Cooper (20) was in control of the event a year ago before losing his chain on the downhill stretch from Signal Hill. He lost 23sec and went from leading to finishing third.
The Christchurch rider, who won gold at the Glasgow Commonwealth Games in the men's cross-country earlier in the year, is back for the third annual event.
Organisers expect about 200 riders to line up at the summit of Flagstaff Hill tomorrow morning, including 10 Australians, two Swiss and one French rider.
The five stages of the mostly downhill race will be held on Flagstaff Hill, Mt Cargill and Signal Hill.
Cooper, the 2012 world junior cross-country champion, races professionally for the Cannondale Factory team and goes into the race as the firm favourite.
Jamie Nicoll (36), who capitalised on Cooper's misfortune a year ago to win the race, is back to defend his title.
Nicoll, who spent months training in Dunedin a year ago, has recently returned from his first fulltime professional season competing in the enduro world series in Europe and America, and is primed for a shot at winning back-to-back titles.
Downhill specialist Sam Shaw (22), of Rotorua, will also press for a podium finish.
Shaw, a cross-country rider turned enduro specialist, came second in the inaugural Three Peaks race in 2012 and has speed to burn.
Rosara Joseph (Wellington) will be seeking a third straight title in the women's section, but will have her work cut out to hold off Meg Bichard.
Bichard (29), of Nelson, the top-ranked female enduro rider in the country, finished second behind Joseph last year but is coming off a successful international season, which included a few top-10 finishes in Europe and America.
Raewyn Morrison (25), who is also based out of Nelson, spent the New Zealand winter in Canada racing, and is a real chance for a top-three finish.
A year after winning the masters section and finishing third in the women's race, Dunedin's Anja McDonald is also one to watch. The first stage starts at 9.30am tomorrow.
-by Robert van Royen
