I have used nothing but pull-pull on both elevator and rudder on all my 1/4 scale. I use nylon coated fishing leader material routed thru nylon tubes. Some are over 12 years old with heavy use and none have ever worn thru the tubes. I even use the tubing to route the cables in something other than a direct line with no problems. A good source of tubing is Hobby Lobby, you can get 25 ft. rolls rather inexpensively. Chadderbox, I'm curiouse, I've never heard of spars in a fuselage, do you mean stringers or do you mean the bulkheads?