I had new a new front and back put on, and a tune up. Rode away, and the front of the bike vibrates in an up/down motion at slow speeds, especially when you change speeds. Brought it back twice, and they re-balanced the front tire. Still nothing. The third time they replaced the tire with a different kind - STILL shimmies. I am bringing it back and they will KEEP the bike until they find the problem, but I am wondering if anyone else has experienced this, or if you may know what the issue is.
Racing tires are very soft compound, wear VERY FAST. If you do not have proper width rims, will have a very poor contact patch, as the racing tires are normally for wider rims, and a street rim makes them too round where they contact the street, there fore, do not have as much rubber on the road as a proper street tire. Also - expensive. The factory recommended tire size, in a brand name tire, Dunlop, Avon Michelin, Metzler, etc, not cheapies, will handle best, and give far better service than a 'racing' tire. If you are racing, of course, all things turn around, the things which make a racing tire unsuitable for the street, mostly are of no importance on the track, as long as you have proper wheels, the wear factor is not important, the greatly increased traction is crucial. And the wheels must be proper width for the tire you use. Go Fast, Go Safe, Go Smart. Tomcotexas.
Every motorcycle tire I've seen has a yellow stripe on it ( like a magic marker mark). That mark should line up with the valve stem where it comes out of the rim. It's a balance mark, and it's important that they are lined up. If not that, I would say a bent rim.
Three things cause that type of movement. 1. Improper air pressure. 2. Improper balancing. 3. Bent / damaged rim. If it wasn't happening before and it's happening now, they are responsible.
