Flat tire on your car? Just mount up a spare bicycle wheel

Car on bicycle wheel
Bill Mould is a custom wheel builder who recently partnered with a high school senior to build a wheel that could support the weight of a small car. For the experiment, which he worked on with Bryan Higgins, they used a 36 H Velocity Hub, Cliff Hanger Rim, Sapim Spokes, and a Maxxis Hookworm tire.

Head past the break for the full video.


A corolla weighs roughly 2700 lbs, and has a ~60/40 weight distribution, which means this wheel is seeing aprx 540 pounds of static force – which is less than the dynamic force a BMX wheel experiences when slammed into the ground by a 200 lb rider.

The moral of the story? Bicycle wheels are pretty tough, although we’ll be sticking with our spray painted steelies!

Comments

22 thoughts on “Flat tire on your car? Just mount up a spare bicycle wheel

  1. I hope Velocity is willing to throw a few hubs and rims his direction. They got some good publicity out of this.

  2. Neat, but wire wheels for cars are not a new thing, they just don’t work as well for the application as cast/forged wheels.

  3. I took his wheelbuilding class. He showed me what he was doing with that wheel, and said Velocity had given him the rims/hubs.
    He makes nice strong wheels, I strongly recommend taking the class vs. having him just build the wheels, if you want handbuilt wheels.

  4. Bill is a cool cat! I had the fortune to take bike maintenance and wheel building classes that he instructed. He’s an interesting guy.

  5. Interesting that he wanted to let some air out of the wheel to “keep the tire pressure from going too high”. A small misunderstanding of how tire pressure and the tire’s contact patch interact.

  6. A fun project. But a properly wheel should not ping! If the spokes are wound up after building, you’ll get pinging as the spokes unwind and screw themselvs out of the nipple a little bit. Then the wheel needs retruing.

    How about using a 24″ wheel instead, to better clear the wheel arch?

  7. I have a few questions (realizing that this is an experiment and probably not something he is out driving around on today):
    Does the bike hub have bearings that turn? So, no brake on that wheel?
    What is the dynamic force of a 2700lb Corolla with at least one adult inside while driving?

  8. Toms comment above is spot on. A bicycle wheel will not tolerate anything near the lateral force that a cornering (even at VERY low speed) will exert. Tire roll off and/or wheel collapse imminent! Interesting party trick though…

    JasonK, the tire pressure misunderstanding is this: There is a direct relationship between tire pressure and contact patch. No amount of weight will ‘increase’ the tire pressure, it will only vary the contact patch. At 30psi, a 540 pound load will have a contact patch (flat spot on the tire) of (540/30) or 18 square inches. In a 3″ wide tire that’s roughly a 6″ long flat spot. In a 1.5″ tire that’s a scary 12″ long flat spot. That’s the real concern. the sidewall is almost compressed to zero.

  9. A dually version of this would actually work incredibly well, even in the real world. A hub with 4 (or just 3) spoke flanges wouldn’t be that hard to create for this.

  10. Interesting project, cool to see that the wheel can support the weight. I’m curious how it would handle lateral forces and braking forces though, I have a feeling the spokes on true car wheels are much thicker for a reason.

  11. im not the same greg, but:
    as a tire is compressed, the internal air pressure rises only negligibly. more tire surface is in direct contact with the ground, pressure per square inch, you get the idea.
    even that model doesnt hold perfectly true for car tires or others with stiff casings, radials, etc., but should be pretty accurate for bikes n their nice, supple casings.

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