224 also used that same tubing on thier 2002 robot, you could try finding someone on thier team to answer what it is.
http://www.geocities.com/firstpsga/home.htm is thier website.
From what I saw those worked amazingly well on the soccer balls. I would check with mcmaster
www.mcmaster.com or check with msc.
edit: Quickly looking around mcmaster I found these,
part #'s 6567K32, 3044K195, there are many others in the round belts section of power transmission. I'm sure someone from a team who has used these before could give you the place and part number. There is also this interesting material that is all peiced together so you can get very nice connections in any length you want, # 2243K12