[Timothy G. Parrish]

Anyone religiously measure your tire pressure after you get done riding? I'm not sure why, but a few rides ago I measured my tire pressure after my ride. Pressure went up about 3 PSI per tire. Outside temperature probably had a little to do with it, but it had only increased about 10 degrees F. I did this again after a ride today. PSI went up about 2 lbs. So I'm setting my PSI at what I think is ideal, then I find myself letting air out midway during my ride. I'm probably going to start setting the PSI lower initially knowing this is happening. Just curious what others have found.

 

[Schulze]

Temperature change is something like 0.6psi/10 degrees F. If you pump up in the A/C at 70F then ride at 90F, plus the heating of the air in the tire due to the working of the rubber, a temporary 2 psi sounds about right.

 

[MSU Alum]

That's what I've seen. I don't worry about it.

 

[One Pivot]

You're stopping your ride to let out 2 psi?

That seems a bit extreme.

 

[Timothy G. Parrish]

You're stopping your ride to let out 2 psi?

That seems a bit extreme.

I typically set the pressure at home. Then during the ride, it feels harsh after a while. So I let air out. I can't tell you how much because I'm using the 'hand' gauge. But now that I know this, I'll start setting the pressure a few lbs less, knowing it'll increase during my ride.

I'm on a hardtail, so it's more noticeable than on my FS.

 

[Forest Rider]

Just don't ride the chunky stuff until you've had a chance to get the tire nice and warm.

 

[RustyIron]

And when the sun starts beating down on your tires, add a couple more psi. Maybe this is a good argument for white tires...

 

[cassieno]

You're stopping your ride to let out 2 psi?

That seems a bit extreme.

I know it's a bit extreme, but we have one extremely chattery trail near me, that I rode with 22 PSI, hands were feeling pretty beat and on my next lap I dropped to 20 PSI and everything felt a lot better. totally worth it to let out that two PSI. Which does seem a bit extreme I know....

Tire was a 2.5 DHF on a i30mm rim.

 

[agreenbike]

If you have ever pumped up your tires indoors, driven for some time (lets say even 30 minutes) with your bike on the back of your car/ on the roof/ in your truckbed then checked pressures at the trailhead you would notice that the pressure in your tires may go up 2-3 psi at least. I think the sun shining on your tires, warming them and causing the air inside to expand is responsible for such trends in tire pressure. Conversely pumping up tires in heated indoors then driving to a much colder riding area might cause your pressures to drop. Adjusting your pressure at the trailhead should solve all problems then as your tires should not change pressure anymore (I think) since your tires are warmed up.

You're stopping your ride to let out 2 psi?

That seems a bit extreme.

2 psi makes all the difference, IMO. I ride with my tires almost as low as they can go before they get squirmy, 1 psi too low and the casing wears very fast and cornering knobs lose their support but 1 psi over that ideal and the tire conforms less to the trail and pings off of rocks and stuff more. If your tires are squirmy, slow rolling, not grippy enough, etc. then changing what pressure you are running in your tires can make a big difference in your riding.

 

[edubfromktown]

Nope. I check tire pressures before rides only...

If bike handling feels sloppy or too bouncy during a ride, I adjust accordingly on the next ride.


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[Lone Rager]

I run low pressure and set it before every ride. I def notice the diff a few psi can make in harshness/traction but haven't checked it during a ride. I'll have to try that and see what I get.

Maybe makes SRAM's TyreWiz seem slightly less ridiculous.

 

[tfinator]

I have noticed this multiple times. Ilive near the ocean and if i wake up and get ready at 6-7am it is ~70°. By noon on the trail it out east it can hit 95°, sometimes more. It makes a difference.

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[keen]

Automotive tires are set "Cold". Pressures change w/ heat caused by friction. I don't think I ever had a baseline "home" pressure. I baselined after on trail experimentation.

 

[127.0.0.1]

nope


I set specific pressures pre-ride but after that

I just ride

 

[Chicane32]

Isn’t that why you start around 2 psi lower than where you want to run? It’s called cold tire psi. Nothing new. When I raced karts we ran nitrogen in our tires which helps with the fluctuation down as the tires heat up. Some tire shops use nitrogen for this very reason.

 

[fredcook]

I used to check tire pressure religiously before every ride at the trail head, and sometimes after. Fast forward 30+ years... I now check tires once a week, while riding as many days a week as possible. I just ride!

Sooo... Does anyone check their car tire pressure before and after each drive? Just wondering.

 

[Chicane32]

I used to check tire pressure religiously before every ride at the trail head, and sometimes after. Fast forward 30+ years... I now check tires once a week, while riding as many days a week as possible. I just ride!

Sooo... Does anyone check their car tire pressure before and after each drive? Just wondering.

Your not comparing apples to apples. Car tires don't use tubeless sealant and don't lose 2-4 psi sitting in the garage after a few days.

 

[127.0.0.1]

I used to check tire pressure religiously before every ride at the trail head, and sometimes after. Fast forward 30+ years... I now check tires once a week, while riding as many days a week as possible. I just ride!

Sooo... Does anyone check their car tire pressure before and after each drive? Just wondering.

I do a look at all 4 tires for sag on trucky each time I go to drive it, just to be sure none are or have gone flat. then rely on TPMS to tell me if they go low. once every 3 months I go around and reset them all to 35psi and judge each one current pressure to know if one is leaking more than the others

 

[Forest Rider]

Is this thread valid for summer time only?

Will you still see a 2psi increase in the fall when it's 54 degrees? What about if we ride in summer on an overcast day?

Probably not. Meaning the rider will have to change their tire checking strategy seasonally. LOL

 

[Jayem]

Is this thread valid for summer time only?

Will you still see a 2psi increase in the fall when it's 54 degrees? What about if we ride in summer on an overcast day?

Probably not. Meaning the rider will have to change their tire checking strategy seasonally. LOL

In the winter, I have to "overpressurize" my fat-bike tires for snow riding, because the pressure when I'm out riding at 5 degrees F is significantly less than what I inflate indoors. If I was setting it to "riding pressure" indoors, I'd be hitting my rim and folding the casing all over the place while riding. Temperature has a huge effect. Sometimes while riding we have to add some psi just due to drop while riding. With fat-tires, it almost always pays off to adjust the pressure up or down, rather than try to make a less than optimal pressure work, because you'll lose significant traction when too hard or be bogging while pedaling/folding while turning. A half a PSI change in these tires can make a significant change. Not so much with smaller/narrower tires.