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Recommended tire pressure

Please explain how a few pounds over max would be any more hazardous than running it under pressure where it would be prone to more heat build-up
 
WildThang said:
Please explain how a few pounds over max would be any more hazardous than running it under pressure where it would be prone to more heat build-up
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Tires are designed to run at a certain pressure. The MAX pressure is posted on the side wall of most tires and It is put there by the manufacturer that knows a heck of a lot more than you or I do about the construction of the tire, remember to that when a tire heats up that the pressures can increase anywhere from 2-6 lbs. If it is labeled as the MAX pressure, feel free to run it over that pressure but do it at your own risk.
If you take the max pressure and add your "few extra lbs" to it and after it heats up, it could be above the max pressure by as much as 8 or so lbs.

Over inflation does also make the contact patch of the tire smaller and can effect the handling of the bike.

Under inflation causes excessive heat buildup but we aren't speaking of under inflation here.

I wouldn't run it over the max pressure and choose to run the recommended pressures in all my tires.
 
Wildthang,
As mentioned earlier, why would you even keep the D407 tire? I had mine replaced with nearly 8K on it due to the recall. Even if it was not a recall, I would never exceed recommended pressure in any tire on a MC. You only have two under you, can't afford to lose one. Ride safe. :s
 
I guess I forgot to add this in my original thread (woops)...but it seems there was some discussion at Sturgis this summer from some Dunlop engineers that Dunlop actually wanted that max pressure rating to be around 41psi...but Harley wanted it at 36 (as a compromise to get the best perceived ride quality). This is what making this whole 407 tire issue so frustrating to figure out... Ask anyone with a 407 that has ran pretty close to the 36psi figure and if they have anything close to or over 5K on the tire, tire cupping..either moderate or severe has begun to wield its ugly heard.

On the other hand, I have always ran mine at 38-40 and although probably a little rougher ride, now at close to 6K on the tire, no cupping/noise/vibrations issues has surfaced....


walleye said:
Wildthang,
As mentioned earlier, why would you even keep the D407 tire? I had mine replaced with nearly 8K on it due to the recall. Even if it was not a recall, I would never exceed recommended pressure in any tire on a MC. You only have two under you, can't afford to lose one. Ride safe. :s
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It was not a tire recall...as many would like to think...
 
What's the MAX rating on the side wall of the tire ? I would go with the manufacturers rating moreso than an engineer's hearsay at an event.
 
Given I heard the story second hand, I would agree to a point being hearsay...but to be honest, given my aircraft maintenance background, I would trust the structural intregrity data from the engieer over what the overall manufacture (who is just installing the part) would state...

However, this whole 407/408 tire issue has been soemwhat muddy over the last few monnths. I will state again, I'm confident in my decision to run the air pressure I have chosen as I have not experienced any of the typical tire problems the majority of 407 users had...
 
WildThang said:
It was not a tire recall...as many would like to think...
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I stand corrected as you are right on. It was not a recall. But HD is replacing the tires at no charge under a service bulletin. They just did mine. I did however have cupping issues even though I did maintain correct tire pressure. (38-40 lbs) What was unusual, the cupping was the worse at around 4000 miles. It seemed to be getting better but I still had a low speed wobble. Tire had just under 8K on it and no questions asked. Now it rides much better and there is no sign of the wobble. If I had a 407 tire, I would get it replaced. JMHO.
Ride safe.
 
WildThang said:
Given I heard the story second hand, I would agree to a point being hearsay...but to be honest, given my aircraft maintenance background, I would trust the structural intregrity data from the engieer over what the overall manufacture (who is just installing the part) would state...
Click to expand...

I also have a aircraft maintenance background but your statement "I would trust the structural intregrity data from the engieer over what the overall manufacture (who is just installing the part) would state..."

You have to explain to me just what that means :D

Manufacturers make the part, not install it and I believe very little that I hear second hand.:s
 
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