Originally Posted by Smallwheels

For somebody living in a city and riding on streets the small wheels are better. The faster acceleration makes riding fun. The wheels are stiffer and stronger than bigger wheels.

They do not roll over bumps as well as larger diameter wheels. That is why having a suspension helps keep the rider more comfortable. It is for this reason I bought a Dahon Smooth Hound. It has a front suspension. It smoothes out small and large bumps a little. It doesn't jar my wrists when it hits cracks or small holes. I put a Thudbuster seat post suspension on it and have a really comfortable bicycle.

Small wheels are not great for off road usage if having a smooth ride is one's concern. I had a recumbent with dual 20" wheels. When I rode it down a bumpy dirt road it was very uncomfortable because it didn't have a rear suspension. The design of the bicycle prevented me from being able to stand on the pedals to avoid the beating. With a rear suspension a 20" wheel on a recumbent wouldn't be a big deal.

Fatter lower pressure tires roll smoother than skinny tires. The problem with fat tires is their weight. With 20" tires the weight will be much less than 26" tires of the same width. They will still give the cushioning effect but will accelerate faster. This is probably only important with unsuspended bicycles. To me the benefit of having a suspension is to be able to have high pressure tires to roll faster and also have a more comfortable ride.

My Smooth Hound is for sale. (anybody interested?) I don't use it in the winter. Riding on snow is similar to riding off road. Bigger tires do better. I'll keep the big tire bicycle for now. If I move to a non-snowy area I'll switch back to a small wheel bicycle.