The tires of my bicycle deflate within a couple of days. I have to pump every time before riding it. Is it true that if a bicycle is kept stationary(not used) for a day or so, then the chances of deflating are more than those when it is used regularly? I want a solution to the problem of pumping every time before using my cycle. How to get rid of deflation? I think the ambient temperature of the bicycle matters a lot in this case, but I don't know how. So, please give me a solution so that the tires don't deflate so frequently.
Tires deflating within a couple of days have a leak. If you don't ride your bike for a couple of weeks you may see some deflation but quicker than that you need to look for a leak in your tires.
Remove the inner tube and spray it with soap water. Pump up the tube a little, not a lot since you don't want to burst it, and check for bubbles. Repair any holes found.
Edit: also check the tire for sharp things to cause a new hole. Visually check the inside and outside of the tire. Then rub your fingers along the inside of the tire, be careful and do this slowly so you don't hurt yourself.
As far as avoiding pumping your tires up after storing the bike or not riding for a long time, you can either just deal with it or take the bike for a short ride every couple of days.
As a side note, I've heard storing a bike on carpet causes the deflation faster than other materials.
The loss of air pressure is due to the ambient pressure being lower than the pressure in the tires, and a path for with air can pass from inside the tube to outside the tube (commonly called a leak). There really are only two solutions:
Store the bicycle (or just the wheels) in a hyperbaric chamber. You could theoretically even inflate the tires this way, though they will look deflated while the chamber is pressurized.
Block the passage of air molecules from / to the tube. Also called repairing the leak.
As Doug mentions, you can use soapy water on the inner tube (not the tire) to find the leak. Don't forget to check the valve stem as this is where I find most slow leaks come from. You could even check the valve stem while the wheels are still on the bike.
When a tire deflates, it is because the air is escaping. Since air pressure in the tire is much higher than atmospheric (2 - 8 bar vs 1 bar for atmospheric) it is unlikely that changes in the weather / barometric pressure play a role. Similarly, temperature can play a minor role, but it would be on the order of a few % at most (pressure being lower on a really cold day).
There are three main paths for air to escape:
- the valve. Depending on the type of valve you have, it may be possible that you can replace (parts of) it - but it's hardly ever worth it
- a small puncture. If you drove over a sharp object you might have a tiny hole in your tire - but realistically even very small holes would cause the tire to deflate in a matter of hours, not days
- the rubber of the tire. This is where I put my money. Rubber in general is slightly porous - that is, air can "sneak out". Different kinds of rubber have greater or lesser porosity - some butyl rubbers are particularly hermetic, some natural rubbers quite porous. As a tire ages, it can become more porous.
You could take the tube out, inflate it in a bucket of water with a few drops of soap. Wait a little while - see where bubbles appear. My bet is "all over the tube". That would point to case #3, in which case the only remedy I know is to buy new tubes.
Another option (admittedly not a life hack) is to add tyre/tire sealant to your tube. This is a white liquid latex-based goop which goes in after you remove the valve core, and then sits inside the tube. If you get a puncture while riding the sealant is supposed to bubble out the hole for a few seconds, then harden and seal the leak.
One of the well known brands is Stans, http://www.notubes.com/Stans-Tire-Sealant-Quart-P51.aspx and while its intended for tubeless tyres, does okay in tubes too. Note it only stays effective for months, then you need to add more. Also, this stuff is sometimes called "stans jizz" so just call it "sealant" if you don't want a ribbing from, your riding mates.
Otherwise replace your tubes, they're only a couple bucks each, and the dead tubes/valves can be used for many other things.