I have a Stealth Fighter. Since new, if I run with the wheel off the ground, testing, it exhibits what I consider to be excessive shaking at the higher RPMs. Recently, I replaced the stock rim and tire with a good quality motorcycle rim and tire. I trued the rim to within .008 tolerance for both run-out and circumference. On reassembly, the exact same condition, excessive shaking at higher speeds exists. I really don't notice this when riding, but it is strange that the shaking is so severe. Anyone else seen this, corrected this? Is it balance or the hub motor quality? I have a motorcycle and on the center stand, wheel off the ground, I can go as fast as I like without this shaking. Help please.