Run a mid cage but not for clearance issues. There are differnt length cages to compensate for chain wrap. Chain wrap=(big cog-small cog) + (big ring-small ring). Most derailleurs have a chain wrap number given to them. Stay with in that number unless you are really careful and lever cross chain. I use a mid cage because it keeps the chain tighter than a long cage therefore giving me more accurate shifts. I also shorten my chain by 1 link and never cross chain. This combo will keep you shifting through anything, mud, dirt, snow.