i did mine pretty toight (although I used the smaller straps, not the cool ones with a ratchet which you can really get to dig into the object). IME the experience isn't holding the wood itself, it's *holding the dolly*
also, since you won't have a tilt point at the back end of the bike... have fun making wide turns XD
not trying to discourage you or be negative about it, just a word of caution ^^
