Thread: Low-budget/T-Bucket Pickup

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They were VW size radials on steel wheels. Brakes were very heavy 39 Lincoln drums. All this weight created two very powerful gyroscopes. The axle itself was a 39-40 Ford I-beam and was pretty light compare to the wheels, tires and brakes.

I think what I was experiencing is known as axle tramp, where one side of a straight axle affects the other side through gyroscopic precession. The tire imbalance caused a little instability in the tires and this was amplified by the heavy wheels and brakes. Essentially, the two gyroscopes started fighting each other to remain upright. At just the right speed, the axle would bounce from the left wheel to the right wheel(not a wobble or shimmy, but a bounce) and could become pretty violent if you stayed at the "trigger" speed. Once I learned what the speed was (about 50 MPH in my case), I just didn't drive there. I either stayed under it or drove through it. As long as the tires were round and well balanced, it really wasn't that noticeable and the car drove very good, even at speeds over triple digits (closed course, insane driver, don't try this at home kids).

At the T-Bucket Nationals, I got to talk to a lot of bucket drivers and found out that many T's experience this type of bounce from time to time.