hee hee
Now I'm gonna blow yer mind some .... you can't trust them little marks on the axle to be the whole story as it assumes your swing arm and bearings are all "factory nominal" and I am afraid that jest ain't so on a bike with over 5 years on it.
Some are saying "chase the belt tracking" and that is fine if you want to do that -- the outer hub where the big pulley rests runs on a big assed ball bearing that is trapped between steel shoulders that run directly on the axle and the ball bearing inner race is pinched by your all yer axle tightening forces and it isn't going anywhere.
But ....
It is a BIG ball bearing that has a lot of radial and lateral clearances that multiply out with distance to some clearly apparent movement on the big pulley (jest grab the sucker and wobble it some iff'n you don't believe me).
"Tracking the belt" is a bit of a waste of time, ol' Serowbot has the right of it. Instead, as you run down the crown (center of the drainage hump) on a straight level section of good paved road
take a look at how your handle bars sit relative to everything else.
You can't study your rear end while riding, but you sure can see the front end if it is cocked any at all. As a matter of fact, now that you have looked you noticed that yours is sitting slightly catywampus to everything else on the bike.
Your front and rear wheel WILL run in parallel to each other on a level straight upright condition (road forces say this must be so and you cannot stop it or avoid it).
First, move your butt around on the seat and see if it makes any difference. Some of us jest sit funny and it does play in this equation.
If not,
then adjust your rear wheel to correct the cocking of your front wheel and you will achieve the mythical "good alignment" of your bike.
NOTE: this trick applies equally to wrecked front ends or warped frames or cocked swing arms. No matter what, the wheels run in parallel but on a tweeked bike they may be offset slightly to one another (which causes no wear or other issues, btw).
Now another shocker to those who didn't already know it, Suzuki set the rear wheel up offset a bit to the front wheel a little bit to begin with. They had to make some room for the big pulley's width.
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I now declare this alignment war to be potentially started -- get yer measuring tools and your machine guns and be ready to validate your opinions with something other than 'jest saying so'.
We still have never resolved
"the correct way to align your rear wheel" although some have proposed a 20 foot long mark on the floor and some have proposed steel straight edges and some have proposed measuring accurately to the hub of the swing arm on both sides.
Pick yer camp and get yer shovel out and start diggin' yer foxholes