On Jun 11, 10:25*pm, "mary" wrote:
Is it just me or do tubes with presta valves have to be filled up more
often? *It seems like once a week I have to top off the air in the tubes..
Just wondering. Oh and before you ask, yes I make sure the valve is closed
all of the way after filling.

The valve is the weakest link in any tube but it isn't the only place
air escapes. You lose pressure through the tube wall itself as well so
no matter how tightly you seat the valve you're still going to need to
get out the pump periodically. That said, needing to pump up the tires
once a week seems pretty much usual to me.

Regards,
Bob Hunt