I went to a Harley Riders Club rally with my mate this weekend (I have a Yamaha cruiser as well as my Suzuki GN400) and saw a very rare thumper. It was a single cylinder Buell which my son-in-law who is a previous Buell owner informs me is called a Buell Blast.
Basically it is a Harley Sportster motor with the back cylinder chopped off. Given that Sportsters don't produce massive power to begin with I presume it is a nice old plodder.
Great rally, good weather and a thumper, what a weekend!