well its an issue to me. it might be normal. i have a 2008 yzf 450 and i put new crank bearings along with the hot rods stroker crank and now it vibrates. i have intalled crankshafts before and i always had to press the crank into the bearing on the one side. but not on this hot rods crank it slid right in. so now it vibrates when its reved. is it normal? should i be concered? i hope its normal and all stroker cranks vibrate. i appreciate any feedback.