Tire Pressure

[Strictly Street]

OK, ORDN peeps, here's a question for you.

 

What tire pressure do you keep on what type of bike? Winter? Summer?

Shops seem to use higher pressures. IP likes 35/lbs it would seem from previous trips to them.

So what do you use for your track bike or street bike?

Or are they the same?

[Tonik]

Street bike at or near the max pressure on the sidewall of the tire. The engineers for the tire companies are WAY smarter than the mechanic at the shop or any of the peeps on OR. And I only use helium, It just just floats through the corners.

[Bubba]

SS:  That question is about as easy to answer as "What's the best oil?"  Tire pressure depends on SO MANY things:  type of bike, type of tire (radial vs bias-ply, tube vs tubeless), weight of bike, weight of bike+rider+passenger+luggage, type of riding, overall average speed, anticipated top speed, air and/or road temperature, and even how you personally want to balance tire grip with tire longevity.  From my experience, there are some general "rules of thumb":

 

1) You really can't go too badly wrong sticking with the manufacturer's recommendation in the owners manual. (This assumes you haven't dramatically changed the type of tire that came on the bike as OEM.)

 

2) Generally, the heavier the bike and it's load (rider+pass+luggage) the higher the pressure.

 

3) Lower pressure will usually result in a shorter tire life.

 

4) For extended extreme speeds (i.e., >120-130 MPH) you should bump the recommended pressures up several pounds.  NOTE:  THIS DOES NOT EQUATE TO BETTER HANDLING!!

 

5) For track days, most run lower pressures than typical street pressure for increased grip.

 

6) For colder air/pavement temps, slightly lower pressures give better grip.

 

All of this shouldn't be taken as gospel, but is a short summary of what I've experienced over about 50 years of riding both street and dirt.  Never exceed the maximum pressure listed on the tire sidewall, and don't exceed the GVWR of your motorcycle.  When I say 'lower' or higher' I'm generally talking just a few pounds of inflation.  For instance, I typically keep my tires inflated to about 34/36 F/R (Suzuki DL650, ~525#, DS radial tires) for normal commuting.  If I plan on running the backwoods aggressively, I lower the pressure to 32/34.  In winter weather, this might be as low 30/32.  When I load up for a trip, whether it's on backroads or expressway, I air up to 36/38+.  And I never have any tire problems on the Strom with extreme 130+MPH speeds....

 

BTW, I ride the poor little thing pretty hard and typically only get 5000-7000 miles out of a set of tires.  My front usually lasts a little longer than the rear, but I pitch it when it gets triangulated, even if it still has some tread left.

Edited November 20, 2015 by Bubba

[Bubba]

Street bike at or near the max pressure on the sidewall of the tire. The engineers for the tire companies are WAY smarter than the mechanic at the shop or any of the peeps on OR. And I only use helium, It just just floats through the corners.

 

Jim:  This prolly works for you, but that would be higher than is typically spec'd by the manufacturer.  Max sidewall inflation pressure might give you greater tire longevity but prolly isn't ideal for everyday riding with respect to grip.  Of course, it depends on the type of bike, blah, blah, blah, but my guy tells me this would only be the case where the tire size and tire load rating were very close to the bike+rider weight, i.e., heavy cruiser with slightly undersize tires.  YMMV....

[Tonik]

Jim:  This prolly works for you, but that would be higher than is typically spec'd by the manufacturer.  Max sidewall inflation pressure might give you greater tire longevity but prolly isn't ideal for everyday riding with respect to grip.  Of course, it depends on the type of bike, blah, blah, blah, but my guy tells me this would only be the case where the tire size and tire load rating were very close to the bike+rider weight, i.e., heavy cruiser with slightly undersize tires.  YMMV....

 

Kawasaki suggests 26 lbs for my front tire. It is a nightmare at that pressure on a 900 lb bike. Ma Kaw has always under inflated tires, so yea my advice is from my experience.  There are always exceptions to rules.

[MidgetTodd]

Track 22R 32F Dunlop GP-A

Street 28R 32F Dunlop Q3

Per Dunlop trackside support.

Also sidewall max pressure is just that, max. It's not the mfg suggested pressure.

[Bubba]

Jim:  26???  Yowzah.  That seems way low for a big cruiser.  That must be recommended inflation for parade drills....

[TimTheAzn]

Track 22R 32F Dunlop GP-A

Street 28R 32F Dunlop Q3

Per Dunlop trackside support.

Also sidewall max pressure is just that, max. It's not the mfg suggested pressure.

 

28R on a Q3 on the street? Dang haha. I am usually 32F 35R cold temps.

[Tonik]

Jim:  26???  Yowzah.  That seems way low for a big cruiser.  That must be recommended inflation for parade drills....

 

Not even parades, I wore out my front tire before I even got out of the dealer's lot.

[TwiztedRabbit]

Track : Michelin cup 22r 30 front

Track : pirelli sc 26.5r 32 front

Street: pirelli sp 28r 32 front

Street: Michelin supersport 26r 30f

My riding Conditions are from 50 to 100 degrees pressures vary 1-2psi based on temps.

[MidgetTodd]

28R on a Q3 on the street? Dang haha. I am usually 32F 35R cold temps.

Straight from Dunlop. And 35 is pretty high for a sport rear unless you're commuting or carrying a fat girl. I do neither.

[2talltim]

42f/42r that's what the bike calls for that's the max side wall psi and if I run any less I'll get less than half the milage. Never had a problem with grip either.

[Connie14]

^ what he said. Though I don't top off my air until the TPMS reads 40psi cold.

[Tonik]

Clearly the Kaw riders in this thread know WTF they are talking about.

[ReconRat]

Basically correct.

 

Here are some observations from an engineer type guy that has done work with tires and things that pressurize.

 

1. The absolute minimum tire pressure is 26psi per DOT tire standards, for road tires. Going lower will degrade the tire.

2. Bikes should show two tire pressure setups. One for single rider and one for with a passenger. Some do not.

3. A rough guess for single rider is 25% lower than max on the rear tire only, compared to max pressures for two.

4. If you see cracks in the sips of your tire tread when your tire really isn't that old, you probably ran pressures too low.

5. DOT standards recommend adding 3 psi per tire for sustained speeds over 70.

6. Actual optimal pressures are found by rigging and loading the bike and weighing vehicle road weight below both tires (with rider geared up), and selecting pressures from the DOT tire manual. (I have the manuals, but a lot of the newer ultra low profile tires aren't listed.)

7. The max rating of the tire is not the pressures you should use. The vehicle weight determines the pressure. If the vehicle wheel weight is higher than the tire rating, it's the wrong tire. If the recommended pressure goes lower than 26psi, it's the wrong tire.

 

8. I've seen really low pressures recommended by the manufacturer for front tires on cars and motorcycles. It's my opinion that reflects on an error in the design of the front suspension or vehicle, and the engineers/designers are trying to compensate. Not cool.

 

9. I have no advice about nitrogen, other than what I learned for aircraft. It's meant to keep tires from over expanding at high altitudes and jamming in the aircraft wheel well. Bad when you can't lower the landing gear. Guess I'll look some of it up.

 

edit: my 919s are 34F 36R factory. I typically run 30-32F 28-30R solo. Stock tire sizes.

Edited November 20, 2015 by ReconRat

[Bubba]

Not even parades, I wore out my front tire before I even got out of the dealer's lot.

 

Damn!  HELL'A big parking lot.  LOL

[zx3vfr]

Whatever the sticker on the swing arm says

[swingset]

I go with the OEM recommendations, air up if two-up or loaded for a trip.

 

If I'm running extended gravel or really loose conditions, I air down 10lbs.