SkinGraft

What Should I pump up my 23c tubes to?

DVDaze

I just go by what it say on the tire.

SkinGraft

yeah im ********

johnny99

Do you pump your car tires up to the max pressure printed on the tires? The max is way to high for both bicycles and cars.

Read "The Case for Lower Tire Pressure": https://www.roadbikerider.com/UArant.htm
Or Sheldon Brown: https://sheldonbrown.com/tires.html#pressure

skydive69

I agree regarding car tires, but disagree regarding bicycle tires. The reason I agree in regards to car tires, BTW, is that the best pressure to run with car tires is the manufacturer's recommendation for the specific car. You can safely ride maximum pressure with a car tire without abnormal wear to the center tread, but it will not be the most efficient setup for the car in question.

When I first started running Specialized S-Works MOndo racing tires to race and train, the LBS owner, with whom I ride, told me to expect about 1000 miles out of them. My current set as about 2500 miles, and look great. I pump them up to the maximum every day. They roll and accelerate great!

DVDaze

Way too high compared to what? I figure the people who made the tire know how much air is supposed to go in it.

Kenal0

It says Max psi not ideal psi. I also fill my Bicycle tires up to within a few pounds of the max but I fill my car tires to what the placard says on the door. I am sure that the same holds true with the bike tire as with the car, as the tire heats up the pressure increases slightly.
KL

92degrees

You need to experiment to find what you like. Keep in between the recommended pressures and go ride. I prefer more in the rear, but keep both on the soft side.

skydive69

The fact that tires heat up and pressure increases (very basic physics) is completely irrelevant in that the phenomenon is considered when promulgating max/recommended tire pressures. Also, why do you assume that the most efficient pressure might not be something higher than the max pressure for your particular bicycle tire? The max pressure for my Continental Comp tubulars is 175 psi. One of the benefits of tubulars is the fact they they are designed for higher pressures. Try taking a run at 115 psi on your clinchers and then 175 on my tubulars and then tell me you aren't rolling better!

meme

I guess it would depend somewhat on your weight and the terrain that you ride on. The lighter you are, the lighter the pressure you can go. At lower pressures, you have more traction, but also more rolling resistance. You have a softer ride, but also higher chances of pinch flats if the pressure is too low for your weight. A lot of MTB tires that I've seen usually publish a range of pressures, while for road tires, they usually only print the max pressure. Don't know what your preference is, but I would not go lower than half of the max pressure on the road tire, maybe something in the 75 percentile...

RC2

We really need to know your weight and tires. I'm 185-190 lb and pump my Pro Race's and training tires to 120rear, 110 front. The pro races are rated to 115 max for some reason, I've never had a problem w/120. Rims rated to 125+. Figure in a decent factor of safety rating is plussed into anything on a rim/tire. That said, higher pressures aren't good for rolling resistance (unless you're on a glass smooth track) and ride harsher anyway.

redfooj

80->90 is comfy for me
100+ is too harsh

davismule

My Michelin Carbons come with instructions that tell me for my 185wt, I should be riding at 116psi.
The tire sidewall states MIN 87psi - MAX 116psi.
In my case, Michelin is telling me the MAX DOES equal the ideal.

samp02

about 100ish for me.

Kenal0

I will try a little higher pressure the next time out. I could use a little less rolling resistance!
Thanks
KL

Corsaire

165 PSI on my Diamante Pros is the best fast rolling set up for me.


Corsaire

johnny99

Read the articles I quoted. I'm not going to copy them here.

My understanding is that most Tour de France racers use around 100psi (a little more on time trials). Maybe uber-fat Americans need more PSI, but not the 150-175psi max that you see on some tires. Too high a pressure and you'll bounce all over the road, reducing efficiency, cornering ability, and comfort.

my58vw

I normally run 125 PSI on my normal tires because of my weight. For a race, 130 PSI for smooth fast tracks or 120 PSI for the more bumpy ones...

alanbikehouston

The proper PSI is when the rim "drops" 15% of the width of the tire when you get on your bike. For a tire that measures 23c (most tires MARKED 23c measure at about 20c) 15% of drop is about 3mm. That amount of "drop" creates a significantly wider contact patch for better handling and braking, without the tire becoming "soft" enough to increase rolling resistance.

The gifted bike engineer Frank Berto of the REAL Schwinn company tested tires under a variety of weight loads to "chart" what combined load of rider plus bike yields a 15% drop.

His test data indicated that if the rider plus bike weighs 130 pounds, the correct PSI for a tire "marked" 23c (and measuring 20c) is 75 PSI. If the rider plus bike weigh 220 pounds, the correct PSI is 140 PSI (if the "safety" rating stamped on the tire allows 140 PSI).

The 3mm in drop is JUST enough sag that a buddy standing behind your rear wheel can detect it with his eyes when you get on the bike. If there is ZERO drop when you get on the bike, your PSI is too high. If the rim drops by a bunch (6mm or 9mm or more) your PSI is too low.

Mr. Berto also noted that on most bikes, about 55% of your weight is on the rear wheel. He suggested that riders can add 10% more PSI to the rear wheel to compensate for that. (So, instead of 75 PSI, go to 80 PSI and instead of 140 PSI, go to 155 PSI (if the safety rating permits).

Marge

100 psi and I check every time I go for a ride.(road bike) Now on my dump truck/hybrid
45-50 psi is good enough. Only check them once every 4-5 days.

alanbikehouston

I hope you can post the entire Michelin "rider's weight for correct PSI chart". Every good tire should be sold with such a chart attached.

Mr. Berto's chart indicates 116 PSI is correct for a guy weighing 185, on a 25 pound bike, IF the tire has a measured width of about 22c.

davismule

Ok... found it on their webstie:
https://two-wheels.michelin.com/2w/fr...111118&lang=EN

Medpilot

I’m glad this thread came up. My 23c Vittoria tires say 130psi min – 160psi max.

I’ve been riding with 140psi to stay in the lower ballpark range, but I’d like to run a little lower.

Any ideas why the manufacture would suggest such a “high” minimum?

woodcycl

I'm 5' 7" tall and weigh 170lbs. I have the old Trek 5200 running 23c. After about 15yrs of riding, what works best for me is a pressure between 120 and 130. Yes, it is a little high, but it works for me. Back when I was 140 to 145lbs (yes, about 10yrs ago ... uggh), I was running 110 to 120.

The ride is stiff on the bumpy roads, but I'm used to it and I like the low rolling resistance. And, no problems with flats, etc.

woodcycl

I have same rating on my Vittoria's (on my Mavic Kysrium elite rims) ... I was wonderfing about that too. But, I still run my usual 120 to 130.