simple question re:tire pressure

new2bikes said:

Hello. I've been given conflicting advice about tire pressure and would like some clarification. On the outside of the tire (road bike), it says to inflate to 120 psi. I've been told by some that that is the maximum pressure and I should actually inflate to a lesser degree to avoid a harsh ride and to avoid a blow out - especially as the weather warms up. I've also been told to follow the recommended tire pressure as indicated on the tire. I'd appreciate any comments. Thanks.

I fill 120 psi , don't forget when you take out your pump head from the valve of tire some air is running out.The best performence of a tire is the manufacture's recommendation.I'm sure its not the max. psi.

Gadi

new2bikes said:

Hello. I've been given conflicting advice about tire pressure and would like some clarification. On the outside of the tire (road bike), it says to inflate to 120 psi. I've been told by some that that is the maximum pressure and I should actually inflate to a lesser degree to avoid a harsh ride and to avoid a blow out - especially as the weather warms up. I've also been told to follow the recommended tire pressure as indicated on the tire. I'd appreciate any comments. Thanks.

The 120 psi on the side of your tire is probably the max rated pressure. Does it say "max Pressure"? Some tires, like Michelin Pro Race, put the "pressure range" on the sidewall, ie 87-116 psi. The Conti's GP 3000s that I use list 110 psi as recommended, 120 psi maximum on the box, while sidewall has only the max rating.

Correct pressure for you depends on your weight and the roll surfaces you ride on. The right pressure will give you a better ride, more grip, lower rolling resistance, and fewer cuts and punctures. Various tests on real roads (not smooth track surfaces) have shown that lowest rolling resistance is around 100 psi, unless you are a heavyweight rider. I'm 178 lbs, and run 100 front, 105 rear.

Thanks. The tires (650's) are Bontrager Race Lites - the ones that came with my bike. They don't say "Max Pressure" - just "Inflate to 120 psi," and the Trek manual says to "inflate the tires to the air pressure recommended on the tire sidewalls," so that's what I've been doing. I did notice that if I inflated the tires to a lower psi that the ride seemed "softer" (more grip?). I suppose that gives me more control, but just a few rides after lowering the psi (to about 110), I got my first flat. Coincidence probably. I'm light-weight - 111 lbs. so I'm certainly not weighing down the tires. Trial and error? Or just do as the Trek manual says?

new2bikes said:

Thanks. The tires (650's) are Bontrager Race Lites - the ones that came with my bike. They don't say "Max Pressure" - just "Inflate to 120 psi," and the Trek manual says to "inflate the tires to the air pressure recommended on the tire sidewalls," so that's what I've been doing. I did notice that if I inflated the tires to a lower psi that the ride seemed "softer" (more grip?). I suppose that gives me more control, but just a few rides after lowering the psi (to about 110), I got my first flat. Coincidence probably. I'm light-weight - 111 lbs. so I'm certainly not weighing down the tires. Trial and error? Or just do as the Trek manual says?

I'll use a higher pressure if I'm going to be attempting a personal best or doing some intervals. However, if I'm just out for a regular training ride or recovery ride I'll not pump them up all the way just for comfort's sake.

I have a pair of Specialized Turbo Sports that have 130 PSI on the side. I've never pumped them up that high. 120 seems like more than enough pressure to me. 105 - 110 PSI seems about right for most rides. I weigh 245.

I haven't had a flat in over a year, except recently when I put a set of tires on different rims incorrectly and pumped them up only to hear a mind boggling explosion! That was attributed to user error! :o

new2bikes said:

Thanks. The tires (650's) are Bontrager Race Lites - the ones that came with my bike. They don't say "Max Pressure" - just "Inflate to 120 psi," and the Trek manual says to "inflate the tires to the air pressure recommended on the tire sidewalls," so that's what I've been doing. I did notice that if I inflated the tires to a lower psi that the ride seemed "softer" (more grip?). I suppose that gives me more control, but just a few rides after lowering the psi (to about 110), I got my first flat. Coincidence probably. I'm light-weight - 111 lbs. so I'm certainly not weighing down the tires. Trial and error? Or just do as the Trek manual says?

Yes, it's a coincidence, unless you hit a pothole and got a pinch (snakebite) flat.

At 111 lbs, you certainly don't need the same kind of pressures that I run at 178 lbs.
If your tires are 650 x 23 mm, suggest you try 85 front, 90 psi rear....that's plenty for your weight. Believe you'll find ride and grip is better, rolling resistance is lower on anything but the smoothest roads, and fewer cuts/punctures as well.

Don't know why Trek would recommend inflating to max pressure without even knowing your weight. Perhaps they figure their owners aren't going to check their tires regularly, and might as well inflate to the max when they get near a pump.

Thanks, everyone. I'll experiment with different pressures and see which ones give me the best ride. I appreciate your clear detailed responses.