My possibly incorrect logic - the tube is anchored to the rim at one place, the valve stem. The tube, by design, is very flexible. If the tire moves relative to the rim, it will try to take the tube with it, tearing the valve stem out, since it can't move. So a security bolt is added, to try and anchor the tire to the rim. I can see some argument that having the security bolt 180 degrees opposite the valve stem may not be optimum. So the security bolt is placed in one of the two holes that are closest together, with the valve in the other hole. That distance is the same whether it is valve first, or security bolt first. Here is where I get confused, can't picture things in my mind. If the bike is at a standstill, and you are launching the bike, as if at a drag strip, the rim wants to immediately start turning from the force of the motor, through the drive train. But the tire does not want to move, from the friction with the pavement. That is one direction of movement between the tire and rim. But when the bike is rolling down the road at 60 MPH, and you slam on the rear brake in a panic stop (assuming a brake that can lock up the wheel), the rim stops, but the tire wants to keep moving (or skids along the pavement, either way, a force wanting to move it relative to the rim). In both scenarios, is the tire trying to move relative to the rim in the same relative direction, or in the opposite relative direction??? I can't wrap my mind around the "frame of reference".