4 PSI question for our experts

[seaweed]

Lately my rydes have been 20 to 50 miles with temperatures of mid to upper 60's. I set my pressures at a tad under 20 PSI for front and under 28 PSI for rear tire. Yes, unfortunately I have Kenda tires.

I will be taking several 300 plus mile rydes with temperatures of low 50* F. Should I set the pressures at 18 and 26 PSI or even lower prior to the start of the ryde?

[Navydad]

Lately my rydes have been 20 to 50 miles with temperatures of mid to upper 60's. I set my pressures at a tad under 20 PSI for front and under 28 PSI for rear tire. Yes, unfortunately I have Kenda tires.

I will be taking several 300 plus mile rydes with temperatures of low 50* F. Should I set the pressures at 18 and 26 PSI or even lower prior to the start of the ryde?

Probably get several thoughts on this, but if it were my Spyder with the Kenda tires I would put them at the manufacturers recommended PSI and leave them alone. Air temp is not going to affect them enough to be an issue.

[spyderdave]

I read in some auto mag, years ago, that tire pressure changes (up or down) 1 degree for every corresponding 10 degrees in air temperature, I wouldn't be to concerned regarding the situation you describe.

[jjc54]

Tires should be checked cold but what temperature is considered cold? Is there any correction that needs to be made if checking at 40F or 85F?

[BajaRon]

An interesting and valid question. I am curious as to how 'Seaweed' and 'Colorado' go together though.

Some consideration needs to be made for weight (overall loading), and the type of riding you are doing. That being said, I would avoid overthinking this.

If you are doing mostly highway riding, straight ahead and not too may tight curves. A lower pressure can be used. This gives the tire more compliance and a nicer ride. If you are doing mountain riding with lots of curves, a few pounds more will help keep the sidewall from rolling under (especially when riding Kenda's) and give you better handling.

Air in tires does get hotter than the ambient temperature, especially when the pavement is blazing hot. And as the tire complies with the road surface, flexing of the tire and friction generates additional heat. Hot air takes up more space than colder air so this translates into higher PSI within the tire. But the heat also softens the tire compounds and the increased PSI tends to compensate as the sidewalls soften with the heat, etc.

It's always good to experiment with tire pressures to find your sweet spot. I recommend a digital pressure gauge to increase accuracy. And a 2 PSI or greater change as lesser amounts won't make enough difference to tell if you're going in the right direction.

[BLUEKNIGHT911]

An interesting and valid question. I am curious as to how 'Seaweed' and 'Colorado' go together though.

Some consideration needs to be made for weight (overall loading), and the type of riding you are doing. That being said, I would avoid overthinking this.

If you are doing mostly highway riding, straight ahead and not too may tight curves. A lower pressure can be used. This gives the tire more compliance and a nicer ride. If you are doing mountain riding with lots of curves, a few pounds more will help keep the sidewall from rolling under (especially when riding Kenda's) and give you better handling.

Air in tires does get hotter than the ambient temperature, especially when the pavement is blazing hot. And as the tire complies with the road surface, flexing of the tire and friction generates additional heat. Hot air takes up more space than colder air so this translates into higher PSI within the tire. But the heat also softens the tire compounds and the increased PSI tends to compensate as the sidewalls soften with the heat, etc.

It's always good to experiment with tire pressures to find your sweet spot. I recommend a digital pressure gauge to increase accuracy. And a 2 PSI or greater change as lesser amounts won't make enough difference to tell if you're going in the right direction.

" I would avoid over thinking this " .... X's 10 ..... the difference between Perfect and Normal is so small it might as well not exist..... Mike

[baxter]

As above , don't make it hard. I check mine before leaving on multi day trips to factory settings and have ridden through hot, cold, desert, mountain conditions wet/dry on same trip with no issues in handling or ride. Yah, running factory tires and suspension.

[canamjhb]

When I toured extensively during the summer months, usually 4-6 weeks at a time, I was obsessed with tire PSI. My usual trips included beginning at 1,500 foot elevation with temperatures above 100F. I then would spend a couple weeks in much cooler higher elevations (5,000-8,000+). Then I would spend a couple weeks cruising cool coastal areas. I found the PSI would change by a couple pounds based upon elevation and ambient temperatures. My tires were visually check each day and PSI checked/adjusted every 4-5 days. Most of the time the tires didn't need adjustments..... But I just needed to satisfy my tire obsession. Just part of the joy of extended touring.

But, by far, the biggest factor in satisfying my obsession was to send my OEM Kenda's where I thought they belonged...... To tire recycle heaven. Biggest piece of mind for me was knowing I had good quality tires under me. Having said that, I would run the Kenda's at the recommended PSI. They need all the help they can get. Good luck..... Jim

[seaweed]

Thanks for all the opinions and info.

Ron, the handle "Seaweed" was obtained many years ago while in the service. When I joined this Forum, I used that handle. Strange, you are the first to question the relation of Seaweed and Colorado.

I guess that I was over thinking the PSI issue. But I will keep an eye on it.

[RayBJ]

Tires should be checked cold but what temperature is considered cold? Is there any correction that needs to be made if checking at 40F or 85F?

Outside temperature is not relevant when talking about 'checking when cold'. Tires warm up as they are ridden so 'Cold checking' means the PSI before the tires are run and brought up to operating temperature after several miles.

[Peter Aawen]

Lately my rydes have been 20 to 50 miles with temperatures of mid to upper 60's. I set my pressures at a tad under 20 PSI for front and under 28 PSI for rear tire. Yes, unfortunately I have Kenda tires.

I will be taking several 300 plus mile rydes with temperatures of low 50* F. Should I set the pressures at 18 and 26 PSI or even lower prior to the start of the ryde?

I wouldn't be using anything but maybe +/- 2psi from the OEM recommended pressure on Kendas!!

And while the 4psi rule (of thumb) is a good place to start for any other tire, there's also a well documented recommendation to INCREASE your 'usual running' pressures (established/supported via the 4psi rule) by about 2psi whenever you are planning longer, faster, &/or more heavily laden runs to avoid or at least minimise any OVER-HEATING caused thru under-inflation! Your tire pressures are MEANT to go up by about 4psi during a ride - any less increase means you've over-inflated them; any more increase means you've under-inflated them! But unless you are on a track and chasing the last bees-whisker of performance &/or tire life, you really shouldn't need to worry too much if they're within a psi or 2 either way...

So what everyone else has already said is up there ^^ is spot on, don't overthink this;

• if you're not running Kendas, you really SHOULD NOT REDUCE PRESSURES for a longer, heavier than usual, &/or faster ride from your 4psi established/supported pressures; and
• if your Spyder is still fitted with Kendas, then DEFINITELY NO, DO NOT REDUCE YOUR PRESSURES FOR A LONGER, HEAVIER THAN USUAL, &/or FASTER RIDE than your usual ride.

For those sorta rides, if anything, you'd do the exact opposite to what you've proposed up there, and (qualified a little depending on how cold it might get and your need for increased wet road traction, but not snow & ice! ) you'd generally expect to INCREASE your tire pressures by maybe as much as 2psi, but given the Kendas well recognised tendency to wear (the rears especially ) as if they're over-inflated anyway (altho they probably aren't, it's more likely just the centre of the tread been thrown out so that's the only bit that ever touches the road cos they are so lightly made, &/or the tire's too wide for the rim! ) just use the OEM recommended pressures in your Kendas or you risk even more issues than usual!!

[BajaRon]

Thanks for all the opinions and info.

Ron, the handle "Seaweed" was obtained many years ago while in the service. When I joined this Forum, I used that handle. Strange, you are the first to question the relation of Seaweed and Colorado.

I guess that I was over thinking the PSI issue. But I will keep an eye on it.

We all overthink some things and under think others. It just varies by person.

Thanks for the seaweed explanation. I guess I notice because I get a lot of 'How does BajaRon and east Tennessee come together?'. That's why seaweed and Colorado stood out to me.

[Br549rick]

seaweed just seems to roll off the lips easier than secord, seawright and such....not unique only to your corner of USAF.. you might guess how i know....

[Br549rick]

generally cold tire refers to a tire that has not been driven any significant distance therefore not generating any pressure increse from usage

[BajaRon]

seaweed just seems to roll off the lips easier than secord, seawright and such....not unique only to your corner of USAF.. you might guess how i know....

I did my time in San Diego as a Navy Brat. My dad was on the Midway, which is now a museum in San Diego. It was really a treat touring that ship with my dad. Seaweed! Yep! Been there, done that... Spent a good deal of time in the Pacific, fishing, surfing, scuba diving. Don't get much opportunity since I moved here to East Tennessee!

[vito1943]

I hate the hassle of adding air to the rear tire, so at the start of the riding season I put new batteries in my TPMS tire caps and then bring the psi to 2 or 3 above the recommended 28. And for the front tires I also put 2 above the recommended 18. Last year this allowed me to go the entire riding season, until mid November, without having to add air. By then my TPMS was reading 26 rear and 17 front, which I consider very acceptable. FWIW, I don't notice any problem with the ride when the pressures are at my higher than recommended amounts. I have almost 12,000 miles on the RT and still have the original Kendas.

[Peteoz]

I hate the hassle of adding air to the rear tire, so at the start of the riding season I put new batteries in my TPMS tire caps and then bring the psi to 2 or 3 above the recommended 28. And for the front tires I also put 2 above the recommended 18. Last year this allowed me to go the entire riding season, until mid November, without having to add air. By then my TPMS was reading 26 rear and 17 front, which I consider very acceptable. FWIW, I don't notice any problem with the ride when the pressures are at my higher than recommended amounts. I have almost 12,000 miles on the RT and still have the original Kendas.

Yes, I do pretty much the same, Vito…..1 - 2 psi over. That system works well for me, too.

Pete