read this

https://janheine.wordpress.com/2016/08/22/minimum-tire-pressure/

 

From the Vittoria site comes the following which when attached to the inflation pressure table makes the table to make more sense:
It is impossible to make a general recommendation on inflation pressure for a specific bike and rider, the right inflation pressure depends on too many variables.
Frame and wheel material, construction and stiffness of these, weight distribution, asphalt surface, width and material of tires and tubes, weather and temperature, and not least riding style are the most important variables to find which is the right inflation pressure. In this view the following chart is only a starting point to find the proper pressure and it has not to be seen as rigid rule.
recom_tyre_pressure
For wet or rough roads, decrease by 0.5 bar (7.5 psi). For tubular tires, increase by 0.5 bar (7.5 psi). Minimum indicated pressures can be lowered only in the cases mentioned in the above chart.

The best way to fine tune ideal tire pressures is field testing a variety of different pressures. One method is to use a short criterium style circuit, preferrable with a variety of corners. Start with the suggested pressure and ride a lap. Each following lap, lower the pressure by 5psi until you feel the tires start to “wallow” or move a bit. This is your lowest pressure point. Return to the above table pressures and raise 5psi each lap until the tires start to bounce and skip/move across the surface. This is your max pressure. Decrease by 5 psi from here until you feel you have the best pressure for the conditions.
Keep a tire pressure log, including road surface, techinicality of the course,weather conditions, tire type, brand, and TPI. Finally, the bike you used and your weight on that day. Over time, this log will become a valuable tool for referencing tire pressures and road conditions in order to optimize your performancewhen on race day.

Start with 65psi front and 80 psi rear and go from there. If you do a lot of sprinting you may want to raise the front by another 5 psi.

 

These are incredibly good suggestions.

 

I'm 142 lbs, so I was thinking of going 95 psi upfront and 100 psi for the back wheel. I'd rather avoid pinch flats than have the most confortable ride.

I'm 175 and don't pinch flat at a max of 80f/90r and lots of times it's 70f/80r with re-pumps done at maybe 60f/70r. I've had one pinch flat since '86 (when I switched to hp clincher tires from tubulars).

If I was your weight I'd be on 23mm tires at my pressures.

 

Yea...I ride 320TPI Vittorias and I don't listen to those cranked up PSI numbers. IRL, Roads are too rough for those numbers.

 

I just bought a pair of Vittoria Rubino Pro III tires. There are instructions on the sidewall saying that min pressure is 100 psi and max pressure is 130 psi. That seems very high for a 25mm tire.

I bought these tires on Wiggle, which has the following chart regarding pressure for Vittoria tires (the Rubino pro III are 150 TPI).

View attachment 315873

Which recommandations should I follow? I'm 142 lbs, so I was thinking of going 95 psi upfront and 100 psi for the back wheel. I'd rather avoid pinch flats than have the most confortable ride.

Just how many pinch flats do you see yourself getting? Your plan is to purposely over-inflate your tires thus reducing traction (you go around corners on every ride, correct?) and reducing ride quality (which is 100% of every ride compared to what percentage of time you actually pinch flat....000001%?) rather than inflate to a pressure you'll like more for the 99.9999% of the time you're not flatting?

For 142lb rider, on 25mm tires, depending on rim width, fit/geometry I'd recommend 80 psi rear and 65-70 psi front.

 

Lol, I'm currently at 95/110 on my 25mm aksion tires. Used to run even higher. I'll reduce that at bit with my new tires.

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I'm 175 and I use 85/75 for 25mm tires and we have some crap pavement here. I have NEVER pinch flatted on the road. Most likely cuz I keep my eyes open.

 

You guys seem to run your front tires a lot lower than the rear. When I do that and am going around corners, my fronts seem so spongy compared to the feeling I get from the rear. Also when standing the increased wt make them spongy again.
Do you run more even pressure when under more difficult 'cornering' rides?
Or are you not so concerned with this?

 

Never. It's in your head.

 

I'm 6' 5"/245lbs. I run 25mm conti 4 seasons at 70f/75r for most rides. I never pinch flat. I've tried running higher pressure, and just can't stand the harsh feeling. The bike is a lot more 'connected' on the lower pressures, and it's a *lot* more comfortable to ride.

I might go up 5 or 10 psi in some circumstances, but I avoid it at all possible.

 

I get that it's way more comfortable to run at those low pressures and that there is no real risk of pinch flat. But from what I've read, the rolling resistance increases progressively (check out the bicycle tires rolling resistance website). I'm already used to the harsh feeling, but I don't want to be slowed downy.

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I get that it's way more comfortable to run at those low pressures and that there is no real risk of pinch flat. But from what I've read, the rolling resistance increases progressively (check out the bicycle tires rolling resistance website). I'm already used to the harsh feeling, but I don't want to be slowed downy.

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You are on chapter 1; go back and read the next 3 chapters to understand the whole story and not just part of it.

 

190ish race weight, I run Vittoria Rubino Pro Speed 700x25 and run 90f/95-100r. Never pinched flat in all the years I have been riding, had one sticker flat last season. As Cxwrench said, I am always watching the road to make sure to miss any debris that can cause issues.

 

Keep in mind that the max pressure stated on the sidewall of the tire may be well above the max pressure that the rim is designed for. In other words, don't pump your tire to 130 if the rim is only designed for 110 and this changes with the width of the tire too.