I weigh 220lbs and run 95 psi in the front and 100 psi in the rear. I consulted two bike mechanics after reading on lower tire psi and they said to stay at those numbers for my 23mm clinchers. Never had a pinch flat.

The post on the flow site shows that you need not run much higher than 95 psi, even as a Clydesdale.

http://flocycling.blogspot.com/...re-pressure.html?m=1

This article would suggest higher pressure closer to 115 psi rear and 105 front (assumes 55% rear and 45% front):

http://road.cc/...eed-comfort-and-grip

As long as you don’t pinch flat you are better if you are below optimal pressure. Being above optimal pressure can be very costly time-wise.

The Flo study actually says at the bottom, despite the graphical contradiction, “Riders over 180 lbs or 81kg are advised to inflate their tires to the maximum pressure recommended by their tire manufacturer without exceeding 150psi or 10bar“. This is the stuff that confuses me. This implies I should run 120-130 if that’s what the tires call for...

If I were you I would try lower pressures. I think the risk of pinch flatting is overestimated, as most don’t ride aggressively enough to end up with a pinch flat.

You will be faster at lower pressures, even if you feel slower. Pick a course and ride it at different pressures say 5 psi increments. Record your rides and compare speeds.

I would ignore the note on fhe Flo site, it sounds like a legal disclaimer and obviously contradicts the purpose of the study.

I have been as heavy as 230 back when 21mm tires were the thing and even then never ran more than about 115 psi. I am 200 now and run 90 to 95 psi with 25mm GP4000's.

rich

I weigh in between 220-245lbs. I haven’t pumped my 25mm tires beyond 100psi in years and I’ve not had any problems. Usually run about 95-100 now.

Even back in the day when I was getting started on the road at 265+ I never went beyond 105.

I train and race on 25mm GP4000s on Flo wheels. The Contis measure about 27mm on those wheels.

I weigh 210 and run 98-100 psi in the rear and 95-98 in the front. I ride on some pretty crappy roads so error on the side of comfort. But, I do alot of group rides where I can not always see what is in front of me so I regularly hit some decent sized pot holes at speed. I do get one or two pinch flats every season but those only come after hitting something hard enough I marvel at the fact my rim is not broken. I've hit holes hard enough to knock the bottles out of my cages and still not pinch flatted.

I started riding way back in the days of 19mm tires and would get at least one pinch flat per week. Modern tires are a million times better than light weight clinchers of old. I really don't worry too much about pinch flats these days.

That is older data that you are looking at. We are working on a better way to represent tire pressure, but it's not quite done yet. That said, I don't think you need the max PSI in your tires if you are over 180 lbs. Everyone will vary but you can experiment with lower pressures, as long as you understand the risks of going too low. For example, I weigh 155 lbs and can easily ride at 80 psi. But, that doesn't mean I should go for a ride at 30psi. For heavier guys, maybe start at 110-115 psi and make small adjustments from there. And so I keep my attorney happy, just make sure whatever you are doing is safe.

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

I'm 220, and currently running 23mm GP4000s on Flo 30s and 60s. After spending an afternoon of testing various tire pressures a few years back, I found 95psi to have the lowest rolling resistance for me. 4 years running at that pressure, and not a single pinch flat yet...

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"I'm thinking of a number between 1 and 10, and I don't know why!"

Good info. Thanks for sharing.

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

I switched to GP4000ii's and have latex in them for a race this weekend. Have been doing 80-100mi rides on butyl with Mich Pro Service Course 4's at 110psi in the back and 105 up front. I'm 240 and ride a Blue Triad that can only run 23mm tires because of chain stay and brake width.

I'm around 250 and run 25mm Specialized tires (the turbos, not the cottons - and now that I look, they're listed at 26mm) at around 90-95 psi without a problem.

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@brad_glasgow