Here is a very accurate method of aligning your wheels. Many people have posted a different method on the internet which uses the front tire to wrap the string and become the base but it is not nearly as accurate and requires measuring of many distance points. The method I am describing today does not require much more than a "visual" look to determine if the wheel is in very close alignment. It does require good vision with good depth perception but the method is very accurate, not particularly time consuming and requires little to no special tools to perform the inspection. To adjust the wheel alignment requires nothing more than the same tools you would use to adjust the chain.
Recommended tools to adjust chain and align the wheels:
Here is a drawing of this method.
Here is a front view of the method after it is all set up.
Place the motorcycle on flat level ground on it's centerstand if it has one. If it doesn't, then a swingarm work stand is the next best thing. Place transmission in first gear to prevent rear wheel from turning.
Next, attach one end of the line to a heavy tool like a 2.5 lb hand sledge hammer. Now, measure off about 20 ft. or so of line and cut it. Place one heavy tool with one end of the string attached to it on the ground a few feet ahead of the front wheel and slightly off to the side. Run the other end of the string along side the motorcycle then around the rear tire. Be careful, the string line should not contact anything other than the rear tire. If it is fouled by the centerstand or work stand, then your straight edge is no longer straight. If you are careful in selecting the line's path and use the supplied pictures as examples, you should be able to run the line between the swingarm spring (on the FZ1) and the swingarm and not have any fouling to alter the "extended straight edge".
Take care with the path of the string so it does not become "fouled" by the centerstand and centerstand return spring. There is sufficient clearance if the string is low enough on the rear tire.
Use a piece of duct tape to secure the string to the rear tire and run the remainder of the string up along the other side of the motorcycle and past the front wheel. Attach another heavy tool to the free end.
Now, remove any slack the lines have in them on both sides. Go back to the rear wheel and take a look at the string at the widest point of the front portion of the rear tire. Move the strings in front of the bike on both sides until the string is barely touching the rear tire where it passes the front widest portion of the rear tire. What you are doing is creating a "straight edge" and placing it along both sides of the rear tire and extending that line past the front wheel. When you have all of this set up, then the front wheel should be perfectly centered between the two strings passing the front wheel. If if isn't centered, then carefully lift or slide the front wheel to center it between those two strings. With the front wheel centered and pointing straight ahead so the distance is the same on both sides of the front widest portion of the front tire and the rear widest portion of the front tire then go back to the rear wheel and see where the strings touch the rear tire.
The distance should be the same on both sides of the front tire at 4 separate points. Right and left front widest portion and right and left rear of front tire widest portion.
When the front wheel is centered between the two string lines, the string should be barely touching the widest portion of the front section of the rear tire on both sides of the motorcycle. If it is not, then use the procedure to adjust chain slack or tension. It's quite possible that when you loosen the axle and axle adjustment nuts and bolts, you will disturb the string lines and may have to reset them up. Do not over tighten the chain. Remember, the axle adjuster bolt pushes the axle back on the side it is on. As an example, if there is a gap between the string and tire on the chain side, you will most likely have to move to the other side (brake side) adjuster and loosen it so the axle can be pushed forward on the side opposite of the chain and where the gap exists.
When you are confident you have the chain slack and alignment properly adjusted, recheck all points of your string line prior to and after tightening all nuts and bolts.
When you have aligned the wheels in this method, you should not have to do it again until the rear tire is changed. In addition, when adjusting the chain tension you should only need to loosen the axle nut enough to allow minimal movement. Then turn each axle adjuster bolt the same amount. I use one "flat" or 1/6th of a turn each side. Rarely do I need to turn it more than two flats when I adjust chain slack and this is about every 2000-3000 miles or once, maybe twice between tire changes.
Hopefully, this has been helpful.