CHEMISTRY INSIDE THE WHEEL: THE URETHANE MOLECULE [PART TWO]

CHEMISTRY INSIDE THE WHEEL: THE URETHANE MOLECULE [PART TWO]

The real artistry in making the ideal wheel comes in the choice of the A and B molecules. Long flexible molecules for B tend to give the urethane a low durometer - a wheel that is soft and grips the road. Choosing a rigid molecule for A tends to make the wheel stiffer. If you choose a B with lots of connection points, the result is a highly cross-linked elastic solid that is dense, strong, and very hard - a wheel with a high durometer will allow you to achieve higher speeds.

Chemistry Inside The Wheel Water Absorption Test

Arbor produces the Sucrose Initiative line of wheels. Ziegler explained that sucrose, common table sugar, acts like a B molecule with 8 places to form a urethane bond. This will make a wheel with many cross-links, which makes it firm. However, because of sucrose's flexibility, cross links in sucrose lend the wheel some flexibility. The multiple cross links increase the molecules strength, which makes a stronger wheel. This is why the Sucrose Initiative wheels leave fewer thane lines, extending the life of the wheel. Arbor created a fast wheel that grips the road with a long life span.

The urethane wheel has developed dramatically since the 70s and will continue to expand as the sport grows. Next time you ride, take a second to fully appreciate the chemistry that went into your favorite wheel.

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