leak down
 

I got a cheap, used bike a few weeks ago and just ride on weekends. But I air it up to 45psi before a ride and by the next week it is down to 25-30psi.

Is it normal for bike tires to lose pressure fairly quick or should a leak be suspected?

How often do you have to add air?

thanks

It's normal for tires to bleed air slowly. The rate depends on the width and pressure, with narrow high pressure tires being faster than fat mtb tires. Your loss may be at the high end of the normal range. It's possible that you have a pin hole leak, or possibly it's leaking through a loose valve.

If you can live with it, just buy yourself a basic ($10-15) floor pump to keep your tires topped off. If you don't want to live with it you'll still need a pump because, even in the best of circumstances, you'll still need to top tires off every 2-3 weeks.

it depends on your setup, my commuter runs skinny tires at high pressure ~100psi and those tires get aired up once a week to maintain pressure. My mountain bike runs significantly lower pressure ~35-45 psi and I rarely air those up, unless I have a flat.

It may be just normal leakage, you could just keep airing it up every week, or if that is too much trouble change the tube. Its an easy change depending on how old your tires are.

You either have a slow leak in the tubes or you've got some extra thin tubes which are more porous. In either case, get yourself some new tubes of at least normal weight and you shouldn't have to pump up your tires more than once a month or so.

Those who use narrow, high-pressure tires (~ 100 psi or more) need to pump them up much more often, especially since the narrower tubes are often made of thinner rubber as well (for decreased rolling resistance). But there's no need for such thin tubes on the wider low-pressure tires you have.

If they are both losing the same amount of air then it's the normal leakage for those tubes. If one is significantly lower than the other then you've got a leaky valve or a pinhole in the lower tube. It COULD be two identical pinholes but the chances of that are somewhere between slim and nil.

Pull the tube out, inflate it to more than normal size, submerge it in water, and look for air bubbles. Patch it.

My rear tire had a tiny hole that would slowly leak; it would be fine for a ride but within a couple days it would get down to a low PSI but not completely flat. It was impossible for me to find by just feeling for it without water.

Spend about $30 and get a good pump. (Topeak Joe Blow Sport is one good pump.)

Good point....they do lose about the same amount per tire. It has 26" tires.


I don't have a frame nor floor pump but use an air compressor. I just plug it in until it hits 50psi or so then air up the tire until the air pressure tapers off.

Doesn't seem like a tone of work to do every week or so.

Ok, so I went to check on my mountain bike the other day to check out and make sure this foot pump works since I may be getting a Trek 1200 today and the tires were full of air and they havent been touched in at least a year. But my Montgomery Ward 26" road tires both leaked down the same psi. So were they both punctured or do road bike tires differ from MTB in that regard.

thx