1) Specialized Carve 29 HT.
2) Not having ridden the Specialized Carve 29 HT prior to purchase.
3) My failed attempt to break the land speed record on a Raleigh Chopper in 1975, which resulted in a violent speed wobble that spat me off at 312 MPH (it seemed) and broke my leg. Next time I try I'll do it without a pillion. So, technically the regret is my Dad buying me a Chopper and not a ten speed racer, on which I'd have doubtless smashed the record.