bychosis wrote:Normal, but not sure about the hot weather reason, happens in winter too.
greyhoundtom wrote:They are quite correct, tyres do loose pressure as air molecules filter through the rubber of the inner tube.
The higher the pressure the faster the air loss.
Gases expand when heated = pressure is increased even more = faster loss due to above. Movement of the tube whilst cycling probably helps the process (where "helps" means quite the opposite from a rider's perspective).
Diffusion still occurs in winter, just not as quickly (where "quickly" = probably rather slowly in the grand scheme of things).
A leaky valve is just a bigger opening for inner and outer pressures to try and equalize through. Same principles should apply.