T31 is dead, long live the T32.

[beemerphile]

The general rule is ... for every 10 degrees in air temperature change will result in one pound of pressure change. If the temp goes up, tire pressure will increase, and vice versa.

The general rule is PV = nRT > P = nRT/V
For a given tire with a given molar quantity of air and ignoring small volume changes n, R, and V are constant
therefore P/T = nR/V and is constant, so if the temperature goes up (or down) by 10%, then the pressure likewise changes 10%
The kicker is that the ratio is given in absolute temperatures and pressures and we are used to relative measures.
For example, a tire with a starting temperature of 80 degrees F = 540 degrees Rankine
If it had a starting pressure of 32 psi it would be ~46.7 psi absolute.
A 10% increase in pressure would be 4.67 psi
A corresponding 10% change in temperature would be 54 degrees
This would equate to 11.5 degrees for a 1 psi change.
Round numbers > 10 degrees per psi

 

[Shawn K]

The moral of the story is: Get in the habit of checking your tire pressure before every ride. It only takes a few moments.

 

[Uncle Phil]

The moral of the story is: Get in the habit of checking your tire pressure before every ride. It only takes a few moments.

Or get a TPMS system for those of us that are lazy ....

 

[Shawn K]

Or get a TPMS system for those of us that are lazy ....

I lump that in the "check your tires" category.

The point is to know what the pressure is, not assume.

 

[caldercay]

It's Thur now.

Tue morning I checked and filled up the tires on the wife's SUV, as she was off to a horse show an hour later.

Overnight (Tue night /Wed morn), the temps plunged about 25°F.

Wed morning (~8am), i drove her SUV to the VA clinic for a flu shot ... on the way, I clicked to the TPMS screen ... each tire dropped three PSI ... needless to say, when I got home, there i am, airing up her tires again a day later.

And now, it's a "day later" again, and the overnight temps dropped even further, so I'll need to check them yet again...

 

[beemerphile]

cue @CYYJ for the story on tire pressure variations when flying into winter Alaska...

 

[Larry Fine]

Without a TPMS, every check drops the pressure a bit, assuring the need to top off regularly.

 

[Larry Fine]

I just ordered a pair of T32s in stock sizes. F: $142.99, R: $168.99, free shipping.

With the rebate card, the net will be $311.98 - $50 = $261.98. Not too shabby!

Bridgestone Battlax Several Models..... Hypersport S22 Tires Cheap 120/160 set $178 rebate form included | Discounts / Group Buys

I know many of us own multiple bikes. Might save a few of you some cash if they have the size(s) combo that works for you. https://motomummy.com/categories/sport/tires/bridgestone.html...

www.st-owners.com

 

[Ralf_CT]

I'm still running a pair of Battlax BT023s, they seem to last quite well. Just over 2k kms on the rear, not sure when the previous owner fitted the front.

 

[Al Gully]

Well these sound like a good tire for the "Wet" err west coast of North America.
Gotta get me a set of these soon before they are sold out.

 

[Larry Fine]

Well, a pair of T32s just showed up on my front porch.

 

[klaproth]

Just ordered a few rear T32 tires for various bikes in the garage, best prices were at Chapmoto.com, about 10% off anyone else.

 

[dduelin]

I'm still running a pair of Battlax BT023s, they seem to last quite well. Just over 2k kms on the rear, not sure when the previous owner fitted the front.

BT023s are still a current tire according to Bridgestone's web site but not in the ST1300 sizes. What is the manufacturing date code on those 023s? I don't like to run tires more than 3 years old myself.

How To Read Motorcycle Tires | JPCycles.com

How To Read Motorcycle Tires

www.jpcycles.com

 

[Kevcules]

BT023s are still a current tire according to Bridgestone's web site but not in the ST1300 sizes. What is the manufacturing date code on those 023s? I don't like to run tires more than 3 years old myself.

How To Read Motorcycle Tires | JPCycles.com

How To Read Motorcycle Tires

www.jpcycles.com

That's something most people aren't aware of, or care about when buying tires IMO. I always check to make sure the tire is less than 2 yrs old at the most. The older tires tend to come on sale, so watch out.

 

[Jjonahjamison]

Well, a pair of T32s just showed up on my front porch.

Larry, if you are putting the T32s on yourself, please let us know how difficult they are to install. Thanks.

 

[Larry Fine]

Larry, if you are putting the T32s on yourself, please let us know how difficult they are to install. Thanks.

I considered it, but I'm leaning toward putting them on the bike instead.

No, I'm too lazy. I can work for less than an hour (self-employed electrical contractor) and pay to have them put on and balanced at my local Honda dealer. Ride in, hand them the tires and my little jar of Loctite, wait a while, and ride away.

 

[Ralf_CT]

BT023s are still a current tire according to Bridgestone's web site but not in the ST1300 sizes.

They list the BATTLAX BT-023 SPORT TOURING 120/70ZR18 M/C (59W) TL (Front) and BATTLAX BT-023 SPORT TOURING 170/60ZR17 M/C (72W) TL (Rear), these sizes seem correct according to the Owners Manual?

 

[dduelin]

They list the BATTLAX BT-023 SPORT TOURING 120/70ZR18 M/C (59W) TL (Front) and BATTLAX BT-023 SPORT TOURING 170/60ZR17 M/C (72W) TL (Rear), these sizes seem correct according to the Owners Manual?

Yes, those are the correct sizes. I guess I was looking yesterday at the OE section of the North America web site.

Still, the 023 is a tire three generations old now and I’d be watchful of old stock tires. Check the manufacture date on the sidewalls.

 

[naedlaen]

Someone mentioned riding style as affecting tire wear, so I will mention that the materials used for the road also affect tire wear. Crushed stone asphalt will wear tires faster than rounded river stone asphalt. Portland cement roads may not have as much difference between stone surfaces. I am sure that there is a difference between asphalt and portland cement concrete. I do know that crushed gravel roads are harder on tires than river run gravel. Crushed granite will wear tires differently than crushed limestone.

So the only way to determine which tire will last longest for you is to try lots of different tires as your roads and riding style probably make your situation unique to you.

Neal

 

[Johnny Rocco]

The ST13 I bought last fall came with a set of T30's that are reasonably 'fresh'. They should be done by the time the first tour happens in June. I ordered a set of Road 5's, based on what I was reading here and there. I'm typically very good with tire pressures and typically get even tire wear. As far as mileage goes, my tires are typically cooked under 10k (kilometres). I'm interested in seeing what the Road 5's will do. Because tires were a little scarce last year (Covid), I've ordered a pair of T32's and look forward to rating them. I've run 30's and 32's on my ST11 with good results.