As the world leader in motorcycle tyres, Dunlop continues to be concerned about the lack of attention paid by many cyclists to proper use and maintenance of their tyres, particularly when fitted to motorcycles intended for touring.
Dunlop 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 tyre maintenance procedures.
The requirements for proper tyre 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 tyres. This basic load and pressure information is clearly stamped on the tyre sidewalls.
The tyre does not support the load-the air pressure does. The manufacturer’s ratings for the maximum load and inflation pressure are critical tyre 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 tyres to be underinflated. In addition, weight checks of the rear axles of these motorcycles indicated a number of tyres were loaded beyond maximum capacity.
Our inspections have not been limited to those cycles fitted with Dunlop tyres; the situation exists for all brands of tyres.
Regardless of the make of tyre, this is a serious problem. Riders of motorcycles with significantly underinflated and overloaded tyres will experience handling and steering difficulty. In addition, this abuse will result in disappointing premature tyre wear and may cause catastrophic tyre 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 tyre immediately. This damage is permanent and non-repairable.
Our inspection of tyres 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 tyre body. Uneven wear may also accompany underinflated use. Failure to heed these visual warnings can result in tyre failure or blowout.
The use of trailers can also contribute to tyre 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 tyre. The percentage of overloaded motorcycle rear tyres 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 tyres 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 tyre sidewalls. Know your loaded vehicle weight!
- Check air pressure at frequent, regular intervals, particularly just before and during long trips. Always use an accurate tyre gauge* and check pressures only when the tyres 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 tyres 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 tyres.
If in doubt, ask your motorcycle tyre dealer to check your loading, inflation and tyres. Remember, your tyres 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 tyre 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.
For any dual riding or fully loaded use, 40 psi must be maintained in all Dunlop rear tyres fitted to touring motorcycles.
In addition to following these recommendations, notice what your tyres 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 tyres are underinflated. Vibration or wobble may signal that actual tyre damage has occurred and failure is imminent!
If you conscientiously follow our recommendations, you will enjoy better, longer, and safer tyre performance and many, many miles of touring pleasure.