Wayne,
Welcome to the forum. I suppose you have been watching it for awhile before joining. Some call that "lurking," but I don't like the negative connotation of the word. Anyway, I trust you will find useful help and amusing conversation here, I certainly have.
Now, for your question, you have opened up your participation with one of the more intensly discussed topics that just recently slowed down. If you want to learn a lot about swingarm bushes, you might review the topic at
http://www.a7a10.net/forum/index.php?topic=1185.0To encapsulate a bit of the discussion, the bushes are pinched together between the frame plates and, due to pressure on their outside ends, the inside sleeve holds basically steady with the frame while the outer sleeve moves with the swingarm, the liner of rubber between them being stretched with the movement of the swingarm and, therfore, reducing noise and small-motion vibration that would be transmitted from the road to the frame. If you read all the posts in the topic I've pointed at, you will see that it took quite a bit of convincing for me to come around to believing this functional description. I have thought that it might just be intentional that the contact surface area between frame plates and bush is small so that the bush would turn if the swingarm sees unusually long motion. I think that is still an open question. With regard to motion distance, I think you will see under the other topic that the maximum rotation is 8 degrees (I think this was on either side of center, but I'm not seeing the other topic while typing this under your topic, so I'm not 100% sure).
Hope this helps.
Richard L
