I made (modified) what may become my favorite bike-related tool: a light-weight, compact adjustable wrench that will live in my seat bag and fits all the axle nuts, seat-clamp nuts, etc., on my collection of behind-the-times bikes. (Only one has QR axles front and rear, and one is fixed gear and can't have QR on the rear wheel.) I had to file the jaws of a 4-inch-long wrench that couldn't quite span the axle nuts. It should still be strong enough since I won't need to do major torquing with it. Without this tool - or something bigger and heavier - I couldn't fix flats on the road.