2. To check the alignment you will need an assistant, a length of string or a perfectly straight piece of wood and a ruler. A plumb bob or other suitable weight will also be required.
3. Place the bike on the centrestand (where fitted) or an auxiliary stand. Measure the width of both tyres at their widest points. Subtract the smaller measurement from the larger measurement, then divide the difference by two. The result is the amount of offset that should exist between the front and rear tyres on both sides.
4. If a string is used, have your assistant hold one end of it about halfway between the floor and the rear axle, touching the rear sidewall of the tyre.
5. Run the other end of the string forward and pull it tight so that it is roughly parallel to the floor (see illustration). Slowly bring the string into contact with the front sidewall of the rear lyre, then turn the front wheel until it is parallel with the string. Measure the distance from the front tyre sidewall to the string.
12.5. Wheel alignment check using string
6. Repeat the procedure on the other side of the motorcycle. The distance from the front tyre sidewall to the string should be equal on both sides.
7. As previously mentioned, a perfectly straight length of wood or metal bar may be substituted for the string (see illustration). The procedure is the same.
12.7. Wheel alignment check using a straight edge
8. If the distance between the string and tyre is greater on one side, or if the rear wheel appears to be cocked, refer to Chapter 1 and check that the chain adjuster markings are in the same position on each side of the swingarm.
9. If the front-to-back alignment is correct, the wheels still may be out of alignment vertically.
10. Using a plumb bob. or other suitable weight, and a length of string, check the rear wheel to make sure it is vertical To do this, hold the string against the tyre upper sidewall and allow the weight to settle just off the floor. When the string touches both the upper and lower tyre sidewalls and is perfectly straight, the wheel is vertical. If it is not. place thin spacers under one leg of the stand until it is.
11. Once the rear wheel is vertical, check the front wheel In the same manner. If both wheels are not perfectly vertical, the frame and/or major suspension components are bent.