Don't let the term "mini" fool you into thinking they are for kids; an "upright" mini sprint (also known as a lightning sprint) is the exact same physical size as a full USAC/POWRi Midget, the major differences being a mini sprint uses a motorcycle powerplant and chain drive, and doesn't have power steering. I'm 62 and started running one in the Montpelier Midget Series last year and I'm having an absolute blast.