Hey biker chick?....why not just carry an extra cartridge? I always carry 1 cartridge in the housing and an extra one on the side. If I'm riding alone over very long distance - I pack 2 more in the camelback, that way I've got Plenty just in case!
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand, strawberries in the other, body thoroughly used up, totally worn out and screaming: "Yeah Baby! What a Ride!"