I was looking closer at a set of wheels I bought from someone local and in the rim are 2 holes drilled. The holes are opposite each other and located in the middle. I believe I saw on a video that it was for water to drain and help dry the inside and to help the tire to grip the rocks we are crawling on. Not sure if that is right, so would love some input....I am also wondering does there need to be 2 holes and the size...these are about the size of the eraser on a pencil....??
The tires are glued to the rims....F.Y.I.
It's normal, let's air in/out as the tire conforms around the terrain. The number and size of the holes is all dependant on the performance you desire.
+1 wehan, the holes help the tires flex more instead of "bouncing" as much. I would recommend taping over the holes to run in water, you want to try to keep water out of the tires as much as you can. If you do submerge them, you should drill small holes (or cut small slits) in the tread of the tires to "spin and drain" them, and the foams will take days to dry-up unless you disassemble them to dry.
chop it up ... stitch it up ...It's ALIVE !!!
Thanks guys..! I was thinking along the same lines but not sure.