Many of you who have followed our videos and used our Rail Rider(R) process have enjoyed great success with this wonderful alignment process. We feel we have worked hard to create a excellent and repeatable way to align a Pinewood Derby Car even without a test track. (Ah: the unknown of Pinewood Derby). But we do get asked frequently what the best way to align a Pinewood Derby Car is if all 4 wheels have to touch the track, and again, we recommend the Rail Rider. Now it is a little trickier to do but it can still be done and is a LOT faster than a straight on alignment. This is what we call “The Ultimate 4 Wheel Rail Rider”
Start off with your body block drilled square with all 4 wheels touching (The Pro Body Jig is BEST for this). Next you will align the rear of the car correctly establishing zero-toe (this is explained in the video Pro Rail Rider Tool Video). Now for the tricky part, you will want to run 2.5 deg. of axle bend in the front on both axles, BUT the dominant wheel (steering wheel) will be cambered positive (top tilting out) and the non-dominant wheel (the wheel along for the ride) will be cambered negative (top tilted in). The non Dominant wheel should just lightly touch the track, almost floating, not resting on the axle, this is where the tricky part comes in and will take some working with. We recommend bending this axle 2.5 deg to start with, but you may need to take a small amount of bend out after test fitting or you can use small pieces of wax paper or foil to shim the axle in the axle hole to get it right.
The final goal is with the wheels pushed in against the body for all 4 wheels to touch the track, BUT as the car goes down the track and the dominant wheel makes contact with the guide rail, the wheel is pushed out towards the axle head, the front of the car will slightly rise and unload or raise the non-dominant wheel off of the race track and effectively act as a 3 wheel car and reduce your cars friction by 25%. Now do not be discouraging if you can not get it the raise at first and run out of time, because by just using a Rail Rider Alignment with all 4 wheels touching, your car will have much more control preventing the dreaded “Speed Wobbles” and making for faster and smoother runs.
Good Luck Racer