Here's what Dunlop has to say.
Tire Tips
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Overinflating tires does not increase load carrying capacity, but will result in a hard ride and accelerated tire wear in the center of the contact patch."
Nowhere in the document does it say that inflation to the sidewall pressure, rather than MOM pressure, constitutes overinflation.
The sidewall DOES however, state, for example, "Max load 908lbs @ 40psi cold"
The load rating IS impacted by inflation level, and that 77H tire may only be a 74S at 32psi
This statement is supported in the reference:
"Keep in mind that hard cornering, passengers, heavy loads and sustained high speeds will require higher pressures (
up to that indicated on the sidewall)."
Both the sidewall load rating AND pressure are max, and exceeding either or both can cause tire failure.
You have NEVER seen anyone on this forum recommend operating tires in excess of sidewall inflation limits.
Furthermore:
"For high-speed, fully loaded or dual-riding touring motorcycle applications, inflate front tires to maximum recommended by vehicle manufacturer for Dunlop fitment and rear tires to maximum load inflation pressure on sidewall.
Rear touring tires must be inflated to a minimum of 36 psi for light to medium loads and 40 psi for dual riding and other loads. Never exceed maximum load indicated on tire sidewall or vehicle capacity load found in owner's manual."
One again... MINIMUM 36psi for light to medium and 40psi for 2-up.
The 2006 Vulcan 1600 Nomad MOM indicates 28psi front, 36psi rear.
Your comment "may get someone hurt" is completely off-base. In fact, running 2-up on an underinflated tire may result in tread separation.
"Always keep the motorcycle manufacturer's recommended air pressure in both tires. This is an important requirement for tire safety and mileage. Your motorcycle owner’s manual will tell you the recommended cold inflation pressure.
The pressures stamped on the sidewall of the tire are only for maximum loads. On some occasions, these pressures will also be the manufacturers recommended settings as well."
"
Over-inflation or extreme tire pressure will impair your riding comfort and decrease the contact of the tire with the road.
The manufacturer's information is the minimum values only. With luggage or with a second rider the rear tire needs an extra 0.2 bar, and for high speed riding the pressure of the front tire should also be increased by 0.2 bar."
"Increase rear tyre pressure by 0,2 bar / 3 psi when riding with a passenger or with very heavy load. Insufficient inflation pressure causes tyre flexing and overheating that may lead to internal damage. Overinflation impairs riding comfort and stability and can result in uneven wear."
Also, take into account that different tire types from even one manufacturer may have different recommended maximum inflation pressures. Example, some Avon Venom series with reinforced sidewall carry a max inflation of as high as 47psi. The reinforced sidewall combines with the higher pressure to increase the load rating of the tire.
Should this tire be run at the same pressure as a tire that carries a manufacturer's max of 42psi?
I think that ought to be enough to make my point, and that is "Anyone telling you to always inflate your tires to the max pressure printed on the sidewall is wrong", always follow the info in the owners manual.
Completely wrong.
Anyone telling you to inflate ABOVE the max pressure indicated on the sidewall is dangerously wrong. As indicated by Pirelli and Dunlop, MOM is a minimum, the sidewall is a maximum.
If you CALL Metz and ask what is recommended for a Vulcan 1600 with their 180/70R-16, they will tell you 42psi.
Furthermore, Navy testing at Pax river show a direct correlation between tire pressure and the speed at which hydroplaning will occur. I don't recall the exact formula, but a typical passenger car tire at 28psi will begin to hydroplane at 55mph. The same tire and road conditions at 36psi moves that speed up to 70mph.
I have ALWAYS run max sidewall inflation levels on my cages unless airing down for off-road use, and I have never experienced uneven treadwear.... but I have been able to get 60,000 miles out of a cheap set of Sears tires that were rated for 40,000 miles.