I havent written for a few years but to my memory the type of tyre has a big input on this. One road test I recently read suggested that most bikes (British or Japanese) that have a older fashioned block type, tread (these are of course newer than the ribbed front tyre of those in the day),tend to wobble at 50mph on de-acceleration. No body seems to have come up with a definitive answer but on my next tyre change I will try an Avon(non block type tread) this tyre has a modern day tread pattern.(no idea what to call the modern day tread pattern maybe race style or is it radial?)
What ever just hang on tight until you find a solution and let us know.
