tatfriend, so because motor vehicles use technology first developed for bicycles, cars are hybrid bikes, too? Haha, just kidding.

The addition of chain drive allowed the use of a smaller front wheel, the low safety was a big change from the Penny-farthing with it's huge front wheel. Definitely a hybrid of the existing bicycle and something.

I don't know much about history, but my limited research seems to indicate trikes featured chain drive in the 1860s, while safety bikes came out in the 1870s. Bicycles already had wheels, cranks, frame, fork, headset, handlebar, saddle. The only thing added was a chain, but it resulted in a machine that was different enough to be a new variety of human powered transport, in my opinion.

So, I think of it as a hybrid. Penny-farthing riders held a similar opinion of safetys that roadies have of hybrids today. Good for those with physical limitations that would prevent them from riding an ordinary bike.