"Leaky", or "being leaky"; a "leak" - A derogatory term used in motorcycle flat-track racing, usually in professional racing, to describe a rider with illogical, unpredictable or unorthodox racing tactics.
A rider who often strays from the normal racing lines into and out of corners, for no apparent reason. An untalented and often dangerous rider.
"Be careful riding near #45. He's leaky; you never know where he's going next."