Hi, I'm thinking of putting tubes in. I want to air down for beach running but i dont want to spin the tires. I mean that when Im on the sand Ive been told to lower pressure to 12 to 15 lbs. Seems kinda low. They tell me its because of the type of sand on the beach. Dont want to get stuck. I can air up after but the only air requires driving about a mile or so on the road. Guess I could get a compressor or use an air tank. Thought it would be good idea to install tubes. Anybody do this. Thanks for any advise. Robt.