Something i saw on Dirt Bike TV was that tires have a yellow dot marking the lightest spot on the tire, rotational wise, so on the show the showed putting that yellow mark at the valve stem cause the valve stem is a heavy spot on the wheel/tire.. to kinda balance it out... heres something from another site....

Traditionally, the valve stem is thought of as the heaviest point on the rim. So tire manufacturers mark the lightest point of each tire (usually with a paint spot on the sidewall), and you're supposed to line the paint spot up with the valve stem. Except that the valve stem isn't always the heaviest spot on the wheel. So it behooves you to put the wheel on some balance stands and find its true heavy spot. Once you do, you line the marked light spot of the new tire up with the heavy spot on the rim. By lining the light spot of the tire up with the actual heavy point on the rim, you often need less taped-on weight to balance the wheel -- and sometimes none at all.
Just something i didnt know when doing my first tire, it didnt make that big of a difference obviously, and this article is from a sport bike so im sure wheel balancing is alot more important because of the speed they go.

 

Hmmm interesting, I was told by the parts guy that the yellow mark was a quick way to tell DOT tires from off road tires at a glance. Now I'm confused. But then again I'm always confused so that's not a very good gauge.

 

all tires... dirt bike, sport bike, and even tires for my truck.... look at your tires. if they are new enough to still have the paint..

 

Knowing that, you could use that information to help offset the added weight of a rim lock.