i have a 3" extension kit on my girls blaster, and its 1" thick aluminum. no problems. it might not look as cool as a $1000 aftermarket swingarm, but works perfect. i ride it hard, and its like new. i bet the swingarm will bend before the extension. i'm sure all extension kits aren't the same, but mine is sik strong. if you want a pic, i can put one on 2nite. dont know who made it though, cause i got the swingarm/axle/carrier all used/assembled off ebay. and yes, it doesnt wheelie nearly as easy, thats why i got it, i dont want her flippin it n gettin hurt, but i can still put it straight up using the clutch.