I use Serfas Drifter S tires. I think they are the best motored bike tire made. Inverse tread, 4 layers of flat protection. I ride at 40 mph for 10 miles just to get to town. I think you need to get rid of the weight inside the tires. A Drifter S tire is 40 bucks they come in 1.75 and 2.0 width. Try one with just a hvy duty tube. No slime tubes. No flat protection strips. Make sure the hole for the stem has no sharp edges. Inflate to about 40 lbs and look at the stem. If it isn't straight drop the pressure to about 5 lbs and work it round till it is straight then ride at 60 psi. Since I switched to these tires I have had zero tire problems. With the inverse tread they are very smooth rolling and vibration free. The S stands for survivor series. I have about 400 miles on them now and they are showing almost no wear but they still have great cornering traction. These are far and away the best bike tires I have ever rode on.