Glass, Nails, Potholes... 'Flat-free' bike tires cannot pop

Glass is a non-factor. Ride over a nail even. The Acme tires cannot pop.

A new type of tire design, the Acme FlatFree Bicycle Wheels break the mold and use foam instead of air.

The result is a treaded rubber tire with foam inside made to mimic a tire inflated to 60 psi. The company uses Hutchison’s Serenity tube/tire combo as its base.

You may have seen these a couple years back when the “airless” tires grabbed buzz in the bike world and places like Popular Science magazine, where they won an award. But the product is just recently to market.

We got a pair to test and rode more than 100 miles on the foam.

The brand sells the wheels complete, ready to install on nearly any bike. They cost $299 for a set.

Right from the get-go we knew these wheels would add weight to our test bike. We weren’t prepared for how much: The front and rear wheels together weigh an astonishing 16 pounds.

The Acme FlatFrees are by no means performance tires. But they do accomplish what they set out to, which is never going flat. We rode through a pile of glass, over a metal shard on the road, and we bounced in and out of potholes to no ill effect.

“Invincible” is the best word to describe rolling through a city on these wheels. But another word to use would be “slow.”

On the road, spinning up to speed takes far more effort and time. It’s not just the weight, however, it’s more the physics of the foam reacting to the weight and forces of the bike and rider.

I figured the heavier wheelset would help me keep inertia up and require less work once I was moving. I was wrong.

Keeping my bike up to a moderate speed took more effort and energy than I’d ever experienced. Ironically, with all the extra required effort, it felt like I was riding with a flat tire already.

But to take a step back, these tires were not designed for riders like me. And if Acme can get more people riding who otherwise wouldn’t, I’m all for it.

Acme sells the setup in 26-inch and 700c size wheels. They come laced to singlespeed or gear-compatible hubs. Shimano coaster brake and high-end hub configurations are possible as well.

For anyone paralyzed by the thought of a flat tire, this wheelset is for you. They might work great for kid bikes, slow cruiser models, or for rental fleets. For most riders, however, I don’t forecast a rush toward foam anytime soon.

—T.C. Worley covers the bike industry for GearJunkie.