“dandy chargers” (early nineteenth-century proto-bicycles propelled forward with the feet). Most of these caricatures seem to associate reckless biking with spoiled, foppish young men — interesting, then, that the last one shows an effeminate dandy getting smoked by what appears to be a naval officer:
"The Dandy Charger’s all the go,
Ten Knots an hour, Yeo, heave, ho
I scud along on this Machine,
While gaping crowds are laughing seen,
And every Dandy that I pass
I’ll leave sprawling on his A—!”
The first three caricatures are William Heath’s doing; not sure about the last one. Images courtesy of the British Museum’s online archive.