davew":27118g7l said:I use Schwalbe tubes that have a threaded valve and locking nut so the valve can be "locked" to the rim.
There are 2 schools of thought on using lockrings on tubes. Tires can slip under braking and (not so much) acceleration forces, especially offroad and/or under low pressure. Without the lockring the valve will (usually) slip into the rim when this happens. No biggie. Just pop the tire off and re-seat everything.. With the lockring on, if the tire slips, the valve gets ripped off at the base. I'll live with the former, and toss the lockrings in the trash bin when I pull a new tube from the box.
The effect is so common on speedway bikes they often would put the valve through the right sidewall of the tire at a 90 deg. angle and when (not if) the tire slips it doesn't affect anything, other than acceleration.
Look close. No valve stem in the rear rim.