A Wellington motorcyclist who hit and decapitated a sheep at about 100kmh believes he could have been for the chop as well if he had not been wearing good safety gear.

James Hailstone's powerful motorcycle was wrecked as he hurtled 100 metres down the road after the collision, before crashing through a roadside fence near Masterton on Saturday.

Mr Hailstone, a 32-year-old software tester, came out of Masterton Hospital yesterday, saying: "I'm happy to be walking and talking."

He was "still hurting and a bit sore", but said he came off lightly, with a dislocated thumb, a chipped ankle bone and bruised intestines.

His leathers were torn, his new $1000 helmet was wrecked and his chest protector was ground down as he skidded face down along the road.

He was convinced his safety gear saved him, although he could not remember what actually happened between the time he turned on to the road and when he later woke up in hospital.

At the time he was riding in convoy with a small group of other Wellington motorcyclists, one of whom was a trauma nurse.

The accident happened in Stronvar Rd, a stretch east of Masterton dubbed locally as "The Mad Mile".

The section of road features a long clear straight and has a history of being used by racers.

Mr Hailstone said his 1000cc Yamaha was a writeoff and he had no intention of getting another bike immediately. "I'll take a few months off, as I want to get right first. Motorcycling is a passion but I'll put it off till later this year."

Farmer Guy Williams said the crash left a grisly sight on the road. "From what I've been told the [ram's] head's been taken clear off, along with a shoulder."

The motorcycle carried on for more than 100m before going through his fence.

"He must have been going at a helluva speed to take its head off - he's lucky to be alive."

Sergeant Rick Joblin, of Wairarapa, said police could not confirm Mr Hailstone's speed as "the sheep can't tell us and the rider has concussion". The identity of the farm could also not be determined as the ram's head - including any ear tags - had not been found.

"Poor sheep, but poor motorbiker by the sounds of things as well," Mr Joblin said.

Mr Williams said he had yet to determine whether the sheep came from his farm.

- © Fairfax NZ News