Bicycle Mechanics - need help with pumping my tires.

I got a tire pump with a gauge for me and my girlfreinds mountain bikes. when i pump the air into the bikes the gauge does not go up intill i am halfway done. then it will go up to 20 but by the time it is at *20* psi the tire will be hard as a rock. i pumped it to *40* psi and it just feels like it will explode if i get into it and ride.

my bike tires read pump to a min of 35 to 50 psi max. but like i said at 20 psi it seems hard as a rock.

the bikes both have schrader valves.
http://www.geocities.com/cyqlist/schrader1.jpg

i then bought a 3 dollar pen pressure reader but it does not work. i dont understand how it is suppose to work. it says

*press gauge firmly onto the valve stem and read psi on indicator* but i dont see any line or anything going to any number.

then it say's to inflate to recommended pressure.... ok

this is the pen i bought
http://www.slime.com/product_201_20-...e_(20042).html


now even tho the gauge on my bike pump say's 20 psi and it is hard as a rock is it fine to keep pumping it to 35-40 psi? or should i just leave it at 20?

i dont even know if the pump is working with the gauge monitor.

I don't know what to tell you about the pump, but the pen guage works by pressing the open end (top of the unit in the picture) on to the valve and then reading the number on the white shaft that pops out of the other end. The number closest to the pen body is the pressure. the end of the silver pen body is the indicator line.

the white thing does not pop out tho.

maybe it does not work for my valve??

it take more pumping to put 30psi in than it does said 90 psi because of volume the size inside of a tire, wider the tire more air to take up the space as with the narrow one less space but more pressure. what kind of pump are you using ? small pump more stoke , bigger pump (floor pump ) less numbers of stokes.

i am using a floor pump. it was 19.99 at walmart. dont know the brand i ripped the tag off

I bought a Bell floor pump from Walmart. The gauge worked fine, but the pump started leaking air at about 40 psi and wouldn't go above 80 psi no matter how much I pumped. (They also had Schwinn floor pumps, but of the half-dozen or so I examined in the store, all of the gauges showed different readings and none read zero.) So I got a refund for the Bell pump and bought a Specialized Air Tool Comp floor pump from a bike shop. It was more expensive ($40) but the gauge works perfectly and I've had no trouble at all with pressures of 100 psi or greater. I suggest you get a better quality pump.

Go try that pressure gauge on a car. When you first use it some air will escape always so you will hear a hiss.

Cheap Wal-mart pumps and their gauges are not the best and I never rely on them.

For a list of reasons more exhaustive than this, I simply don't buy things from WalMart. My reason primarily 'cause i can't stand going there. Bike stuff I take far too seriously and know I will get good quality through a bike shop and brands that are sold at bike shops. If your bike is a mountain bike, the tires shouldn't be hard as rock. (Fat tires on mountain bikes are supposed to be part of what cushions the ride and they can't do that if they are hard as rock.) I'd return your pump and visit your local bike shop.

A benefit to visiting a "bike shop" instead of a mega-store is that most bike shops are still local businesses and you can support your local economy in ways that WalMart just doesn't do.