Beck (29), better known as a duathlete, has competed successfully in international multisport events and has wide experience at the world championships.
Her best performance was fourth in Belgium at the under-23 event in 2004. Beck tried the long-distance powerman event for the first time in Weyer, Austria, in 2008 and won the international event.
This encouraged Beck to concentrate on the longer events. She was seventh in the powerman world championships in Zofingen, Switzerland, in 2008 in 7hr 40min.
The event consists of a 10km run, 150km cycle and 30km run.
Beck has built more distance work into her training under coach Tim Brazier and the Kepler Challenge will be less arduous for her.
Beck, who is contesting the Kepler Challenge for the first time, beat Crumpton when she finished eighth in this year's Hong Kong marathon. Crumpton was 14th.
Crumpton (41), who won last year's Kepler Challenge in 5hr 46min 2sec, has been handicapped this year by a serious foot injury. She will have surgery in Dunedin to fix the problem on Wednesday.
The Dunedin nurse has Haglund's deformity, a heel bone growth that has caused pain since she represented New Zealand in the marathon at the world track and field championships in Berlin two years ago.
Last year Crumpton led the women's race from the start and reached Luxmore Hut in a time only 40sec behind her own 1998 female record of 2hr 4min 18sec.
Vanessa Harverd, the 2009 winner and runner-up in 2010, and Sarah Coghlan (Queenstown), who was third in 2010, will challenge the Dunedin runners.
Defending men's champion Vajin Armstrong (Christchurch) will be challenged by Martin Lukes. who will be competing in the event for the 10th time.
Vajin won the Mototapu marathon and was a member of this year's New Zealand trail running team to the Commonwealth championships.
Lukes was second last year and will be keen to regain the title he won three times in a row from 2007 to 2009. He first contested the event in 1997 and finished runner-up in 1999, 2000, 2004 and 2006.
Tony Fattorini (New South Wales) is back for his fifth Kepler Challenge. He has been third three times.
Fernando Gonzalez (Spain) will be keen to add the Kepler Challenge to his list of conquests that include the Polar Circle Marathon (Greenland), Sahara Marathon and Himalayan 100 Mile Race.
Kepler Challenge
• The facts
Venue: Te Anau.
Distance: 60km.
First held: 1988.
• Records
Kepler Challenge: Men, Phil Costley, 4hr 37min 41sec (2005).
Women, Zelah Morrall, 5hr 23min 34sec (2003).
Luxmore Grunt: Men, Phil Costley, 1hr 52min 30sec (2008).
Women, Shireen Crumpton, 2hr 4min 18sec (1998).
