Newbie question about inflating tires
 

I bought a used road bike (07 Trek 2.1) with original tires. The tire says 120 PSI max. pressure. When I tried to pump it with a new hand pump, it went as far as 75 to 80 and couldn't get it inflated anymore. I mean I was pumping a lot and pretty hard, short of killing myself. And I didn't want to damage the tires too. Is this the right pressure? Or should I try to try to get it closer to 120, if so, how?

Thanks!

You gota get a Floor Pump.
Pump them up everyday before you ride.

Floor pumps are manditory. Hand pumps are for in a pinch. A good floor pump with a guage that goes to 160 is all you need. JensonUSA an advertiser here has a bunch priced from 20 to 40, these are among the best. LBS might have good ones too.

+1 on the floor pump. I only use my hand pump to inflate my tires up after i flat so i can get back home.

I like the Joeblow Sport. Expensive, but it's good - the kind they'd use in the shop.

Floor pump yes!

Also. The number on the tire is 1/2 the pressure that it takes to blow the tire off of the rim. Here's a good article on tire pressure. Note that manufacturers agree with the priciple. http://www.adventurecycling.org/reso...SIRX_Heine.pdf

You can't give an exact number like that. Each tire/rim combo is different. There's no way the manufacture can now what the exact blowoff pressure is. It's more accurate to say that it is quite likely much higher than what is printed on the sidewall. For road tyres like the OP has, riding on the road there's almost never any reason to go above ~130psi.

3/4 down this page is a table that shows pressure needed depending on the tire size and your weight http://www.sheldonbrown.com/tires.html

Also, there are road pumps and MTB pumps. Road pumps are higher pressure but lower volume. MTB pumps are higher volume but lower pressure. MTB pumps are not designed to get a tire to higher pressures.

Thanks for all the advice.

I also used a floor pump but I could only go as far as 80 PSI. I pumped another 50 times but it won't go pass 80 PSI. (Max PSI is 120 for the tire). I am not trying to find the optimum air pressure. I am just wondering how come I couldn't pump it up to 120?? Did I reach the limit of the tire already?

I recommend two 120v air compressors. I have both of the compressors indicated below, and they work great, especially for old guys like me who want to save their energy for bike riding, not pumping up tires. They're not very expensive either.

http://www.amazon.com/InterDynamics-...624229&sr=8-11

http://www.amazon.com/Black-Decker-A...9&sr=8-1-fkmr0

What brand of floor pump? Cheap ones can fail at less than 70psi (I've seen it happen). My Blackburn pump goes to 110psi easily and reliably, and the Park "Home Mechanic" pump says 160psi max.

Also, what are you using for a gauge?

I can second this from my own experience. A brand-new, $20 Bell floor pump I tried last year couldn't get above about 80 psi no matter how much I tried. By that point, I could feel air blowing up at me along the pump handle on each downstroke. I took it back and got a Specialized Air Tool Comp floor pump for a little over twice that price and it works great. Normally I keep my tires at 95 psi, but with this pump I've had them up to 115 with no trouble at all. I don't know what the practical limit would be, but the built-in gauge goes to 160 and it wouldn't surprise me a bit if it really can go that high, based on the performance and reliability I've gotten from it in the past year.

No, you reached the limit of the pump, if it's not in a state of disrepair and the pump head is properly attached.

I think you guys are right. Mine is a $25 Avenir Air Source Sport pump from Dick's. It looks decent with an air pressure gauge and plastic padded handle and stand, etc. Too bad, I think I threw away the "wrapping" paper already. I guess I have to go to a bike shop to pick another one up.

Thanks!

+10 Crappy pump. Take it to a bike shop and they will probably inflate it for free for you. Then replace the pump with something better. Also, do you have a good tire pressure gauge?

You need a good road bike pump with a built-in gauge. Fully inflate your tires before each ride. I weigh 165 and use 118 psi in the rear tire and 110 psi in the front.

Al

The Topeak Road Morph gets my tires up to 120 with an acceptable amount of effort. That said, I use my floor pump when I'm at home (Park PFP-3).

I bought the same Avenir pump at Canadian Tire (labeled "Raleigh") and it had no problem going up above 100 psi. It sounds like yours might have a leaky hose or the valve may have been improperly fastened to the valve stem. Or it might be defective. Take it to Dick's and see if they can find anything wrong with it... or maybe they will just send it back to the distributor to see if it will be replaced.

a Silca Pista floor pump is a must. also look into CO2.

One of the most common problems that I see with people pumping up their tires is the failure to bottom the piston in the pump. They feel resistance as the slug of air in the cylinder compresses and then think that they have pushed air into the tube so they pull the handle up and try again. But they are getting no where because they are just recompressing the same slug of air each time.

You have to push down on the pump piston until the piston bottoms out. It gets harder to put air in as you get higher in pressure but you still have to get the piston to the bottom of the pump cylinder or the air doesn't go into the tube. If the air doesn't go in, you might as well use the pump as an upper body Stairmaster. Hey, that gives me an idea:thumb:

And use your weight as much as possible to push the plunger. And, go slow and in control (many people think that pumping fast is easier but it isn't).

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Overkill for most people. Unless you are light, pumping up a bicycle tire with a floor pump is easy and doesn't take much effort. If you need to "save energy", you are likely doing it wrong.

Thank you for all the advice. I finally got a blackburn tower II for $40.00 Problem basically solved. I could go up to 110 and 120 PSI now. Yes, I need push it all the way in the tire to "seal" the air.

The only problem is that, when I release the pump from the tire at the end, I always lose some air. Not sure how to fix it?

Most of the air that you hear escaping when you pull the pump chuck off is from the hose and the pump. The inner tube valve seals immediately, try to pull it straight off the valve stem.

Al

If the valve is a presta, all of the air comes from the pump hose;)