Fixing A Motorcycle Flat Tire
Unfortunately, at some time every motorcycle is bound to have a flat tire. Repair procedures are basically the same, whether you're caught with a flat while out riding or have discovered the results of a slow leak at home in your garage.
1. Put the machine on its centerstand or prop it up somehow and remove the wheel.
2. Be careful with the accessory attachments such as mechanical and hydraulic brake linkage, speedometer cables, chains, and torque stays. Also note approximately where the chain adjuster was set so you can get "back in the ballpark" when reinstalling the wheel.
3. Completely deflate the tire by removing the valve core. Then stand on the tire with your heel to break the bead loose from the rim.
4. Lubricate the bead area with a suitable rubber lubricant such as hand soap, soap suds, anything but a petroleum product, which will deteriorate the rubber.
5. Now you're ready for the tire irons. Not screwdrivers, crowbars, wrench handles, or chisels: but properly prepared, special-purpose tire irons. Make sure that the business end of the tool has been ground or filed smooth so that there's no chance of ripping or cutting the tube.
6. After removing the valve stem retaining nut, slip a tire iron under the bead beside the valve stem. Simultaneously press the bead opposite the valve into the recession in the center of the wheel. Pry the bead of the tire over the lip of the rim.
7. Use another tire iron to take another "bite" a few inches to the right of the first. Now go a few inches to the left and pry again, being careful not to damage the tube. Continue around the tire until the bead is completely outside the rim.
8. Remove the tube carefully. Re-inflate the tube and look for the leak, either by listening or submerging the tube in water. If the leak point is a cut or pinch rather than a puncture, the tube will be unreliable even when patched. In fact, you're always being a gambler when patching a punctured tube. The best approach is to use a new tube. Figure it this way: a new tube doesn't take up much more room on your touring machine than a tire patch kit and saves a lot of risk and grief. For a youngster's gravel pit bike, however, patching tubes saves money.
9. Locate the spot on the tire rim assembly where the leak occurred. Remove the nail, glass, wire, or thorn that may have caused the flat, and patch the inside of the tire casing if the inner surface looks as if it may cause more trouble in the future. If the leak is on the inner circumference of the tube, check for protruding spokes that can be filed down or a defective rubber rim strip that can be replaced.
10. Reinstall the tube after inflating it enough to give it a limp shape.
11. This time begin your tire-iron work opposite the valve after you've lubricated the rim, bead, and tire irons. Proceed gently and evenly around the bead until it is seated.
12. Make sure the tire, tube, and wheel are correctly aligned; that is, the valve stem should poke straight out of the wheel, not at an angle. If the tire has a dot mark that should align with the valve core for balance purposes, line it up properly.
13. Re-inflate the tire being certain that the circumference of the tire coincides with the rim. There is a thin aligning seam around the tire that is used for this purpose. To correctly seat the tire, sometimes you must pump it up to 60 or 70 pounds (4.1 - 4.8 bar), then deflate it to the proper pressure. Other times you must break down the bead, lubricate it, and re-inflate the tire to gain proper seating.
14. When replacing the wheel and tire assembly, be sure to adjust the axle alignment and chain tension correctly, and to re-attach all other fixtures securely.