From the Dunlop Tires website:
http://www.dunlopmotorcycle.com/infocenter_tiretips.asp?id=31#tipDunlop technical personnel have attended touring rallies all over North America to collect vital data and give instructional seminars. What we have observed at these rallies alarms us; many touring riders are not following proper tire maintenance procedures. The requirements for proper tire usage are not complicated, but they do require consistent attention. Owners and operators of motorcycles should closely monitor vehicle loadings to insure they are within the maximum loads and corresponding inflation pressures for their tires. This basic load and pressure information is clearly stamped on the tire sidewalls.
The tire does not support the load-the air pressure does. The manufacturer's ratings for the maximum load and inflation pressure are critical tire design elements. If not observed, the handling and performance of your motorcycle will be greatly affected. We have checked inflation pressures at several touring rallies and
found a high percentage of rear tires to be underinflated. In addition, weight checks of the rear axles of these motorcycles indicated a number of tires were loaded beyond maximum capacity.
Our inspections have not been limited to those cycles fitted with Dunlop tires; the situation exists for all brands of tires. Regardless of the make of tire, this is a serious problem. Riders of motorcycles with significantly underinflated and overloaded tires will experience handling and steering difficulty. In addition, this abuse will result in disappointing premature tire wear and may cause catastrophic tire failure.
The addition of accessories, cargo, and dual riding to touring motorcycles aggravates the problems of overloading and underinflation. The excessive flexing that results from underinflation or overload causes buildup of internal heat, fatigue cracking and eventual carcass breakup resulting in complete failure. A consequence of such failure may be an accident with serious personal injury or death. The appearance of stress cracks in the tread grooves is one indicator of overload and/or underinflation. If you find evidence of tread groove cracking, you should remove and replace the tire immediately. This damage is permanent and non-repairable.
Our inspection of tires of various style and manufacture at rallies and our subsequent testing have confirmed that underinflation (and/or excessive load) causes tread groove cracking and can result in more serious damage within the tire body. Uneven wear may also accompany underinflated use. Failure to heed these visual warnings can result in tire failure or blowout.
The use of trailers can also contribute to tire damage and touring motorcycle instability. Although most motorcycle manufacturers recommend against their use, a percentage of the motorcycles we have inspected were so equipped. The trailer tongue weight added to an already heavily laden motorcycle can fail a rear tire. The percentage of overloaded motorcycle rear tires found during our inspection would have been higher if trailer tongue weight had been considered. The forces of rapid acceleration and deceleration may also multiply the effects of trailer tongue weight.
To get the maximum safe use out of your tires and maximum touring enjoyment you should:
- Properly maintain all aspects of your vehicle in accordance with manufacturer's recommendations. Read and reread your motorcycle owner's manual.
- Never exceed the loading and accessories restrictions found in your motorcycle owner's manual, or the maximum load displayed on the tire sidewalls. Know your loaded vehicle weight!
- Check air pressure at frequent, regular intervals, particularly just before and during long trips. Always use an accurate tire gauge* and check pressures only when the tires are cold (i.e., wait one hour after running). We have found many cheap gauges to be off more than 5 psi, so be sure to use a top quality gauge and preferably one that retains the pressure reading until reset!
- Inspect your tires as often as possible. Look for irregular wear, any signs of cracking in the sidewalls and tread, blisters, knots, cuts or punctures. Immediately remove and replace damaged tires.
If in doubt, ask your motorcycle tire dealer to check your loading, inflation and tires. Remember, your tires stand between you and a serious accident.
For touring motorcycle loading, follow these general guidelines:
- Light loads-single rider with some luggage (up to 200 lb. total)-minimum tire pressure of 32 psi front and 36 psi rear must be maintained.
- Heavier loads-dual riding and/or luggage (from 200 lb. total up to maximum motorcycle capacity stated in the owner's manual)-pressure of 36 psi front and 40 psi rear must be maintained.
Please Note:
For any dual riding or fully loaded use, 40 psi must be maintained in all Dunlop rear tires fitted to touring motorcycles.
In addition to following these recommendations, notice what your tires are telling you while you're riding. If your steering response is slow or mushy, or if cornering and braking response is heavy, there's a good chance your tires are underinflated. Vibration or wobble may signal that actual tire damage has occurred and failure is imminent!
