I like the clean look of #9 and the motion invoked by the design. Perhaps incorporating a tire tread "watermark" into the red background of the logo? Also - perhaps trying an Harley orange?
I like the wrap around tire, but we lose the movement of the outside rings. What about going back to #9 and having the tread design run across (in front of) the red and behind the text from the upper right towards the lower left - perhaps in a light grey, or darker red or something that is only slightly noticeable? (sort of blends in?)