Tire pressure lower than the minimum recommended level

[cyan]

I see lots of discussions about optimal tire pressure given rider's and bike's weight, tire width, road condition, etc.

So I tried a few calculators and charts online, and the optimal pressure for me seems to be 85psi rear and 80psi front for my 25mm tires.

Now I'm running Vittoria Rubino Pro 25mm, and the officially recommended range is 100-130psi. I'm slightly worried that by running at 80-85psi it is significantly lower than the official minimum, and I wonder what gives here. Is the tire material also a significant variable here (290 TPI Corespun for mine, whatever that means) such that it may affect the optimal pressure level considerably?

[Peter P.]

I don't know what's behind the logic of the tire companies.

But I can say I've never heard or seen tire failures directly related to violating the recommended minimum tire pressure stamped on the sidewall.

I'm currently using different brand tires on each of my bikes; Panaracer, Ritchey, Michelin, and Continental. I'm well below the minimum on all of them and experience no problems. For the Ritchey tire (ATB), the minimum is 45psi.. There's no way anybody I know would or could ride with such high pressures off-road. I run 26-28psi. .

Your questions are good in trying to gain knowledge and an understanding of the manufacturers' logic and I'd love to know the answers myself, but if all you're interested in is "can you violate what's stamped on the sidewall without repercussion" then I say absolutely.

[ultraman6970]

The problem in general (im not familiar with that clincher ok?) is that if you go too low the tire or tubular will flex way too much and you actually can get punctures and dent the rim in the process aswell. Tire with too much air and will get too hard and actually you can get punctures for that reason, that the tire says max 200 psi doesnt mean you have to put that.

So there's a sweet spot that IME with clinchers and tubulars is between 85 and 100 psi depending on the brand, model and how heavy you are aswell. But if it feels ok for you to go tad lower than the recommended psi, I do not see why not you know.

[soulspinner]

How wide is your rim supporting those tires? When I went wider with rims tire pressure can be much less.........................ymmv

[Davist]

for tubed tires, too low and you risk denting/bottoming out on the rim and rolling the tire bead right off. I've dented rims in bad potholes I didn't see, and rolled tires off of MTB rims (narrow rim, fat tire days 20+ years ago).. I don't think you'd see either at 80psi. I run about 70-80 with 28s on 25mm wide (outside) rims and weigh 195 or so give or take a burrito.

[Red Tornado]

Are there any tire pressure/inflation apps that have given anyone here good data and results? I've found a few, but ratings on Google Play Store are low and not sure if there's something else I'm missing.

[oldpotatoe]

I see lots of discussions about optimal tire pressure given rider's and bike's weight, tire width, road condition, etc.

So I tried a few calculators and charts online, and the optimal pressure for me seems to be 85psi rear and 80psi front for my 25mm tires.

Now I'm running Vittoria Rubino Pro 25mm, and the officially recommended range is 100-130psi. I'm slightly worried that by running at 80-85psi it is significantly lower than the official minimum, and I wonder what gives here. Is the tire material also a significant variable here (290 TPI Corespun for mine, whatever that means) such that it may affect the optimal pressure level considerably?

I think they care little for comfort and are trying to minimize sidewall damage after hitting something but ride carefully and find the PSI that suits ya..IMHO. The tires I use say 115psi..I use 85..and I'm .1 offa ton.

[Kontact]

I've seen this topic before, and the upshot was that the "minimum" tire pressure listed by tire manufacturers was in reference to something you actually don't need to worry about and you should ignore. It isn't for pinch flatting.

So use 80/85.

[Hilltopperny]

All good advice. Even when I’m at my heaviest which is 230ish I run about 95 rear and 85 front. Haven’t had pinch flat or any other mishaps with those pressures running supple clinchers.


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[Avispa]

I see lots of discussions about optimal tire pressure given rider's and bike's weight, tire width, road condition, etc....

Yes, even the kind of tube and frame and geometry as well... I was able to put higher pressure on the Colnago C59s I owned. Yet I cannot feel comfortable on more than 98psi on my Pinarello Dogma F8.

I don't know what's behind the logic of the tire companies.

Me neither and one has to wonder... I attached the image from a box of Conti 4 Season tire and look what they recommend!

I have come to the conclusion that one almost needs ignore this recommendations and just try out what best for themselves. I have found out that on the 25mm Conti 4 Season I am currently using, I am the most safe and comfortable at 96.5 psi using latex tubes or Foss tubes (vulcanized butyl). I ride on fairly good city roads with the occasional rough asphalt on older roads. I also prefer to use a pump with a digital gauge as I have found the readings tend to be more accurate. Also, I have been able to get away with slightly higher pressure on other brands of tires and wheels, but I prefer not to go too far.

Sometimes I ride on worse rural roads, which have pot holes, gravel and such and I have gone as low as 92/93 psi. I personally do not like to put less than 85 psi or less on my tires as I would be afraid of getting a pinched flat just by hitting a small indentation on the road. Regardless of my feelings, it just doesn't feel right to me on my current set up.

My weight hovers around 135-142 lbs. throughout the year and I use, for the most part, Campy Shamal Mille C17 wheels.

[sparky33]

I think they care little for comfort and are trying to minimize sidewall damage after hitting something but ride carefully and find the PSI that suits ya..IMHO. The tires I use say 115psi..I use 85..and I'm .1 offa ton.


There you have it. Let out some air and add some common sense.

A little experimentation is worthwhile with air being free and readily available.

[choke]

I don't know what's behind the logic of the tire companies.My guess is that their 'logic' comes from the legal department.

[weisan]

I don't read instructions. I go by feel.

[rnhood]

I think its because they are conservative in their approach, and they don't want the tires to impart even a hint of vagueness during a high speed race (or decent in particular). When on a fast descent and you are leaning hard going through a turn in the 40's, you want a very confident feel in the tires. Tire "comfort" is the last thing on your mind. And, that inflation pressure likely assumes the rider is at the top of the weight range. In other words, the rider is big and heavy.

For those that don't typically push that hard, 80# is plenty on a 25. That is the pressure I use, except on recovery rides I often only pump them to 75.

Some rims are more prone to pinch flats and that is something that needs attention if you're riding a road filled with ruts, potholes and imperfections.

[Seramount]

the topic of tire pressure came up during my ride this morning...

on 23s and 150 lbs, I feel very little difference in ride quality using 80 - 100 psi.

in fact, I actually prefer the feel of higher pressure. the bike feels more lively and I feel 'faster'...and that's always a good thing for me.

[charliedid]

I think its because they are conservative in their approach, and they don't want the tires to impart even a hint of vagueness during a high speed race (or decent in particular). When on a fast descent and you are leaning hard going through a turn in the 40's, you want a very confident feel in the tires. Tire "comfort" is the last thing on your mind. And, that inflation pressure likely assumes the rider is at the top of the weight range. In other words, the rider is big and heavy.

For those that don't typically push that hard, 80# is plenty on a 25. That is the pressure I use, except on recovery rides I often only pump them to 75.

Some rims are more prone to pinch flats and that is something that needs attention if you're riding a road filled with ruts, potholes and imperfections.

Agree

I ride 25 or 28 GP4000 at 70-80 on a 23mm wide rim.