In the early 1970s, skateboarding was all but dead. The first fad of the 1960s had faded, and the reason was hiding beneath the deck — in the wheels. Made of clay and steel, they gripped the road poorly, bounced on every crack and broke away into an uncontrollable slide. Salvation came not from the engineers of a big corporation, but from a young surfer who happened to spot a stack of rejected polyurethane roller-skate wheels at a factory — and realized he was holding the future in his hands.
This story is about how a single polymer pulled an entire sport back from oblivion. And about why polyurethane is still there wherever a material has to grip, roll and resist wear all at once.
- In the early 1970s, skateboarding declined because of hard clay and steel wheels that could not hold the road.
- Frank Nasworthy fitted a skateboard with rejected polyurethane roller-skate wheels — and the ride became smooth and grippy.
- In 1973, the first batch of Cadillac Wheels was released — and so began the second skateboarding boom.
- Polyurethane won thanks to three properties at once: grip, damping and wear resistance — and it still works on this principle today.
The hook: a stack of rejects nobody needed
In the summer of 1970, Frank Nasworthy visited the Creative Urethanes plastics plant in the town of Purcellville, Virginia. The business belonged to a friend's father and, among other things, was experimenting with polyurethane wheels for roller skates. A stack of rejected wheels was lying around at the plant — and the boys were allowed to take them.
At home they fitted these urethane wheels onto a skateboard. The effect was instant: instead of a harsh rattle and slide — a smooth ride and grippy traction on the asphalt. In 1971, Nasworthy moved to Southern California — for the surfing — and noticed that local kids were trying to skate when there were no waves. He asked his father to send ten sets of those same wheels. Investing 500 dollars earned at a restaurant, he founded the company Cadillac Wheels — the name was chosen for its association with the smooth ride of a luxury car. The first batch of wheels stamped with the "Cadillac Wheels" logo came out in April 1973. So began the second skateboarding boom — and the modern skateboard, in essence, still rests on that discovery.
Why polyurethane in particular
To grasp the scale of the leap, you have to look at what came before. Clay wheels (actually a composite of ground material with a binder) were cheap, but hard and brittle: they had almost no grip, chipped against curbs and turned every bump into a jolt. The even earlier steel ones rolled fine across a smooth shop floor, but on the street they held the road not at all and transmitted every vibration straight into the foot.
Polyurethane solved all three problems at once — because it is an elastomer with a rare combination of properties.
- Grip. The soft, resilient surface deforms over the micro-irregularities of the asphalt and "hugs" them, delivering a real coefficient of friction where a hard wheel simply slid.
- Damping. The viscoelastic nature of polyurethane absorbs small impacts and vibration, so the road stops "hammering" at your legs.
- Wear resistance and elastic recovery. Polyurethane handles abrasion excellently and returns most of the deformation energy, so the wheel both rolls a long way and lasts a long time.
Hard materials give you one thing; polyurethane gave everything at once.
Technical note: the same chemistry as in today's components
Historically, Nasworthy's wheels were cast from cast (thermoset) polyurethane — liquid components were mixed and poured into a mold, where they cross-linked. Today, alongside it there is a thermoplastic relative — TPU (thermoplastic polyurethane), which does not cross-link permanently but melts and can be reprocessed by molding or extrusion. Chemically they are close: both are built from alternating hard and soft segments, and it is the ratio of these segments that sets the hardness — from soft wheels to hard rollers on the Shore D scale.
The key property Nasworthy discovered has not gone anywhere: modern industrial wheels, conveyor rollers, forklift casters and countless wear-resistant components are made precisely from polyurethane — for that same balance of grip, damping and abrasion resistance. The technology has changed (thermoplastic instead of casting alone), but the physics has stayed the same as on that rejected wheel from the Virginia plant.
How this relates to our industry
The Cadillac Wheels story is a fine reminder that a material's properties decide the fate of an entire product. Back then, polyurethane beat clay not with advertising, but with physics: grip, resilience, wear resistance. Today, that same class of materials — thermoplastic polyurethanes — remains a working tool for the engineer wherever a part has to flex, cushion and resist wear for a long time.
In the Exaflex® line we supply TPU across a wide range of hardness — from soft grades for flexible parts to hard ones, closer in character to those same wear-resistant wheels. Selecting the hardness and type of polyurethane for a specific application — from seals to rollers — is something we support technically.
Exaflex® TPU — polyurethane lineFrom soft 80A to hard grades on the D scale · grip · damping · wear resistanceChoose a grade with a specialist → Exaflex® TPU 95AHard TPU for loaded wear-resistant parts · high hardness · abrasion resistance · elastic recoveryClarify supply terms →If you are curious about how the hardness of polyurethane relates to its structure, read more in the article what is TPU.
A few technical questions in closing
Why did clay wheels lose out to polyurethane ones?
Clay (composite) wheels were hard and brittle: with almost no grip, they slid, chipped against curbs and transmitted every vibration into the foot. Polyurethane is an elastomer: it deforms over micro-irregularities and delivers real friction, absorbs impacts and is wear-resistant at the same time. Hard materials could not deliver this combination.
Are cast polyurethane and TPU the same thing?
They are close relatives. Historical skate wheels were cast from thermoset polyurethane, which cross-links in the mold. TPU is thermoplastic polyurethane: it does not cross-link permanently but melts and can be reprocessed by molding or extrusion. The segment chemistry is similar, so the properties are shared, while the processing technology differs.
What gives polyurethane grip where a hard wheel slides?
The soft, resilient surface deforms under load and follows the micro-relief of the road, increasing the area of real contact and the coefficient of friction. A hard wheel touches only the peaks of the irregularities — hence the sliding.
Why do polyurethane wheels last a long time?
Polyurethane has high wear resistance and elastically returns most of the deformation energy instead of dissipating it as heat and damage. That is why the wheel both rolls easily and wears down slowly.
Where is that same property used today?
Industrial wheels and rollers, forklift casters, conveyor rollers, wear-resistant bushings, seals and cushioning elements — all of these are made en masse from polyurethane for that same balance of grip, damping and abrasion resistance.