Tire Pressure : V-Twin Forum: Harley Davidson Forums

Salty · 07-19-2005, 06:53 PM

I run my tire pressures at 2 psi below sidewall posted recommended. On the Ultra that gives me 38 front 40 back (if you didn't know, back pressure is higher). I have never run the "book" numbers. 20k miles on a Fatboy rear and 13.5k on an Ultra rear before change. Both tires changed while depth gauge in yellow zone (but close enough to red it was time). As much as I hope that info is helpful to someone - does anyone do anything differant that gets more miles on their Dunlops?

Salty

nvsteve · 07-19-2005, 07:04 PM

I run pretty much what the mfg says for loaded and unloaded.
If different it's usually on the higher side.
Don't know if it's right or wrong but always got good performance
and mileage.

sz0wxc · 07-20-2005, 09:15 AM

I run what H-D recommeded and have only has 12K top on the rear and it should have been replaced around 9K. This last time I got like 10K and should have been replaced around 9K also.

The Tourist · 07-20-2005, 11:35 AM

I just got an oil change and was very surprised to find the pressure of my rear tire quite low.

I usually squeeze it leaving my garage. The tire felt rock hard. On my F-150, even at max pressure, the sidewall has a bit of give.

Old dogs, new tricks.

berno56 · 07-29-2005, 05:29 PM

I have run the pressures on my FXSTI by the book since new. I have 13K on the front and rear and still have tread gage readings in the yellow. I am fairly meticulous about checking tire pressure. I would guess I will probably have to change out both tires at about 16-18K miles. I think I am going with Metzlers next time around. I just don't like the way the front tire on the Dunlop rides on grooved pavement.

84FXRP · 07-29-2005, 07:06 PM

I just run the tire pressures as recommended in the Owner's Manual. I have always been satisified with the performance and mileage of the tires. I currently have a FXDI but I've had FLTs and FXRs in the past - the Owner's Manual/Service Manual pressures always seemed to work well for me.

steveusmc · 07-29-2005, 08:07 PM

I run HD/Dunlop recommended pressures in both my tires. One thing I did do that I highly recommend is to go buy a good portable tire inflator pump at Walmart or Autozone or elsewhere. The one I have is a rechargeable nicad battery type so I can carry it in the truck when I travel (has a plug for the power plug in the truck also). One of the problems with bike tires is that people wait too long between checking the pressures. Natural rubber is a relatively poor retainer of air so it's not a real long time before you are down quite a bit and that is hard on the sidewalls and the performance overall.

Sorry to go off on atangent. p.s. Walmart has a couple og great inflator kits.

Semper Fi,
Steve....Pensacola

Biker Bry · 07-29-2005, 08:17 PM

The tire maker only makes tires. The tire pressures on the sidewalls only give maximums. I would NEVER use the max to determine the pressure I run. The bike maker is the one that determines the load rating for the tire. I would only go by what's in the book.
I like the Dunlop OE's, they have alway performed the best IMHO. The perfect combination of grip and durability. Dunlops perform well in rain.
I had used Metzlers Marathons. They out last Dunlops, but I don't think they ride as well, or grip as well.

No flame thrower needed - These are only my opinions.

Vettster · 07-30-2005, 12:47 AM

One other comment to add...
When you figure out the "right" tire pressure, use one and only one gauge to check it. They do vary.

Ride Safe,
Vettster

Geezer-Glide · 07-30-2005, 08:20 AM

Actually, tubless tires will loose air pressure over time. ALL tubless tires do this. The Tourist: Your F-150 has radial tires, and they "Buldge" at the sidewalls with proper inflation. The Dunlops are not radials, so the sidewalls need to be more "square". If you do not run the proper inflation, the tire builds up heat, heat is the biggest enemy of your tire. Get your tire too hot and the sidewall will fail. Can you say "road rash??" If you do not have the proper inflation your tire's tread will not work to it's ability. You do not want to have your tire "wallow" when you are making a turn. This is especially true in the wet. The tread is there to do it's job, and if the side wall is not stiff enough the tread can not grip to it's max. As for me, 40 rear and 36 front. And make sure you check them at least once a week. We only have two tires, not four! And oh yea, vesters right.... use the same gauge!!!!

Salty · 08-01-2005, 11:46 AM

Crash - bike was used for commuting, interstate travel, 5 days a week 70-75 mph, 80 miles round trip. Weekends were back roads so I could wear the sides too...

Salty · 08-01-2005, 11:50 AM

Biker Bry - What does the H-D owners manual tell you to run your Metzlers at? Don't they post a higher max pressure than the Dunlops? I spoke with a Dunlop rep regarding the 2 psi below sidewall max and his response was - if it works.
Salty

goingsking · 08-01-2005, 12:19 PM

A point that Geezer-Glide was stating, use the same instrument to measure the pressure. My problem is getting on that is accurate. I used my suspension pump hoping that it was accurate to figure out the proper pressure on my other gauges. Remember back in surveying when you had to calculate the correct length on metal measuring tapes for temps, need to do that for air pressure

nvsteve · 08-01-2005, 12:22 PM

The Metzeler website has recomended air pressure for their tires.
Just look up your bike.

Kags · 08-01-2005, 01:17 PM

Its funny how some folks leave there bike in gear at a light to "be safer" then over inflate there tires. You are ALWAYS on your tires, and spend little time at stop lights (inless you live in...). Point is, the reason for Mo Co specs on tire psi is saftey. Contact patch is effected when you over inflate a tire. The max anyone stould go for extended milage is the 10% rule, so 33 max (cold) on a 30 psi (cold) tire not 40 psi for a 30 psi tire (I have heard folks going 10 psi over). Even so you will lose a little contact patch @ 10% over.