Tire Pressure

[Michelle T]

I'm 4'10" and weigh about 100 pounds. I'm going to buy a bike with tires that will take 120 psi. I've heard that lighter riders don't need and can be uncomfortable with the maximum tire pressure. How do I know what tire pressure is right for me?

[indysteel]

Just experiment. I'm 120 and ride at 100 psi on tires that can hold up to 120. I'd start with 90 psi if I were you and see how that feels.

[Xrayted]

Never go to max pressure on a tire, bike, car or otherwise. That is the upper limit. I would go, in your case, about 20lbs less than max to start. Get on it, see how it feels and how it LOOKS. Have someone look for you from the side as you go by. If it is compressing too much, put a little in. If it seems hard and you're feeling the road too much, taking into account what kind of frame/seat you have, then take a bit out. The biggest thing is to find a pressure that isn't harder than needed, so soft it won't give you a pinch flat and check the pressure at least twice a week depending on how much/how far you ride normally. If you only ride on weekends, then absolutely, check it everytime you ride. If you ride to work everyday, then every other day give it a quick check.

I just hate seeing someone riding around on 1/2 the air needed, almost on the rim. The rest of the air must be lodged between their ears.

[Dogmama]

I'm 118 pounds & I've always run on 120 pounds of pressure (20 years of cycling.) I use Continental tires. I notice more rolling resistance at less PSI.

[indysteel]

On the often rough roads we have in Indiana, I'm willing to have some extra rolling resistance if it makes for a more comfortable ride.

[Catrin]

On the often rough roads we have in Indiana, I'm willing to have some extra rolling resistance if it makes for a more comfortable ride.

Hmmm, I am 138 pounds and have kept my Trek's psi at 110. I am wondering if I should drop that to 100 and see if the ride is a little more comfy on my country roads? With my weight would 90 pounds be too low?

[Thorn]

I'll join the "never run max pressure" chorus....because (hrrmph) it is right

Seriously. If you won't believe Sheldon Brown, try the guys over ad Road Bike Rider.

You want your tires to have enough pressure to avoid pinch flats and no more. For most riders (and they're basing their logic on avg male weights) 90-95 is plenty.

If you run a high pressure, your bike will bounce over little bumps (oh, like say chip seal). You get the impression that you're moving, but, in reality, your wasting energy bouncing up and down instead of rolling forward.

If you run a lower pressure, your tire can deform around those small bumps. You don't lose energy bouncing up and down and you get the side benefit of a more comfortable ride.

The Road Bike Rider guys will also say you're less prone to puncture flats if your tires can deflect around some of the road debris. If the tire cannot deflect, the glass will go through the casing.

[tctrek]

Hmmm... riding at lower pressure seems to make sense. I've always done 100-110 psi, but I am soooooooo flat prone. True the choices of where I have to ride suck and I end up on roads that have lots of crap on the side. But I ride with DH most of the time and I am always the one with the flat. I might try the 90-95 psi and see if I could ride a few weeks without a flat!

[Dogmama]

Hmmm... riding at lower pressure seems to make sense. I've always done 100-110 psi, but I am soooooooo flat prone. True the choices of where I have to ride suck and I end up on roads that have lots of crap on the side. But I ride with DH most of the time and I am always the one with the flat. I might try the 90-95 psi and see if I could ride a few weeks without a flat!

I also got to thinking - it might make a difference depending on the brand of tire. I ride Conti's and they seem to have a rather soft rubber in contrast to, say, Michelins. So, maybe my 120PSI is similar to a 100PSI Michelin in terms of comfort and handle-ability...? But, I'm probably going to lower my PSI because the roads are hot & heat increases tire pressure.

[Bike Goddess]

I've been riding 100PSI on any tire I put on my bike. I seldom have flats. When I do, I have 2 new tubes in my seat bag along with my bike tools. Usually I give my flat tire to a friend who will use it on his rides. I'm too lazy to fix a tube.

I do suggest that you always carry 2 tubes with you. Also, if you put "baby powder" on them, it will make it easier to put on the rim.