prj71

Not the worst idea!! They tax the hell out of us anyway and take too much as it is.

PeteHski

60 psi for 32 mm tyres is not dumb. For me 80 psi is above the maximum pressure for my 30 mm road tyres. So that really would be dumb.

What tyres are you running out of interest?

79pmooney

My latest tubulars are rated 115-200 psi. Should I average that, subtract 5 psi and ride? (152 psi in 28c tires. Ought to be fun! And guarantee naked, toothless babies. I might go toothless also.)

shelbyfv

"It's more like 70-80" according to whom?

smd4

Nope, just to the pressure on the sidewall.

prj71

Conti Grand Prix 5000. Max tire pressure is 102. Lowest I run them is around 70psi when I know my route will be on some bumpier roads. Nice smooth road routes and I'll bump them up to 80 psi. 60psi I can start to feel some rolling resistance.

I also have some Conti Terra Speeds 700 x 40 that will fit on the bike. I will run those at 50-60 for gravel riding.

terrymorse 

Old habits die hard.

prj71

According to me and where and how I'm riding. It's called "ideal" tire pressure and not "correct" tire pressure.

Ideal pressure is about finding a balance between reducing rolling resistance and increasing comfort. And that's different for everyone. Real world road conditions, make up of tire (higher or lower TPI), rider weight, normal riding position, tubed or tubeless etc. and not some silly mathematical formula or chart, will dictate what the tire pressure needs to be...And that is determined by experimentation.

mflacche

The calculator gave me 63.4 psi front and 67.4 psi rear for road riding. I have 700c x 28 tires on a Canyon Ultimate CF SL 8. I have been running them between 70 and 80 psi. Maybe I will try the lower pressure, or at least the differential of 4 psi between the front and rear.

tomato coupe

That's impressive, considering the measured rolling resistance of a 32 mm GP5000 differs by about 1 W at 60 psi versus 80 psi (at 18 mph.)

shelbyfv

Obviously it suits you and frankly your WAG method is probably adequate for most of us. That doesn't mean that it's "just dumb" or a joke when some folks want to dig a little deeper.

PeteHski

The Zipp/SRAM guide doesn't claim to give you a "correct" pressure. It's a guide based on the relevant parameters and their experience. The variables you just listed are exactly those included in the calculator to give the user a more educated starting point, especially when moving to a different tyre or rim width.

tomato coupe

In fact, they even state that at the bottom of their page:

Eric F 

I'm running the 700x37 tires on my gravel bike at 40psi. 50+ was a bit too harsh for my taste.

7up

I was thinking of my car tires LMFAO! The highest PSI for a road bike is 130-160 ……….. there are no 200 PSI as of yet that I’m aware of on the market.

wolfchild

Tire inflation is one of the most simple things about cycling, there is no need for any expert advice. Every tire I ever purchased already has minimum and maximum inflation pressures printed on the sidewall. Some of my pumps have a pressure gauge and some don't but I don't even look at it anymore, I just go by feel according to the terrain that I am riding in.

timtak

The roads are smooth here (often as smooth as a track) and I find that the higher the pressure the fewer (none in the past year) flats I get because glass gets pinged away as opposed to having the time to bed into a softer tyre, so I go to pressure on the side-wall which is 110 psi on the tyres I now use (Wiggle's Lifeline Road). I hate flats.

I used to go to about 140 PSI, which was limited by my ability to pump, in my TUFO tubulars because flats were even more of a pain (despite all the goo I tried). I did find that the palms of my hands did not like 140psi but I put extra, 100 yen shop shoe sole silicon padding (like this) in my gloves so even then, the high pressure was not a problem, except for the road resistance, so they say.

Eric F 

When I made the switch to tubeless tires, I asked for tire pressure advice from folks with tubeless tire experience, who ride similar bikes to mine, because it sped up the learning curve with something that I was just starting to learn about. Although I could get by just fine using the squeeze test to check tire pressure, I prefer the consistency of using a pump with a gauge.

PeteHski

This thread is living proof that some people are clueless about tyre pressure. Some tyres have min and max pressures and some just have a max. One set I have has a min 43 and max 73 psi. But the recommended pressure for my weight is 60/65. Of course I could just guess, but it’s actually very simple to take their advice. I’ve never yet found it to be bad. I might tweak them a bit, but usually they work well at recommended pressures.

Do you just guess the tyre pressures on your car/motorbike as well, based on “feel”?

PeteHski

Probably perfect then, if you weigh 300 lbs.

smd4

Perfect for me, but no, I’m not that heavy.

wolfchild

Your bike vs car analogy is comparing apples to oranges....Underinflation or overinflation on a vehicle can be a serious safety risk and kill somebody if that tire blows off the rim while driving at a freeway at the high rate of speed and in case of underinflation you will get poor fuel economy....On a bicycle the worst that can happen with underinflation would be a pinch flat and higher rolling resistance..... Overinflating a bicycle tire to a point of it blowing off the rim would be difficult especially with a mini pump and only an idiot who lacks common sense would be able to do it, and you'll get a very uncomfortable ride which most normal people would not put up with.

wolfchild

How can you say that ?....when large majority of cyclists on this forum and out in the real world don't use any online calculators and never seem to have any serious issues related to tire pressure.

PeteHski

So I take it you set your car tyre pressures to the recommended settings, but you think that would be overkill or too complicated for bicycle tyres.

wolfchild

We functioned and inflated our bicycle tires using our common sense, but today the world we living in online calculators replaced the good old fashioned common sense.