We all know the vehicle manufacturer knows better than the tire manufacturer, just ask Ford, or has everybody forgotten that situation?
Anyways, you do what you think is right and I will do the same.

 

I expressed my opinion that the words on the tyre would better be left off. It is also my opinion those words are misleading, as we have had demonstrated in this thread by some of things that have been said. I have previously described what they mean, according to a tyre maker.

If in doubt about the correct pressures for your bike, write/email/phone your preferred brand of tyres. Which is where I came in!

 

I think most people are not aware that a tire is actually a part of the suspension system in a sense. A tires job is not just for traction and rotation of course, it has to absorb road shock and work in conjunction with springs, shock absorbers, and steering components.

If a tire is underinflated, we know what happens - bike feels squirmy, difficult to steer, and tire wears unevenly and prematurely and eventually fail due to excessive heat (ex: Ford explorer recall as 8541 reminded us about) and we know how safe that is!

If a tire is overinflated, to some if feels better as the ride is firmer and you may feel the road better but whats really happening again is uneven, premature wear and now because the tire flex is gone, suspension, steering, and related components are now being pushed past their recommended stresses. This as well can cause an unsafe vehicle because now other components start to wear prematurely (ex: shocks, steering head bearings, etc.) and can cause an unsafe motorcycle also.

Thats why IMO its better to run the Mfg. recommended tire pressure for the bike and not the maximum tire pressure on the sidewall of the tire. There is always going to be a debate on this and I'm not trying to tell anyone what to do but if you look at the entire motorcycle in a whole and how things are designed to function, it just makes sense.

 

I applied factory air pressures on my first set of tires, results were, wore out front premature due to factory recommended pressure. Front tire ended up cupping, creating handling issues. I now run 38 front and 40 rear. Not only handles the road with better feel, but will last a little longer too.

 

You are probably 100% correct for your particular air pressure gauge. But, as I tried to point out earlier on this subject, air pressure gauges aren't often calibrated! I gathered all of my various tire pressure guages together for a shoot-out (at least 6 to 10 of them) and I didn't find two that agreed with each other.

In other words, you discovered, through trial and error, what works best for your gauge, that is smarter than most riders even think of doing. However, that doesn't translate to me having the same experience for my tires at the same indicated air pressure (on a different gauge) for my tires. My gauge could be showing 35 PSI while yours is indicating 38. Perhaps you are really running 35/37, then while when cupping you were running even less.

 

I'm running 36psi front and back with a Avon 90/90-21 front, and a Screamin Eagle Dunlop 180/60-17 rear.

Wasn't that the Ford Explorer that was designed to flip over when you get a flat? Didn't Ford turn it around and blame the tire manufacture?

 

You can't have a 'one size fits all' answer to a question like this. Neither the tire manufacturer or the the MoCo know how you're going to use your bike, how big you are, whether you're going to be riding double a lot or whether you're gonna strip it down or load it up or whether you're gonna ride it hell bent for leather or cruise around town on it.

They also don't know fer sure where it's going to be used. If it's in Alaska or if it's in S Florida, the 'factory' specs are the same. Now, don't you guys think there's a lttle difference between the two? I do because climate (ambient air temp) has a lot to do with how a tire is gonna perform.

I mean, kee-rist, even the roads are built differently in different regions. Tar content, are there polymers in the asphalt, are you on concrete a lot, et, etc, ad nauseam. Not to mention the condition of the roads. I've been on roads that just simply beat the living hell our of me. Even brand new roads. It's like they went out of their way to make them miserable.

Bottom line being, the Owners Manual and the tire sidewall information is just a guide. On a new bike that you're not familiar with, start with the recommended tire pressure and adjust it to suit your comfort and safety needs.

If you weigh 250lbs and you're gonna load it up with with 200lbs of woman and fifty pounds of gear, you might wanna see what the tire sidewall sez about maximum load and inflation PSI. Thereby giving you an excuse to dump the woman at the next rest area.

Common sense folks. Common sense.

 

You too are 100% correct. Not all tire gages are alike! I keep using the gage I have as I now know it's about a 2 lb difference from the stealer that changed out my front while on a road trip. He says mine was 2 lbs lower. So, I'm somewhere between 36-38 up front and 38-40 out back, which is good enough for me. I can feel the difference with these pressures. Using my gage, I continue to use the 38 and 40 psi.

Good insight on your part!

 

38 front and 40 rear

 

Well let's throw this in the mix. Had pulled the rear tire and brought it in to my indy cuz of a slow leak. Replaced the tube. While in there an old friend and longtime Harley owner started yakkin about tire pressures and wear, as I explained why I replaced the tire in the first place.

He moved his up to 42-44 on the rear and 38 up front. Now he says his tires are lasting much longer and the ride is just fine. The indy said he does the same. Thought I might give it a try. Ride seems good and handling is tight.

I guess time will tell...........Agree with the difference in guages, especially the old cheap ones. I try to spend a little more on those in hopes they're actually more accurate.