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Recommended tire pressure for 2009 f650 GS equipped w Tourrance tires

hoss01

hoss
Fellow Riders,

Seems there is lots of wiggle room on the proper tire pressures for the metzler, Tourrance,
140/80 R 17/19 tires.
I ride one up, basically on paved or gravel roads, and do some long distance riding carrying luggage etc.
The local dealership ( Grand Rapids,Mi. ) had a workshop recently and the Metzler rep. talked at length
about how critical correct tire pressure is to safety, handling, and tire longevity.
I thought his reccomendations were 42 rear...40 front. These are not the number shown on the sidewalls.
Would appreciate your input.
Thank you in advance
Hoss
 
Fellow Riders,

Seems there is lots of wiggle room on the proper tire pressures for the metzler, Tourrance,
140/80 R 17/19 tires.
I ride one up, basically on paved or gravel roads, and do some long distance riding carrying luggage etc.
The local dealership ( Grand Rapids,Mi. ) had a workshop recently and the Metzler rep. talked at length
about how critical correct tire pressure is to safety, handling, and tire longevity.
I thought his reccomendations were 42 rear...40 front. These are not the number shown on the sidewalls.
Would appreciate your input.
Thank you in advance
Hoss

There is always wiggle room to suit certain circumstances. Sidewall number represent a maximum load number at a specific psi. I don't think any tire states otherwise although I am not certain of that. There are so many variables I don't think it's possible to state with certainty specific psi for every time you get on the bike. You tend to run at happy mediums to suit most circumstances. I would recommend however if you are running maximum load, not difficult to achieve by the way, that you stick with the sidewall-stated specifics. Unless you know more than the tire engineers I would stick with their numbers.
 
Fellow Riders,

Seems there is lots of wiggle room on the proper tire pressures for the metzler, Tourrance,
140/80 R 17/19 tires.
I ride one up, basically on paved or gravel roads, and do some long distance riding carrying luggage etc.
The local dealership ( Grand Rapids,Mi. ) had a workshop recently and the Metzler rep. talked at length
about how critical correct tire pressure is to safety, handling, and tire longevity.
I thought his reccomendations were 42 rear...40 front. These are not the number shown on the sidewalls.
Would appreciate your input.
Thank you in advance
Hoss

If I remember right Tourance is a recommended tire for this bike... and in that case, why not go with the recommendations printed under the seat from BMW?

Running that high of pressure on the front would decrease your stoping ability and cornering grip....

flame away...
 
One doesn't go with the "recommendations printed under the seat" because
1) BMW does not design tires
2) BMW does not manufacture tires
3) That sticker is for one certain brand & model of tire with some "standard" rider under some "standard" riding conditions (including road type, speed, and load, such as rider's weight, maybe passenger's weight, saddlebags empty or loaded, etc.)

Even a rep may not have the numbers memorized for all his various models.

Go with what it says on the sidewall - start at about 10% or 15% lower (when dead cold and with a known-accurate gauge), and play from that baseline. Also review the tire manufacturer's site for their recommendations, keeping in mind that they don't know you either, and the site may not have been updated for a while...
 
I sat in on the same presentation at BMW of Grand Rapids and what I remember him saying was that you should always run Max pressure that is listed on the side of the tire. In most cases he said that would be 42psi. I have always gone by the recommended pressure in the owners manual and realized that I have the wear patterns that he said indicates low air pressure. I have an old set of Battlewings off of my wife's F650gs that he could use to demo low air pressure wear patterns. These tires list 42psi as max pressure and we ran them at 32psi front and 36psi rear so according to him they were grossly under inflated. After listening to his presentation I am going with his recommendation.
 
While I agree there is really a lot of latitude in acceptable tire pressure as there are tires available.

FWIW I don't obsess on pressure....when I do check it I use 32 front 36 rear cold.

I certainly would not start cold at the max pressure printed on the tires.....but I suspect that too has such a wide design margin...that too does not really matter.

tubeless tire are a tough lot
 
I sat in on the same presentation at BMW of Grand Rapids and what I remember him saying was that you should always run Max pressure that is listed on the side of the tire. In most cases he said that would be 42psi. I have always gone by the recommended pressure in the owners manual and realized that I have the wear patterns that he said indicates low air pressure. I have an old set of Battlewings off of my wife's F650gs that he could use to demo low air pressure wear patterns. These tires list 42psi as max pressure and we ran them at 32psi front and 36psi rear so according to him they were grossly under inflated. After listening to his presentation I am going with his recommendation.

That is nonsense. That number embossed on the tire is the maximum safe pressure at 20 degrees centigrade based on the construction of the tire and its load rating - put there as required by Federal regulations.

If you really want to do it right set the cold pressure:

For bias ply tires - so that the difference cold to hot is a 10% pressure rise.

For radial tires - so that the difference cold to hot is a rise of 6psi to 8 psi.

My naked K75 and a K1100LT both take the same front tire. Voni's little F800S and my R1150 both take the same front tire. If anybody actually believes that since the maximum cold pressure on the sidewall is the same on the tires the inflation should be the same, even though there is a 100+ pound difference in weight of the bikes, they are simply wrong.
 
WELL PUT, SIR! :thumb

"I read it on the Internet, so has to be true." :banghead
"My dealer said so, so it has to be true." :banghead
"I don't want to risk voiding the warranty." :banghead

We were born with brains, now let's use our minds!
 
That is nonsense. That number embossed on the tire is the maximum safe pressure at 20 degrees centigrade based on the construction of the tire and its load rating - put there as required by Federal regulations.

If you really want to do it right set the cold pressure:

For bias ply tires - so that the difference cold to hot is a 10% pressure rise.

For radial tires - so that the difference cold to hot is a rise of 6psi to 8 psi.

My naked K75 and a K1100LT both take the same front tire. Voni's little F800S and my R1150 both take the same front tire. If anybody actually believes that since the maximum cold pressure on the sidewall is the same on the tires the inflation should be the same, even though there is a 100+ pound difference in weight of the bikes, they are simply wrong.

Paul you confused me. My thinking was that radial tires ran cooler than bias ply tires. 10% of say 40 psi would be 4 lb. Would it not, take more heat to raise the 6-8 psi. I go for about 3 to 4 psi raise on radial
tires.
So you need to run a lower pressure to create more heat for the radial tire. Correct.
 
Paul you confused me. My thinking was that radial tires ran cooler than bias ply tires. 10% of say 40 psi would be 4 lb. Would it not, take more heat to raise the 6-8 psi. I go for about 3 to 4 psi raise on radial
tires.
So you need to run a lower pressure to create more heat for the radial tire. Correct.

I got the 6 to 8 psi rise initially from a Metzeler rep, and it was agreed with later by a Michelin rep. I posed the question at first when I discovered there was no way I could hold the rear radial tire on my R1150 to a 10% rise unless I started with a cold pressure of about 48 psi on a tire marked for a max cold pressure of 42.

In the discussion I was told that the sidewall construction is the key difference, and that radial tires by design flex more and thus warm up more. I have had good results with the 6 to 8 psi rule of thumb on radials.

I have a Smartire tire pressure monitoring system on my R1150 that shows pressure, temperature correction, and internal tire temperature. It is pretty easy to see what is going on.
 
One doesn't go with the "recommendations printed under the seat" because
1) BMW does not design tires
2) BMW does not manufacture tires
3) That sticker is for one certain brand & model of tire with some "standard" rider under some "standard" riding conditions (including road type, speed, and load, such as rider's weight, maybe passenger's weight, saddlebags empty or loaded, etc.)

Nonsense.

BMW designs motorcycle that run on tires and BMW designs the handling and the load carrying capability and thoroughly tests both.

You'll look long and hard for actual pressure recommendations from tire manufacturers for each and every possible motorcycle--or even yours--but BMW provides its recommendations and they are they best you'll get. My owners manual gives me the BMW site URL to find the list of tires currently applicable to my bike and for which my underseat sticker recommendations are compatible. It's not as if there's a massive difference in tires, i.e. brands and models, that are the proper size. The underseat sticker gives me two or three scenarios as to loads.

Just another post that BMW is clueless and like every one previously posted, it's complete nonsense.
 
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