Hello Ed, I have used nylon 1/4"-20 nylon bolts with good success..... on some planes. I think they are great if you can get the pattern correct and especially the weight of the plane vs. the number of bolts. Examples: I have a Midwest Starduster, (like a 4*), and it weighs 5.5 lbs. I have three 1/4" bolts in a trianglar pattern the the single bolt to the front. I have never lost the gear "needlessly". On the other hand... I have a GP Spacewalker with aluminum gear on the chin block and have the SAME pattern and number of bolts. (I took the factory gear off the wing). This plane weighs 9.5 lbs. I am going to either change the pattern, (add a bolt and make it a rectangular pattern), OR, put in a steel bolt in the front hole of the triangle. This plane has lost the gear 2 or 3 times when it wasn't that hard of a landing. I will still use break-away LG, but I am finding you do have to make minor repairs to covering on some break-aways. I sustained the most damage on my Spacewalker last fall. It tore a chunk of wood out of the center wing section, poked some holes in the bottom stab, flipped UP and actully broke the lowest stringer and damaged the covering in that area too. I would rather fix that than tear out the LG block and part of the fuse. If I would have "GUESSED" better, and took the plane's weight into consideration, my break-aways probably would not have happened. I have had some come off with absolutely no damage. It is all luck when it comes off.
As far as grass fields, I put on the biggest wheels I can without it looking goofy.
Just a word here about tip overs. I have mounted my gear forward of the "accepted placement" on 3 planes now, with NO problems of ground handling or tip overs. I still use up elevator... to hold the tail down.... but it is a LOT less touchy. I know some guys will freak out knowing how much further forward. . On the average.... my axles are about 1" forward of the leading edge, instead of even with it. I know there are some that won't belive I have no problems with this set-up, but it truly works great for me.
PS. I never have had a problem with the tail not coming up either. I have attached a profile shot of my Starduster. This is the factory supplied gear that is actually supposed to have a "swept back" look. I turned it around..... notice the axle placement. I have flown this plane all summer with no take off or landing problems due to the gear. (maybe my thumbs though) ... lownslo