Mine shakes. But I don't think it is the engine. I can feel it in the front wheel. I don't know about you guys but when I get tires they are all squised and cheaply made to begin with. They pack them so tight so they can ship more in containers from china that they are never going to be straight again. I usually put a tube in them when I get them and inflate it without the rim and just let it sit on the shelf for weeks/months so it regains its shape or at least somewhat. I was also wondering if anyone has ever tried to balance them like on cars? Randy
Great advice JamnJM . Might help a lot of it, or help isolate the problem. I am going to try that. Nothing much you can do with either a bent wheel or a tire out of round. Most of the tires are designed for a riding lawnmower. My murray is smooth all the way with a little chain and motor vibe at high speeds, but a couple I have vibrate pretty good at high speed. Just make believe it is a Harley.
Probably a lot of it would go away if we could run tires designed for a boat trailer. I think they do a better job on their tires. Some more useless info here. On big semi's they don't balance the tires. I found a good tire guy that would do what you were talking about, mark the heavy place and then he would mount the inner tire heavy spot on the other side, so the two together would balance out. Worked really well.
Thanks for all the post. the faster i go the worse it gets. i think its mostly comming from the front end. i have a cheap tractor supply knoby tire on it now. i was going to buy a slick tire from tsc to see if they works any better. the bearing are new and they are the good ones from OldMiniBikes warehouse. im wondering how the guys that drag race the minis or hit speeds of 80mph deal with the problem???