i've just got some new wheels and i want to ghetto tubeless them, but the rims are very deep so i need a tube with a long valve stem. i only want to used schrader valves, preferably ones like the continental tubes where the thread on the the valve continues all the way down and there is a lockring to keep the valve in place (similar to presta valves).

so…20" tube with long valve stem & lockring.

do they exist? can anyone point some out at CRC or somewhere else? Thanks!

Here's the ticket

http://www.chainreactioncycles.com/Models.aspx?ModelID=24639

cheers dude!