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.
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
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.