I'm thinking an XV could convert fairly simply. A pair of curved tubes of appropriate metal and section from the rear spindle up to the top shock mount, amputate the monoshock metal on the swing arm. Change to skinnier rims, front and back? Forks and brakes, for a road bike, leave them standard and in good order. The XV may well be "slow and outdated" in journalist terms, in the real worl, it will still hurl you forwards at a fair old rate.