Random11

On pavement, I put 80 psi in my Marathon Plus tires. (Less when riding off-road.) Most BF participants would say that's too much, but I'm willing to take some heat from BF members to ride the pressure I like. Higher pressure does feel faster on the road.

urbanknight

Precisely why I go ahead and top it off before every ride. Besides, it's the only upper body workout I ever do.

50PlusCycling

That’s kind of like asking “What’s a good wine to go with this dish?” Each waiter will give you a different recommendation. The best option is what is embossed on the tire itself.

PeteHski

The OP was talking about rough roads, so probably not a great idea

PeteHski

All that gives you is a maximum pressure or a min-max range at best.

Robert7659

In the spring I simply inflate to maximum pressure indicated on the tire and just ride until September/October when it starts to feel too soft. The pump gauge confirms they are well below the minimum recommended pressure, but still ride ok, comfortable but a little sluggish. I have multiple bikes with different tire sizes and recommended pressures.

DaveSSS 

I can tell that a lot of posters aren't familiar with the latest tire and rim technology - wider hookless rims and 28-32mm tires that greatly improve the ride by transmitting far less vibration, all without increasing rolling resistance. I use the sram pressure calculator and find it's recommendations to work quite well. For my weight, my 28mm tires on 25mm IW rims use 52/55 psi. With 28/30mm tires and 23mm IW rims, I use 54/54 psi.

If you want a teeth rattling ride, add 15-20 psi and increase your rolling resistance at the same time.

I use a 30 year old Silca pump with a new Hirame pump head and a new, much larger diameter liquid filled gauge for greater accuracy. If you're losing air pressure with a presta valve, you have a lousy pump head or don't know how to use it. The pump head should not depress the plunger. The valve seals at the maximum pressure applied, so no pressure is lost when the head is removed. The air you hear gushing out is just in the hose. If you have Schrader valves, you are likely to lose air. Change to presta.

Also, digital gauges can be inaccurate, just like a mechanical gauge. They may have good repeatability, but without calibration, they may be highly inaccurate.
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Maelochs

Ride the bike. If you feel like you need more air, add some. If you feel like you have to much, let some out. If it feels okay, it is okay.

Move on.

KerryIrons

Here's the definitive calculator: https://www.renehersecycles.com/tire...re-calculator/

PeteHski

For its simplicity i.e. just weight and nominal tyre width, I think that's a pretty good starting point for most. The SRAM calculator is just more refined, taking account of more details like internal rim width. But the recommendations are very similar for my road bike.

smd4

The pavement around where I ride is pretty nice, so 140 psi feels great to me. Love the responsiveness and road feel of firm tires.

shelbyfv

I'm old enough to remember when we actually did 140psi or close to it. Some Vredestein model in 23. IIRC they advertised you could go to 150!

smd4

I'll take a pair! (Yes, I actually do pump up and ride my Veloflexes at 140 psi).

mschwett 

if you get a puncture, does the force of air through the hole launch you into near earth orbit? because that would be cool.

PeteHski

Me too, although I remember 110-120 psi being recommended. Roughly twice what I run with modern 30C GP5000S TR on my endurance bikes. Max allowed pressure is 73 psi on those.

mstateglfr 

Yeah, that tracks.

prj71

It's actually smartening it up.

Don't need all that crazy math and calculators to put air in the tires and ride a bike.

Find a pressure that you feel comfortable with, on the roads you ride, for the speed you like to go and just go ride.

PeteHski

There's nothing smart about ignoring the expert advice and just guessing your starting tyre pressure. You don't have to understand any of the "crazy maths" to use those simple calculators. They give you an educated starting point from which you can fine tune to your preference, but I understand if you find that a bit too complicated.

Jean_TX

That page says "This tire pressure calculator provides recommended tire pressure for Zipp wheels". So does that calculator apply if one is not using Zipp wheels (i.e. , not trying to go as fast as possible) ?

smd4

How did we ever function without on-line tire-pressure calculators?

Trakhak

That's how I do my taxes. I just decide how much of my money I think the IRS deserves. No need to overthink it.

PeteHski

It applies in general to any wheels. It's just that Zipp created the calculator, so it's kind of an advert.

prj71

It's not complicated, it's just dumb. Making the simple too complicated is the problem.

I tried the SRAM calculator above. What a joke. It recommended 60 lbs in my 700 x 32 tires for road riding. That's gravel tire pressure. It's more like 70-80 for my tires on the road.

Never ceases to amaze how people want to make the simple so complicated.

PeteHski

It appears that you just pumped them up as rock hard as possible.

79pmooney

Really this is pretty simple. The limits are - too soft. You pinch flat and maybe even damage your rim. Tire is too squishy to feel secure. Taking a corner too fast ,you could pull the bead off and blow the innertube and almost certainly crash. Too hard - the rim walls on the wheel give way with an explosion; maybe scraping the bike frame or your leg with jagged metal. Tire sidewall blows. Ride gets very hard and jarring. Cornering traction goes way down, especially on rougher roads.

Observe the cautions to both your tires and rims. Big tires can blow rim sidewalls off. Note the limits to your rims AND the recommended tire size. Reduce the pressure for larger tires. Too low is more of an issue of your weight, the roads (potholes and rocks will pinch flat tires and maybe dent rims) and your riding style.

And between those extremes you probably have about 50 psi to play with. My suggestion - add 10 psi to what you've got. Ride it for a week. Add another 10 psi. Another week. Keep doing this until you don't like the ride and go back to the last one. Fine tune from there.

The only place I have a hard rule is that I always go 5-6 pounds more in back. So for me a "90 psi" ride would be 93 in back and 87 in front. Some calculators show much greater differences front and rear. There's only one occasion where front tire pressure really matters. When you are braking as hard as you can to stay off the bumper of the car ahead that just slammed on their brakes and a pothole appears from under the car. At that moment, nearly all of your weight is in the front tire. Blowing out that tire or having the wheel fail at that instance could be really bad.

The grizzled old ex-racers back in the '70s always said 5 psi difference. I just did it because they said so. And now, half a century later, I still do and have never regretted it. (I do modify the 5 pounds if I am carrying load on the bike or I am using different size tires front and rear.. With heavy LowRider panniers, I may even have more pressure in front.)