Loss of tire pressure

acurno

How much pressure would you lose from the tires with a typical 2-3 hour ride? I always check my tires before I head out and they always seem to be around the 80psi mark before I pump them to 120. Where does the pressure loss occur?
When I take off the pump there's always a big pop due to the high pressure am I losing air here? Would of thought there should be minimal loss from week to week.

TheBlaaMan

Something is wrong there...........minimal loss would be the norm, perhaps 10-psi per week, or something like that. Perhaps try reading the pressure at the time ofd pumping by putting the gauge/pump back on immediately and seeing if either the 'pop' that you are getting is actuall loosing more than you think, or (more likely) the gauge is mis-reading initially when you are pumping.

Dubba

Probably about the same due to the air escaping when taking the pump off and when leaving some air slip before re-inflating.

I always re-infalte to 120psi before each spin, if only for peace of mind.

No punctures in around a year but having said that now looking forward to pop, pop, pop....:rolleyes:

saa

Hey what pumps do you use, bought a 15 euro basic one without a gauge, doh doh doh.
It just doesnt seem to get the tyre up to a decent pressure.

So any recommendations?
something like this?
http://www.argos.ie/static/Product/partNumber/3334931/Trail/searchtext%3EBIKE+PUMP.htm

Probably would get the eqiv in a bike shop for around 30, hopefully that isnt a false economy

cython

saa wrote: »

Hey what pumps do you use, bought a 15 euro basic one without a gauge, doh doh doh.
It just doesnt seem to get the tyre up to a decent pressure.

So any recommendations?
something like this?
http://www.argos.ie/static/Product/partNumber/3334931/Trail/searchtext%3EBIKE+PUMP.htm

Probably would get the eqiv in a bike shop for around 30, hopefully that isnt a false economy

I would go for something like this, or one of the Topeak Joe Blow range ahead of what you have linked. I currently have the entry level Topeak, the Max II, and it was well worth the price. My biggest gripe with what you linked would be that it looks a bit unsteady with that tripod type base, whereas either of the ones linked are attached to a platform that you can stand on to give yourself a sturdier/more secure pump when you want to get that last few PSI into the tyre. With that in mind, there are plenty of other options out there, but I linked those 2 specifically as I have used one, and seen the other recommended on here.

EDIT: CRC was down when I posted before, but this would be a step up in the topeak range from what I have for only a little above the 30 mark

acurno

I've a decent pump so I don't think a faulty gauge is the problem. Is that 'pop' that occurs once you take the pump off the valve normal? I'm assuming it is, seeing as it's just equalization of pressure between the tube valve and the pump.

cython

acurno wrote: »

I've a decent pump so I don't think a faulty gauge is the problem. Is that 'pop' that occurs once you take the pump off the valve normal? I'm assuming it is, seeing as it's just equalization of pressure between the tube valve and the pump.

Some pop/hiss would be normal, certainly. The reason behind this being that when you have the pump head secured, you should have an environment of similar pressure inside and outside the valve, with the pressure outside being higher on the pump stroke, to force air on. Then when you remove the head, the pressure trapped between the valve stem and the head escapes, causing this noise, and the valve closes. A tiny amount of air may be lost as the valve closes, but assuming that you have not had to fight with the head to remove it, and caused a load of hissing, it should not cause a significant decrease.