What inner tube size to get for my road bike? I want to get some spare inner tubes for my new road bike, but I'm unsure what size to get. On my tire it says the size is 700 x 25c and I know that 25 is the max width of the inner tube. So should I get 700x20-25c or 700x25-32c? I'm guessing 700x20-25c would be the safer option, correct?
As long as it is in the range you are good.  You can even cheat outside the stated range a bit.  Too big and you can fold.  Too small and you stretch.  If it is spare you are going to carry on the bike then the smaller.