Thanks Road Agent, but I couldn't find too much technical info on that site.
Thanks again Henry, you have been very informative with some of the other questions I have asked.
I agree hairpins look more "t-bucket", but I have read some info that they are limited in thier movement and cause the frame to twist in some extreme cases. The batwings I saw at speedway were welded to the tube axle but surely there are some that bolt on.
Thanks again