Originally Posted by
ka0use
could one ride a bike on the moon's surface?
Yes, certainly. I'm not sure though what "The Rules" say about wearing a spacesuit while riding a bike.
Originally Posted by
ka0use
is space absolute zero?
No. Space is vacuum. Vacuum has no temperature. The idea about things exposed to space necessarily "freezing" is a silly urban legend. Vacuum is in fact a perfect insulator, i.e. it completely stops any direct heat transfer losses and any convective heat losses.
In such environment thermal radiation becomes the dominant heat transfer method, meaning that things heat up relatively quickly in direct sunlight and cool down relatively quickly in the shade.
Originally Posted by
ka0use
if so, would you have to have all lubed parts degreased to prevent the lubes from freezing and preventing riding?
It will freeze if you let it freeze (by allowing it to lose all its heat through radiation), but it is up to you. With the same degree of success you can let it overheat and burn up instead of freezing.
I'd say that when it comes to lubricants, the primary concern would be the pressure, not the temperature. In non-pressurised environment liquids boil and evaporate much faster, which is what will happen to "ordinary" lubricants.
Originally Posted by
ka0use
what about the air in the tires? would you have to use solid tires?
No. You'll simply have to adjust the pressure to compensate for the lack of external atmospheric counter-pressure. Also, rubber tires have to be kept in certain range of operating temperatures. Outside of that range rubber will either crack or burn.