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Discussion Starter · #1 ·
Hello everyone,

Still being new to the bike particulars here so I spent some time looking around on the site to learn what I can. I came across a thread on tires discussing the tire and the pressures you guys are using.

I notice that some run pretty high pressures. Higher than what the factory says to run them, however I know that the factory tire and what you put on later are not the same.

Part of what I was taught when I was taught to ride and be responsible for, was to pay attention to the bike you ride was, pay attention to your tire pressures. I have Metzler Marathon's on the bike. 260 series on the rear.

I have the pressure at factory recommended numbers.

How do you guys determine your pressures and why? Your body weight? Your roads? ???. I definitely want to get as many miles as I can on a tire and I also like the bike to handle as crisply as I can.

Or do you know by the size and brand of the tire?

Should I run something different than factory specified pressures?
 

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:welcome: to the forum . Always go with the factory spec. air pressure that the tire says. If that tire is recomended for the bike . Where you get into different pressures is running an aftermarket tire that is not recomended for the rim size on the bike. Like running a 280 rear on a stock rim. At stock pressure the tire rubs,if you put 10psi more it won`t rub.
Hope this helps, for all around riding your spec air psi. is what to run on the metzger tire.
 

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Hey Blondie, good question.

I was always told by motorcycle gurus that the stock tire pressures were determined by the engineers of the motorcycle, and that no matter what tires you are running, you should run the same psi as the label says on the bike to maintain the bikes feel/riding characteristics.


P.S. slow your roll! You are catching up to me in post count and its been what!? Not even two weeks!!!? :D:joke:
;)
 

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I believe the manufacture settings are 36 front, 42 rear.

I have been runing 40 front, 42 rear for 37k miles. I get 14-15K out of my front tire before it is cupped bad enough to replace. I get 10-11k out of my rear. These are the Dunlop E3's but that psi works great for me.
 

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Discussion Starter · #6 ·
Hey Blondie, good question.

P.S. slow your roll! You are catching up to me in post count and its been what!? Not even two weeks!!!? :D:joke:
;)
Hey the bike is new I have a lot to learn right now. I'll slow down soon.....til the Mods start........*sigh*
 

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Discussion Starter · #7 ·
I believe the manufacture settings are 36 front, 42 rear.

I have been runing 40 front, 42 rear for 37k miles. I get 14-15K out of my front tire before it is cupped bad enough to replace. I get 10-11k out of my rear. These are the Dunlop E3's but that psi works great for me.
Are these your factory tires? Mine already has Metzler's on it and yes these are the pressures I am at now 36/42. But the thread on tires I see some running like 46. My tire is larger than factory in width, as are the tires mentioned in the thread.
 

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Discussion Starter · #8 ·
:welcome: to the forum . Always go with the factory spec. air pressure that the tire says. If that tire is recomended for the bike . Where you get into different pressures is running an aftermarket tire that is not recomended for the rim size on the bike. Like running a 280 rear on a stock rim. At stock pressure the tire rubs,if you put 10psi more it won`t rub.
Hope this helps, for all around riding your spec air psi. is what to run on the metzger tire.
TY revvin. If I understand your point, only the really wide tires need to have pressure made higher to clear the rub part. Otherwise I'm good.
 
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I run 34/38. I like to turn and burn, and it helps me heat the tires up faster so they stick, also gives a little better contact patch. I have not seen any abnormal wear.

For reference, I run 32/36 on my sportbike.
 

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Are these your factory tires? Mine already has Metzler's on it and yes these are the pressures I am at now 36/42. But the thread on tires I see some running like 46. My tire is larger than factory in width, as are the tires mentioned in the thread.
No, Dunlop E3's. The back is a 250, but in reality a tad wider or about the same as your 260. Stock tires are garbage and I pulled them off the bike with 1k miles on it.

I would never run 46 in my tire. I like the rear at 42, and the front at 40. I check the tires about every 2 weeks and they tend to drop a few pounds. When I do that the rear is around 40 and the front drops to 36-38...well within spec.
 
G

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No, Dunlop E3's. The back is a 250, but in reality a tad wider or about the same as your 260. Stock tires are garbage and I pulled them off the bike with 1k miles on it.

I would never run 46 in my tire. I like the rear at 42, and the front at 40. I check the tires about every 2 weeks and they tend to drop a few pounds. When I do that the rear is around 40 and the front drops to 36-38...well within spec.
Got a bad rim seal there broski? I never have that problem.
 

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Got a bad rim seal there broski? I never have that problem.
No, no bad rim seal. Very normal for the tires to lose air. Usually I notice it when the weather gets cooler. That is enough for your tire temperature to fluctuate 5 psi at some points. Usually in June, July and August, I rarely have to add. But when we get to fall, days are 75 and nights are 45....you will see that.
 

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What's on the tire

There will be varying opinions on this but I always run the pressure stated on the side of the tire.

The factory spec was for the factory tires. And, if you run those tires, that's the spec you should use. However, any time that you change to something different, you should follow the pressure on the side of the tire.

For example, a Dunlop tire has a pretty stiff carcass compared to an Avon Venom X. The Dunlop recommends 40 psi and the Avon recommends 50 psi (these are examples for a 150-90/15). Those are the pressures that the manufacturer has determined are needed to get the full load rating out of each tire.

But, if you run the Avon at 40 psi instead of 50, the tire carcass will flex more. Handling may suffer and the tire will flex more as it rolls. More flex = more heat.

Just my opinion but I always follow whats molded into the side of the tire.
 

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There will be varying opinions on this but I always run the pressure stated on the side of the tire.

The factory spec was for the factory tires. And, if you run those tires, that's the spec you should use. However, any time that you change to something different, you should follow the pressure on the side of the tire.

For example, a Dunlop tire has a pretty stiff carcass compared to an Avon Venom X. The Dunlop recommends 40 psi and the Avon recommends 50 psi (these are examples for a 150-90/15). Those are the pressures that the manufacturer has determined are needed to get the full load rating out of each tire.

But, if you run the Avon at 40 psi instead of 50, the tire carcass will flex more. Handling may suffer and the tire will flex more as it rolls. More flex = more heat.

Just my opinion but I always follow whats molded into the side of the tire.
Very good point. :bigthumbsup:
 

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Discussion Starter · #16 ·
There will be varying opinions on this but I always run the pressure stated on the side of the tire.

The factory spec was for the factory tires. And, if you run those tires, that's the spec you should use. However, any time that you change to something different, you should follow the pressure on the side of the tire.

For example, a Dunlop tire has a pretty stiff carcass compared to an Avon Venom X. The Dunlop recommends 40 psi and the Avon recommends 50 psi (these are examples for a 150-90/15). Those are the pressures that the manufacturer has determined are needed to get the full load rating out of each tire.

But, if you run the Avon at 40 psi instead of 50, the tire carcass will flex more. Handling may suffer and the tire will flex more as it rolls. More flex = more heat.

Just my opinion but I always follow whats molded into the side of the tire.
And I don't wish to add to any controversy here, however; I need to offer a point that might do so.

I'll make this short.

I learned a lesson from a 2006 Ford Explorer I owned. It had 18" rims, it was a special Edition Eddie Bauer. At that job I drove about 60K a year for business. I kept the air in my tires at what was stated on the sidewall of the tire all that because my previous Explorer was one of those Firestone Blow-Out models. They blamed it on being under-inflated and left us stuck with the results of that (mine blew before the recall started), so I was pretty sensitive to tire pressures.

That sidewall said PSI was 46 PSI, so I kept them at 46 PSI. At 11K miles my tires were shot due to over inflation. Had to buy new ones at $1200+ because nobody did 18" tires that early on in Ford's production year. Needless to say I was none to happy about it and when I complained, the service manager showed me that that Ford stated their pressure recommendations (in the manual as well as the door panel), and the tire company may not state the same, and the pressure on the tire was safe maximum pressure not recommended running pressure.

So my Metzler says 42 PSI on the side of the tire. That also agrees with the factory called for number. I have no problem staying there.

My question came about because I see people running tires of all sizes and makes and all different pressures, yet all on the same bike. The factory tire was not a Metzler, and Metzler I'm sure makes this tire that fits on all sorts of bikes, so I can't think that a one pressure fits all is the right way to think about it either. A Goldwing (yuk) is heavier than a 109 and I would think the pressures would be different between these 2 bikes as an example.

I was mainly trying to ask to educate myself as to why and how these different numbers get determined by the people posting up the numbers.

Also I was taught the importance of tire pressure on bikes being a lot more critical for ride quality and safety as well. So again I am not wanting to start a controversy and I think I get the rest about the technical parts. But would a rider at say 275 lbs, put the same pressure as a rider of say 125? Or should there by no difference because the tire figures all that out when they make them?

When I got the bike, the pressures were all lower than what was called for. 32/28 PSI.

My last bike, if I ran the pressure low, it made the tires wear out sooner. It was lighter than this bike by a lot.
 

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I agree...sorta

That sidewall said PSI was 46 PSI, so I kept them at 46 PSI. At 11K miles my tires were shot due to over inflation. Had to buy new ones at $1200+ because nobody did 18" tires that early on in Ford's production year. Needless to say I was none to happy about it and when I complained, the service manager showed me that that Ford stated their pressure recommendations (in the manual as well as the door panel), and the tire company may not state the same, and the pressure on the tire was safe maximum pressure not recommended running pressure.
There is validity to your issue with car tires. However it might not directly relate to a bike tire.

The example I gave (40 vs 50) for the diff brands of bike tire is significant. And, having changed both of those tires many times I know for a fact that the Dunlop carcass is much stiffer than the Avon. They are just made different. In order to get the full load rating out of the Avon it has to be run at 50. But, most of the other tire brands in the same size are run in the 40-42 psi range. But, at that pressure, they can carry the full load rating.

Since a bike tire is already crowned, running it at the full recommended pressure will not cause it to crown any more than designed. However, running it at less than recommended pressure will cause it to crown less. Of course, if you're not after the full load rating then that might be okay. But, if it flexes too much as the tire deforms each time it turns (running lower pressure) then the tire may heat up too much and it might wear quicker and/or handle badly (or maybe better). In a truly bad situation, it might cause the tire to come apart if it's run at a higher than design temperature too long.

If one wanted to calculate the needed pressure based on the weight of the bike/rider, you could simply weigh each end of the bike individually and see how that compares to the load rating of the tire and possibly adjust the pressure accordingly. If the actual weight was 10% less than the rating, the you might get by with 10% less pressure and all would be good. However, I think there's a limit. If the tire is rated at 1000 lbs at full pressure and there's only 600 lbs on it, I would be hesitant to reduce the pressure by 40% (that would be 16 psi less in a 40 psi tire). I think the tire would handle badly at that pressure and it would for sure run hot.

If you feel that the tire seems harsh at full pressure, I think that a 10% drop would be okay as long as you're pretty far below the load rating.

But, that is simply an opinion.
 

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You kind of have to take the info from the manufacturer, the info from the tire company, and then compare to what the riders say and have proven to work.

Almost everyone you ask will tell you 42/40 is what they run. Bikergranny and myself have run the same pressure. All the 109's I work on run the same psi as I always check tire pressure before giving it back. All of my friends who ride 9's, we all run the same. 3 bikes that are in my stable of 9's that I work on, all have Metz 260 rear, Metz stock size front, and are running 42/40. They all love the ride and have had no issues. Regardless of what the tire maker or manufacturer say, this is close the the manufacturers recommendations and I am comfortable with that. I have run the same pressure on both of our 9's with great results. That is roughly 55k miles.
 

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Discussion Starter · #19 ·
You kind of have to take the info from the manufacturer, the info from the tire company, and then compare to what the riders say and have proven to work.

Almost everyone you ask will tell you 42/40 is what they run. Bikergranny and myself have run the same pressure. All the 109's I work on run the same psi as I always check tire pressure before giving it back. All of my friends who ride 9's, we all run the same. 3 bikes that are in my stable of 9's that I work on, all have Metz 260 rear, Metz stock size front, and are running 42/40. They all love the ride and have had no issues. Regardless of what the tire maker or manufacturer say, this is close the the manufacturers recommendations and I am comfortable with that. I have run the same pressure on both of our 9's with great results. That is roughly 55k miles.
Thank you Big Poppa and tpres. This sort of gives me all the re-assurances I need to not really over think it.

I can go 40PSI up or down 3 and not worry to much about the negative effects.

I want to take the right care of her.
 
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