Former All Black Carlos Spencer will be racing in the Whaka100 MTB Marathon presented by CamelBak on October 21st in the Whakarewarewa Forest, Rotorua.

The Rugby star has returned to New Zealand after living in South Africa and Japan in recent years. He is due to start a new job in December as assistant coach of the Hurricanes.

Although he has never been committed to mountain biking, he has committed to taking on the Whaka100.

'I raced in Cape Epic, but I didn't do the training that I needed. I was living in Japan at the time and only had four to five weeks to prepare for it.”

Spencer has only been on the Whakarewarewa mountain bike trails once, but looks forward to riding them again and having a bit of fun in the Whaka100. He is not setting goals or times, and will ride with his brother Fabian who raced in last years event.

'We just want to push each other along, and get a time we're both happy with. I've only been in the forest once and it was just a play around.”

His wife, Jo will be taking on the 50km. She has also only been in the forest once.

This years Whaka100 MTB Marathon presented by Camelbak is shaping up to be one of the best events in the 12 year history of one of NZ's toughest single day mountain bike events.

The 100km, 50km and 25km courses take in the world class mountain bike trails of Rotorua and the event runs from 20 - 21 October.

There has been a 21 percent growth this year, with a 7 percent increase in female riders. The increased growth of the event is not related to locals, but domestic entries with a large percentage travelling from the South Island and 96 percent of people traveling from outside of Rotorua.

Event director, Tim Farmer says the domestic growth is a great boost to the local economy.

'Many of the domestic riders spend time in Rotorua, familiarising themselves with the trails and enjoying the activities that Rotorua has to offer.”