RH recommended tire pressures

[Patrick Moore]

I’ve been thinking about tire pressure recently, as I recently rode with a friend who insists on pumping his 38s to50 psi or more, while I pump my 28 mm (actual) Elk Passes to 55F/60 rear, my 32 mm Stampede Passes to 50/55, my 41 mm Naches Passes to 35/40, and my 54 mm Thunderburts at about 18 psi. I’ve been finding that the SPs might do better at 45/50 and the NPs at 30/35. I’m a bit more than 160 and the bikes with usual luggage weigh (guessing; first number ready to ride but no luggage, second is guestimate with usual luggage (Gofast: 18/19; Roadeo: 20.8/21.8; Errand with NPs 26/30; road bike for dirt 30.5/33.)

So it was fun to enter the numbers into the RH pressure calculator and find the following; the second set is my actual range. Rider + clothes, let’s ballpark at 165.

RH               Historical Actual

EPs: 60-75 / 55-60

SPs: 49-60/ 50-55

NPs: 35-43/ 30-40 (I often carry heavy loads on this bike, mostly on rear but sometimes adding weight in front).

TBs: 27-33 / 17-20.

Other pressures: 72 mm WTB Rangers: 13-15 psi; 22 mm Spec 26x1 Turbos, 22 mm Conti GPs,  22 mm Mich Pro Race: 80-90.

I’ve been using these pressures for years on surfaces ranging from dinner-plate smooth to rough gravel and, on pavement, often over 8” or wider pavement expansion cracks.

I never, never, never, never pinch flat; the only time I’ve pinch flatted in the last 40 years was when I deliberately ran a 22 mm actual Specialized 26 X 1 Turbo (200 grams) at 80 psi in front into a pile of large gravel to see what would happen. Yes, I got a pinch flat.

I’m curious to hear from others what I’m doing wrong.

https://www.renehersecycles.com/tire-pressure-calculator/

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Patrick Moore

Alburquerque, Nuevo Mexico, Etats Unis d'Amerique, Orbis Terrarum

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[Guy Jett]

In the olden days I always pumped my tires to the max listed on the tire sidewall.  In my ignorance that seemed acceptable.  And it often was for the 1 to 1-1/4 inch tires run at the time.  In general, the higher the pressure the better.

I first encountered the idea of running at lower pressures through the work of Frank Berto.  His work documented lower pressures in terms of a percentage drop for the tire height.  Lower pressures were often advocated as the actual weight of the rider was less on the front of  the bike than on the rear.  See "Tire Pressure Take-Home" on the Rene Herse website for a summary.

After many years of real world testing Jan Heine of Rene Herse (formerly Compass Bicycles) demonstrated that running tires at lower pressures actually made the ride both more comfortable AND with either no loss of speed or, indeed, some slight increase in speed.  Many of the articles at the Rene Herse website document the science and the statistics behind this research. He eventually published a "Tire Pressure Calculator" yielding a "soft" pressure and a "firm" pressure that were very near equal in performance allowing some user flexibility. In contrast to earlier low pressure recommendations Hene advocated for using the same pressures front and rear as, under braking, the weight on the front could exceed the weight on the back.  Note that inputs for calculating these tire pressures are bike-rider-gear total weight and tire width.  One limitation is that tires less than 25 cm (1-inch) width are not considered.  Jan also make clear that the recommendations are just good starting points for experimentation.

Silca also has their "SILCA Pro Tire Pressure Calculator" which calculates pressures for narrower tires down to 20 mm.  The inputs are also much more complex where, in addition to total weight and width, the user is also asked to input surface conditions, a qualitative "average speed", a "tire type", and your front and rear weight distribution.  In general these recommended pressures are slightly to significantly higher than the Rene Herse recommendations.  The science behind Silca's calculation is not clear.

I currently  use the Rene Herse calculator to run my AHH with 650B x 38 tires at 40 psi, and my Raleigh Competition  27 x 1-inch fronts at 74 psi and 27 x 1-1/4-inch rear tires at 47 psi.

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[Patrick Moore]

Yes, I recall the utter horribleness of  35 mm Specialized Fatboy 26” slicks pumped to the 100 psi or so on the sidewall label. On smooth pavement they were fine, but cornering on bumpy pavement had the rear wheel skittering around. And I wondered at the time why Spec 26 X 1” Turbos at about 22-23 mm and 100 psi felt so much smoother.

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[Jason Fuller]

I learned somewhat recently that my Lezyne floor pump's gauge is terribly inaccurate, and so everything I thought I knew about my own tire pressures, which I never really paid a ton of attention to in the first place, was wrong. I was running considerably lower pressure than I thought I was. 

I'm of the opinion that if you have on-the-supple-end-of-the-spectrum tires, the ideal pressure is the lowest pressure you can get away with. I rarely pinch flat, but certainly more than Patrick - whether it was a mis-timed curb hop, or root that I didn't see due to leaves while under-biking some singletrack.  That said, I am not scientific about it at all - I give my tires a squeeze before a ride, and if my thumb can't squish the tire more than a quarter the way to the rim or so, I'm good to go. I tend to run my 40mm tires at around 30 psi (real world), 47mm tires at around 25 psi, and 3" tires I'm not even sure but well south of 20 psi. But in reality I pump them up a bit beyond this and leave 'em alone for a month or so.  Usually a gentle rim-kiss will let me know it's time to add some air before it turns into a pinch flat. 

[Patrick Moore]

Once I was commuting home at dusk without lights (forgot them; that’s why people use dynamos) I misjudged a sidewalk handicapped ramp and bashed my front wheel against a 2” or so concrete vertical. I was riding the 1999 custom Riv Road 26” fixed with 22 mm actual 650C/571 bsd Conti Grands Prix at, I guess, about 90 psi. The blow was enough to bend the fork — I rode it home feeling very tippy — but it did not pinch flat the tube. Very strange. 

On Mon, Nov 3, 2025 at 8:25 PM Jason Fuller <jtf.f...@gmail.com> wrote:

…  I’m of the opinion that if you have on-the-supple-end-of-the-spectrum tires, the ideal pressure is the lowest pressure you can get away with. I rarely pinch flat, but certainly more than Patrick - whether it was a mis-timed curb hop, or root that I didn't see due to leaves while under-biking some singletrack.

[Ben Miller]

I agree with Jason: pressure gauges tend to be extremely inaccurate and can only be trusted in comparison to that gauge and even then they drift over time. 

That said, pressures I run measure out to be lower than RH recommends for "soft" and I don't believe I have ever pinched flat (maybe I am mis-remembering? But I rarely flat either way). 

I've only ever tried to be "scientific" about high volume tires at very low pressures. I got a dedicated low pressure gauge for that, but recently blew the gauge out by accidentally using it on a tire pumped too high :(

[Steve]

"I’m curious to hear from others what I’m doing wrong."

Nothing!!!   Sounds to me like you've found the sweet spot for each of your bike/tire combos based on your riding style and the surfaces you ride them on. 

Steve in AVL 

[Nick Shoemaker]

@Jason: that is essentially identical to my own experience! A very optimistic Lezyne pump means I've probably been riding well below recommendation pressures for the better part of 10 years. If I feel a rim-kiss, I typically just keep riding and try to use better technique. Once the 'kiss frequency picks up I begrudgingly stop and air up the tire on the spot (using a pump with no gauge!). So far I have yet to pinch flat on my 2.6"/Cliffhanger setup & the rims seem to be holding up just fine...