Square Wheels (Episode)

=Episode Cast=
 * Jamie Hyneman - Host
 * Adam Savage - Host
 * Tori Belleci - Host
 * Kari Byron - Host
 * Grant Imahara - Host
 * Robert Lee - Narrator (voice)

=The Myths=

A vehicle fitted with square wheels can provide a smooth ride if driven fast enough.
Verdict - Plausible

Notes - Adam and Jamie designed a set of square wheels to support the weight of a pickup truck, then cut the treads off a set of tires and fitted them on. They set up a test course, using a heavy-duty pickup equipped with vibration sensors, and drove a control run (using round wheels) at speeds up to 60mph. When the square wheels were mounted, the ride was very rough at first but began to smooth out as the speed was increased. However, one wheel fell off after only a few seconds when its bolts snapped.

For small-scale testing of other wheel orientations, Adam and Jamie returned to the shop and built a cart to run on a treadmill. They found that if two opposite-corner wheels were turned 45 degrees out of phase with the others, the cart achieved a balance of smoothness and stability. A full-scale test at almost 20mph caused the tire treads and brake pads to come off the wheels. Despite the mechanical failures, they classified the myth as plausible, based on the sensor readouts and their own sensations.

Square wheels can give an advantage in hill-climbing when compared to round ones.
Verdict - Busted

Notes - Adam and Jamie set up a dirt track consisting of a straight stretch leading to a steep uphill run. They believed that the square wheels might reduce pressure on the soft dirt and/or allow the car to dig in and get better traction. However, the truck climbed the same distance up the hill with either round or square wheels, leading them to judge this myth as busted.

Date Night Car


Inspired by a scene in the film Date Night, in which a taxicab and sports sedan stuck together by their front bumpers perform a series of maneuvers in city streets. The Build Team obtained two cars similar to those used in the scene, tore off their front bumpers, and built a hitch to hold them together nose-to-nose. they tested the cars at 40mph, with Tory in the cab and Grant and Kari in the sedan, to see if the combination was....

Able to drive in a straight line.
Verdict - Confirmed

Notes - For the first test, Grant and Kari successfully pushed Tory backwards, but could not steer very well. They obtained a similar result in reverse, with the cab pushing the sedan.

Able to go around a 90-degree turn.
Verdict - Busted

Notes - Grant and Kari began by pushing Tory, but were unable to turn. When they introduced changes to replicate the movie scene more closely—wet pavement, bald rear tires on the cab—they obtained the same result. However, one last test with Tory pushing caused the cars to overshoot the turn and veer off in the opposite direction. Grant hypothesized that this result was due to the fact that the cab had rear-wheel drive, while the sedan had all-wheel drive; the cab's rear wheels slid out when it lost traction in the attempted turn.

Able to complete a 180-degree spin.
Verdict - Confirmed

Notes - After receiving some tips in defensive driving, Tory pushed Grant and Kari at 50mph toward a patch of wet pavement. When they turned their steering wheels in opposite directions, the cars went through a 180-degree spin, suffering some damage to their wheels and tires. Grant explained that the film maneuver was accomplished with extensive car modifications and a stunt driver.

=References=