Reader Magnus came up with a great hack to help keep liquid in your water bottle a liquid during freezing temps. He even did his own experiment to prove the effectiveness of the hack. Hmmm, maybe I should create a shield for my whole bike! Take it away Magnus . . .
This is my little hack . . .
I cut the top of a PET soda bottle and mounted my bottle cage inside. But why? I live in Sweden and the temperatures are not the most favorable during a significant period of the year and cold temperatures combined with the drag from the speed of cycling makes the liquid in the water bottle go very cold very quickly.
This "windshield" makes the liquid hold the temperature better. A test I made with hot water over a 1 hour ride showed the protected bottle was 10 deg Celcius warmer after the ride then the unprotected bottle. Another nice side effect is that you don't get as much dirt from the road on the bottle.
More, in Swedish, here.