http://www.trailrideraustralia.com/viewtopic.php?f=36&t=359 Read the 1st page but not sure what you are trying to point out? From my bike prep notes. Done: Starter: 1.63 lbs Done: Starter drive gears: 1.05 lbs Done: Tank mount bracket: 0.39 pounds with the 4 bolts <-- needs reinforcement though Done: Starter switch and harness to right side rad mount 0.11 lbs Done: Boil off vent hose, tank to under bike, 0.15 lbs Done: Head light assembly 1.45 pounds Done: Reflectors: 0.72 pounds Done: Trip computer assembly: 0.88 pounds Done: Battery: 4.60 pounds Done: Snorkel: 0.46 pounds, with screws Done: Starter relay, cables, isolator rubber, other relays, etc. 0.88 pounds. Done: Boil off bottle and connector hose: 0.52 pounds Done: Battery tray, boil off bottle fender plastic, ECM rubber isolator: 0.44 pounds Done: Breather reduction of starter port. 0.13 pounds gross, about 0.12 pounds net Done: Throttle body harness holder. 0.06 pounds Total 13.44 pounds. 260 - 13.44 = 246.56 pounds, dry. In progress. - speedo drive 0.55 pounds, 0.45 pounds net - radiator louvres, 0.3 pounds each, 0.6 pounds total - regulator mount, 0.13 pounds - kick stand 1.16 pounds, plus lighter left footpeg mount Total: 2.36 pounds 246.56 - 2.36 = 244.20 pounds Next up: - starter clutch and gear, hoping for 1.5 pounds, lighter flywheel as well - muffler, hoping for 2.5 pounds - Titanium shock spring, hoping for 1.25 pounds - Aluminum rear sprocket, nearly 2 pounds - newer YZ swingarm 2.5 pounds Total = 9.75 pounds. 244.20 - 9.75 = 234.45 This is without handguards, rad guards and rad braces. There are other weight reduction possibilities too. I bet one could get a WR450 down to 230 pounds dry, a loss of 30 pounds. By dry, I mean with an empty fuel tank but otherwise ready to ride. I'll write this up in detail in a thread if there is interest. I took pictures of everything as I did it. You've done your home work, and work to boot. Why did you go this route and not just start from the Yz platform?