B1KE

Hey everyone,

I was reading some people run their tires in between 80-100 for a more plush ride. My current 25mm tires are listed as 110-125 PSI. If I run them under do I risk getting pinch flats, compromised speed/handling? What are the pros and cons of running below recommended tire pressure?

datlas 

You are almost certainly overinflating your tires. Try 90PSI. Risk of pinch flats depends on your weight and riding conditions.

B1KE

Thanks for you opinion. I weight 180lb 79kg if that helps. Why are the labels in the tires listed with such high PSI and the range of 110-125 is so little when in fact you can run them at 90.

What tire pressure would you recommend for me based on my weight?

hogger453

Talks about punctures and inflation pressures.

B1KE

Thanks for the informative video but there was no mention of the pros and cons of running tire pressure under the recommended amount listed on the tire which is the original purpose of my thread.

PepeM

Pros: Smoother ride
Cons: Not many until you go too low and start getting pinch flats

fa63

Presumably, the tire assumes its optimal shape for maximum grip / minimum rolling resistance and optimum wear when inflated to within that range.

At 180 lbs, you might want to try the lower end and see how it feels. I have found lower is not always better, especially with supple, high TPI tires like Veloflex and Vittoria.

dorkypants

Try my page of road bike tire pressure calculators, with links to the sources:

dorkypantsr.us/bike-tire-pressure-calculator.html

79pmooney

I pay zero attention to the manufacturers' limits. I inflate them to the best pressure for my riding. It is a compromise between grip, rolling resistance and comfort and will be different for different both sizes and types of tires. Also different on different days (weather), roads and length of ride. (One piece of equipment I always have is a good frame pump. No gauge but plenty of oomph to get any pressure I want easily.)

Ben

ThermionicScott 

+1. None of the front tires in my stable are even up to the minimum recommended pressure listed.

The tire companies don't know how much you weigh, so they have to slap on a number that'll prevent enough people from getting pinch flats, and subsequently mad.

znomit

I always inflate to the max pressure to seat the tyre and tube properly, then back it down to ~90.

FIVE ONE SIX

i'm 240# and i run my S-Works Turbo 24's at 110 rear and 105 front, they ride as smooth as my old tubeless IRC's and i can't remember the last time i got a pinch flat in 12 years of riding...

Rowan

Yes, and you and I are long-distance riders, which means comfort is as much of a premium as rollling fast. There is a compromise in that case. But I do know that with the current tyres I have (Conti GP4000S II in 25mm width), at my weight of 83kg, running them at 90psi is a really nice pressure for the three-way -- comfort, lower rolling resistance, and not getting pinch flats (in fact, I could probably run these at 60psi and still avoid pinching them).

I was first turned on to lower pressures about a decade ago when I pumped up some wider profile tyres to their maximum pressures (around 100psi) for a 300 or 400km rando. Boy, was my butt minced beef after that little (major) error! Never again. Even at 23 and 25C, I now run around 90psi.

ahanulec

I run my 28c tires at 80/85 fr/rr. Even at 270 lbs I haven't had any pinch flat issues.

Pinch flats are the biggest concern. Maybe the only other would be unseating the tire in a corner, but I think the bead coming loose would require pressures much lower than you could ride anyway.

I'm amazed that these tires have a 120max psi rating. It would be like riding solid rubber at that pressure im sure.

rpenmanparker 

Pinch flats are not the major concern. Rim damage is the major concern. Pinch flats are just the "canary in the coal mine." They provide early warning that you are risking rim damage.

Experts advise a certain level of tire "drop", compression under load. Usually the recommendation is 15%. When you find the pressures that provide that level of drop (there are generic charts and graphs online) you will have a reasonable approximation of the "right" inflation. Actually if you have a trainer stand, it isn't hard to measure for yourself...with the help of an assistant. Just remember that the front pressure will need to be lower than the rear to meet the standard.

Consider the manufacturers' recommendations to be safe upper limits not individualized suggestions for you.

Jean_TX

If I remember correctly, either Jobst or Sheldon said in a biking newsgroup that the PSI on a tire label is usually a "maximum recommended" pressure. It is determined by a manufacturer by inflating the tire as high as possible on various rims and noting when the tire blows off the rim, then a fudge factor (for the lawyer's sake) is applied. Some tires also list a "minimum recommended" pressure which sorta represents the lowest PSI such that the tire won't roll off a typical rim.

ptempel

Just fill them up to get a little sag and thats it. It also depends on the rim width. The wider 23mm rims like Velocity A23 and Kinlin XC279 can allow you to reduce the pressure by 5 to 10 psi. I have the Velocity ones and run 90 psi front and 100 psi rear and that's been plenty for me. And I'm a fairly heavy rider at ~220 lbs. I also reduce the pressure a bit on rainy days.

AlexCyclistRoch

I generally run my tires at 75/95, but when I ride on particularly crappy roads, I will go as low as 60/80, but then, I use tubulars, and I have **NEVER** had a pinch-flat.

tarwheel 

I would certainly not exceed the max pressure ratings and there is little need or advantage to matching them. However, at your weight, the risk of pinch flats is very real if you run the tires at too low a pressure. I'm about your weight, and I inflate my 25 mm tires to 105 PSI rear and 95 front. I wouldn't mind running 5-10 PSI less but wouldn't risk lower than that for 25 mm tires.

I personally haven't noticed an improvement in comfort running tires that are low on pressure, but I have noticed a greater susceptibility to pinch flats at lower pressure and once I had a tire roll of a rim on corner (fortunately I was going very slow at the time).

Doge

How can you say that when the OP does not give weight or inflation pressure and you also don't know the road or brand/type of tire?

Doge

I live in SoCal. My son now lives in CO. It depends on lots of things. The flex/suppleness of the case and tube material matters to resistance. A supple tire you have a wider range of useful pressure. A stiff, butyl based sidewall and tube absorb a lot of the energy in deforming and I like more pressure to minimize how much they flex so there is better rolling resistance.

In SoCal there are lots of goat head thorns, broken glass etc. You just are going to get flats riding on anything nice - around here. I (230lbs) prefer a higher pressure 25mm Veloflex clincher, because other than the sharp objects, the roads I ride on are pretty smooth.

When he lived here my, son mostly road 2nd hand tubulars of the tougher variety (except for racing) and he still got glass cuts. Maybe 1 flat / 3,000 miles - which is good - here. He ran 23s at about 110/100. Racing 25 silks 115/110. Racing cobbles long (Paris Roubaix) 27mm 70psi. Cobbles short 25 silks 100/90. For TTs on that same bike he'd go 125/115 but I can see on the rougher road could have gone 15PSI lower. So it just depends on weight, road, derbies and tire and tube material and risk.

In CO he's riding (@ his weight of 155lbs) 27mm Velofex Vlaanderen about 85-95PSI as he does a combo pavement and gravel. Roads are rougher, but have fewer sharp objects.

I think it is hard to beat a Veloflex for all around.

Reynolds 

I used to run my 23s at 100/110, but experimented a little and found they ride better at 90/100. Even as low as 70/80 they ride OK, but the risk of pinch flats/rim damage increases if I hit a pothole. My weight is 68kg/150lbs BTW.

chip1

I once rode my friend's Giant Defy for a day with 23mm tires and remember how comfortable the ride was. I thought of getting one for myself because I was so impressed with it. When I got the floor pump to pump it up at the end of the ride however I realized the psi was barely over 40. No pinch flat the entire ride.

Chandne

I run less with tubeless (85/90) but with tubes I currently run 95/100 0r 95/105 if smooth roads. I'm 175-180 now. I'd type more details but the Moscow Mules (and I rarely drink nowadays) are taking over.

Seattle Forrest

Please remember what's printed on your tires is the MAXIMUM pressure, not what you should do.