Thump, thump, thump, thump.
Big, single-cylinder engines have always been a bit of a rarity on the market. While the single-pot layout was a rather popular one for sub-400cc bikes throughout the years, you would rarely see the cylinder reach a displacement of more than 500cc—with a few exceptions of course.
Nowadays, most manufacturers tend to opt for more efficient two or four-cylinder units, leaving mainly dirt bikes to hold the “mono” fort.
There is, however, a handful of 500cc-plus modern and road-legal models that defy the odds and continue to rock a single thumper. If you like the... unparalleled feel and character of a mono-cylinder, you might want to check these models out.