By Keith Coffman

DENVER (Reuters) - There is no shortage of horse racing fans who believe Big Brown will win the Triple Crown, but Penny Chenery's opinion carries more weight than most.

The 86-year-old Chenery's colt Secretariat claimed the coveted honor in stunning fashion 35 years ago, scorching around the 1 mile Belmont Park track in 2:24, a world record that stands to this day.

She believes Big Brown has all the elements to claim the Triple Crown, but chuckles when asked about the possibility of setting a new world record time.

"To win the Triple Crown a horse has to have speed, stamina, soundness and a lot of poise," Chenery told Reuters in a telephone interview on Thursday.

"Big Brown seems to have plenty of all that," she said, adding however: "I think that record will stand for a while."

Chenery will attend the Belmont Stakes on Saturday in New York and is rooting for Big Brown to become the first horse since Affirmed 30 years ago to bag the elusive Triple Crown.

The one-time owner of Meadow Farm, a Virginia ranch that also produced 1972 Derby and Belmont winner Riva Ridge, she now lives in retirement in Colorado.

Chenery says she keeps an eye on the horse racing world and was impressed by the burst of speed Big Brown displayed pulling away from the field at the Preakness three weeks ago.

However, it will be a challenge to match Secretariat's 31-length victory at the 1973 Belmont that raised the bar for all thoroughbreds.

The triumph also secured the first Triple Crown since Citation in 1948, and ushered in a decade that produced two more winners, Seattle Slew in 1977 and Affirmed the following year.

'SHEER JOY'

The owners of Seattle Slew and Affirmed, Sally Hill and Patrice Wolfson, will join Chenery at the Belmont and will jointly present the Triple Crown trophy to Big Brown's connections should the Kentucky-bred colt, a 2-5 favorite, pull off the victory.

"We've been going to the Belmont for years and we always sit together," Chenery said. "Hopefully this year we can present this really elegant, triangular trophy."

Chenery said the sport's breeding techniques that focus on early speed rather than durability has made it difficult for a horse to win the Kentucky Derby, Preakness and Belmont Stakes.

The bloodline that dominates the industry has hoof-weakness traits that have resulted in breakdowns, most recently by the filly Eight Belles, after she finished second in the Derby.

"They are bred to sell, not to race," she said.

Casino Drive, the 7-2 second choice in the Belmont that some feel poses the biggest challenge to Big Brown, is not of that bloodline, she noted.

Nor was Secretariat, who was in a class of his own at the Belmont in 1973.

"He was so far ahead that he couldn't hear the other horses, and so he was running for the sheer joy of it," she said of her chestnut stallion, nicknamed Big Red, who died in 1989.

"I think he could have gone around the track again."

(Editing by Peter Rutherford)