Tire pressure
 

Hi all,
I have a 70's road bike, as I'm sure some of you are aware.
Two questions:
What pressure should the tire be set at for riding?
And ..... I may, or may not, put it up for the winter, depending on the weather.
If I put it up, what should I set the tire pressure at, and ... should I suspend it?
Thanks,
..... john

A web search will give you various calculators for determining tire pressures based on tire size and load. For example: https://sport-calculator.com/calcula...ure-calculator

I recently did some of my own calculations, based largely on the work by Frank Berto years ago, to determine what width tires I should get for my new (to me) and now fully restored 1981 Nishiki International, and what pressure I should be running in my '73(?) Bridgestone bike that has 27x1¼ tires.

I cannot speak authoritatively about bicycle tires as I have far more experience with collector cars and their tires than with bikes, but I would suggest that taking your bike off of the ground for winter storage (or any time it is not being ridden for a period of time) is probably a good idea.

I just ran that calculator, seems off from what I’ve seen on other calculators like the Rene Herse calculator. Is recommending a much higher pressure that Rene and higher than what I run and know works.

22mm pista tires - 90F/100R
25mm & 27 mm road tires - 70F/80R
30mm & 32mm road tires - 60F/70R
35mm & 38mm gravel tires - 50F/60R

I see too much difference between front and rear pressures with calculator in #2. But the avg of the two isn't a bad starting point.

Remember = there is no perfect/correct tire pressure for everyone.
Too many hard variables. Too many personal preferences.

I know from experience that if I ran those pressures on my bike with 27x1.25 (32mm) I would get pinch flats, but then I am a big guy who carries touring accessories.

and to think I ran 10atm on the track 50 years ago. Clement No.1’s

I do think in the initial question there is not enough information to answer. Rim type, tire size, rider weight…

as for a storage, suspended always best, out of the sun ( many garages have windows )

Here's an alternate calculator that gives "soft" and "hard" recommendations:

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

The link on the bottom of that page "The Science behind the tire pressure calculator" shows how the "soft" and "hard" values were obtained and is, in my opinion, pretty good.

I have also seen different opinions on F versus R pressures - some say rear should be higher because it carries more weight, and some say they should be equal because of the forward weight transfer during braking.

Yes this new low pressure trend is ridiculous, and this is from an experienced amateur rider who took part in sanctioned road races for many years in the past since the mid 80's. I'm in a lighter range of weight, low 160's and less but have done many aggressively ridden Criterium races and can say first off the under 100 psi with narrow tires whether 23mm or 25 is a bad idea. Too much tire flex in turns/corners, (this can cause a nasty surprise even a crash) lost efficiency on the majority of smooth asphalt sections of route, Even handling wise the softer tires hurt the bikes handling precision, undermining the headset function. So for many guys heavier than me, I'd stick with 110 psi. For my weight I can get by with 100- 105. To run a little lower than 100 always gives me a negative result on the road. If you weigh well over this in the 175 and over range, I'd be cautious on less than 105 psi, but even there, you must take notice of how the ride is and if more likely to get pinch flats as you keep an eye on what the tire sag is like out on the roads, just don't get fixated on them whislt riding!

As always, ymmv. :)

Especially with tire pressure. Wait until there is a lube thread.

Random advise on the internet is worth what you pay for it. You have bike and tires in hand. Try different pressures and see what you prefer.

lol!

As I mentioned, I've spent time on collector cars in addition to vintage bicycles, and on the topic of engine oil selection, just one car-model specific forum threads on this has 9,984 views and 135 posts.

your tires say what their max pressure is... try running about 70 to 80% of that max pressure...
then try 60%... then 90%... then go for max pressure.... pick what felt right for your riding habits... never go lower than 60%, unless you weigh less than 125lbs or so.

i run about 75-80%, and weight about 225 now... i've also slowed down quite a bit in the last decade..

2.2Lb. per Kilogram, if that is a factor...

Thank you all for your help. The calculator at https://www.renehersecycles.com/tire...re-calculator/ says that I should be using 48 or 59 psi. I think I'll start with the lower value for a more comfortable ride.
Thanks again,
...... john

I haven't read all the posts here but I do not see any from the OP that tell us anything about the rims he is using. First, sewup or clincher? If clincher, steel or aluminum? Width? Are the inside flange walls straight or hooked? Basic but important stuff.

If sewup - pressure, both max and what you want ride are dictated by the tires, not the rims. If clincher, the rim width makes difference and a rim without hooks means that too much pressure will very likely blow off tires pumped to levels were expected to ride in the 1990s.

So, @shinnen, more information please. Anything you can tell us about the rim type, manufacturer, model and size will help. I wouldn't run more than ~70 psi in my old Peugeot with its steel Rigida rims (probably 1-1/4 tires) but I had race cohorts that were using high pressure in the skinniest clinchers they could find with the Weinmann Concave rims of 1977. (And I did the same with mine on my Peter Mooney.)

Amen, brother! I run my Veloflex 23’s at the max and frequently get told by the know-it-alls around here how much more enjoyable my ride would be if I ran them at half-max.

[Spoiler alert: doing so makes the ride suck]

Printed tire widths are based largely on narrow rims. So if you are knowingly using wide rims, go to at least one size larger on the chart. Or measure the tire as mounted.

Take a measurement as well. I have had multiple pairs of tires that when mounted on a wide rim, run wider than spec themselves. As example, the 28mm GP-5000 S TR tires I purchased in April, mounted on a 30mm wide Hunt wheel, run 30mm. OTOH, the GP5000 AS TR in 32mm on those same rims run exactly 32mm

Trend? Ridiculous?

First, I have been north of 175 since the late 80s. I was a scrawny 6'1" outside linebacker in high school, but I put on a lot of muscle mass working as a landscaper to pay for college. The now banned (and rightly so) creosote-soaked railroad ties used for retaining walls were damn heavy. Schlepped hundreds of them back in the day.

And I have experienced the tire flex (I call it tire flop) you write about. But I really don't even detect it under 60psi, and really feel it at 30-40psi, depending on the width of the tire. I did get a pinch flat, once. Hit that pothole square at 25-30mph. Not really a surprise.

The point being, you are more than welcome to run high pressures. But you certainly don't have to and I prefer the low pressure over the high. Again, ymmv.

Got it! Thanks.

I like 90. I don’t like squishy tires.

I use the SRAM and Silca calculators. They agree within a couple psi. I’m 175 lbs and on my modern bike running 28mm clinchers pressure is set to approx 70 psi, on my vintage bike with 23mm tubulars pressure is set to approx 110 psi.

Hi mooney,
I really can't tell you much about the wheels. It's a vingate circa 1970s roadbike with 27 x 1.25 inches wheels. That's about it. I thought it would be fairly easy for members, who ride this bike (or facsimile) to chime in on what psi they find most comfortable; what they would not go below and what they would not go above. I weight about 170 lbs (I'm not sure what the bike weighs). Comfort is high on my agenda. I won't be going long distances, just tooling around the local area, no highways, my balance isn't what it was 50 years ago.
..... john

The "rule" I was taught as a beginning bike racer was 5 psi less in front. I've been doing that nearly 50 years. It works. (For drop bars, the usual weight balance front and rear and a fair amount of forward lean.) Less in front is probably "faster" but that moment I am fully on that front brake to stay off that truck bumper and the deep pothole appears - well for that millisecond, I want all that pressure! (Basic fundamental rule of bike racing I was taught - minimize crashes. They cost training, money, race results and sometimes whole seasons.)

Hi SurferRosa,
"Don't overthink it. Use an online calculator for road (firm) use with 32mm tire width and 200 total pounds.
The Sram calculator (https://axs.sram.com/guides/tire/pressure) provides the answer of 60 psi (front) and 64 psi (rear)."
As mentioned above, I used the calculator here https://www.renehersecycles.com/tire...re-calculator/ suggested by dw01 which says 48 to 59 psi for my weight (incluing bike), so I'm going to start there.
.... john