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Comment by anonymousiam | Hacker News Reader

These small bicycles have one major disadvantage: The wheels are too small to provide much of a gyroscopic effect while riding, so they are far less stable than a traditional bicycle. https://www.exploratorium.edu/snacks/bicycle-wheel-gyro

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This is largely a myth. A rotating bicycle wheel does generate a small amount of gyroscopic effect, but it is too small in comparison to the weight of bike & rider to make much difference. People have built bicycles with counter-rotating front wheels[1] to prove it.

Smaller bikes may feel less stable, however I suspect this is simply because smaller wheels will be affected by smaller road imperfections that a larger wheel would simply roll over.

[1] https://theconversation.com/how-does-a-bike-stay-upright-sur...

I wonder why there are so many conflicting opinions on this.

It may be that those trying to discredit the benefit of gyroscopic stability are looking at the first order effect of the gyro/wheels on keeping the bike upright, when in fact it is the force from the front wheel on the handlebars/steering, and the man-in-the-loop.

https://ezramagazine.cornell.edu/summer11/researchspotlight....

Own and ride a Brompton, which has 16" wheels. It's perhaps marginally less stable than a full-size bike, but I'm willing to believe that it's mostly down to steering geometry (smaller wheels limit how far behind the intersection of the steering axis and the ground you can put the contact patch) not gyroscopic effects.

For a proper judgment of the riding characteristics a look at the practical use when riding downhill could be helpful:

https://www.kwigglebike.com/en_US/faltrad-vs-rennrad-am-berg

This ride felt absolutey safe.

The large advantage is that the wheels are very light, and spin up with little inertia. On my Brompton, I break away from red lights instantly, faster than road bikes.

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