I have searched and studied but would like reassurance from the inmates before I spend the money and time. I plan to mount knobbies on my 990 for a 1200 mile cross country Nevada ride with the Dirtdevils of Reno in May. There will be some nasty mud, water to negotiate and sand, rocks, steep at times. I will be taking it easy on the pavement and want all the dirt traction and rock handling I can get. At this time I am planning on TKC80 front and a Terraflex or Tractionator rear. Thanks fellow desert riders. Questions: 1. Where can I buy at a good price? 2. Considering I run a 150 Mefo now, is a 140 ok for my stock rear wheel? 3. Is this tire selection what you would try? If not what?