Yes, if a cyclist is stranded on the side of the road I would give them my last anything. But, on a recent ride a girl flatted about 1 mile into an organized metric century, with no tube, and since I knew there was sag support I made her wait for the sag vehicle rather than giving up my own supplies since she should have been better prepared, and probably flatted immediatly by failing to inflate her tires properly before the ride.