an unbalanced rim unless you've somehow really damaged the rim.
Fwiw- even my new 1000 outty max xt with dps and new mega meyhams will be a bit squirrelly at medium to high speeds on tar.

 

the rims are in great shape.i don't think they could damage them mounting the tires/usually bent rims can be seen at low speeds running on the jack,the spin very true.once I get over a certain speed it starts hopping side to side.you really have to hold on to control it going down the road.i cant see this being good for the tie rod ends and ball joints.

 

I would suspect a bad tire. It happens sometimes

 

I don't think moisture in the tires is going to cause the issues you're having. Sounds more like a tire that is out of round (defective) or badly unbalanced which you'll notice more and more as speed increases.

 

i agree.i think one of the rears is defective.i watch it spin on the jack and I can see it start wobbling while the rim still spins true.u can feel the thumping thru the machine.ive had car tires where the belts shifted and caused a similar problem.im gonna contact the place I bought them to try and warrantee the rear tire and maybe get the fronts balanced.if I can solve this issue I think I will like these tires.it does steer better in tight corners.that was my one big issue with the pxt radial