Primo Comets are bicycle tires. They should work equally well on a 'bent or an upright bike. I suspect they are on a lot of 'bents because of Primo's connection to BMX bikes. Most BMX bikes use 20"/406 tires, as do lots of 'bents.
I'm considering putting them on our upright 26" wheeled tandem when the current tires wear out.
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Bacchetta Giro A20, RANS V-Rex, RANS Screamer