Spectacular Bid's attempt to win the Triple Crown ended ingloriously in the Belmont Park stretch today.

Coastal won the Belmont Stakes by 3 1/4 lengths because Bid did not display a semblance of the form that had earned 12 straight victories. The gray colt could not even hold second place from Golden Act, a decisive loser to Bid in the Kentucky Derby and Preakness.

Jockey Ron Franklin inevitably will be critized for his perfomance today, because riders always are blamed when a 1-to-5 shot is upset. But Spectacular Bid lost either because he was tired from the rigors of the Triple Crown campaign or because he could not handle the Belmont's demanding 1 1/2-mile distance.

"He choked - he couldn't get his breath at the quarter pole," Franklin claimed.

"I noticed it as we were coming into the stretch. He wasn't right. I had a lot of horse at the beginning, but when I asked him to respond, he didn't," the young jockey said in almost inaudible tones.

"I just pulled him wide and tried to finish the best we could."

The favorite ran into a fresh new challenger in Coastal, who had raced only three times this year and became a candidate for the Belmont just two weeks ago, when he won the Peter Pan Stakes by 13 lengths.

However, for the first mile of today's race, neither Coastal nor any other horse appeared likely to spoil Spectacular Bid's afternoon.

Trainer Bud Delp had revved up Spectacular Bid with a swift, short workout Friday, and Bid broke from the gate with much more alacrity than usual. "He was a bit rank before the race and also during the race," Franklin said.

Frankling rached the first turn in much better position than he had in the Derby or Preakness. He settled into second place, stalking the 80-to-1 frontrunner Gallant Best, and didn't lose much ground on the turn.

He also was safety in front of possible trouble from Angel Cordero Jr., the rider of General Assembly. Cordero and Franklin had fought this week and had been feuding since the Florida Derby.

Gallant Best covered the first half mile in a fairly quick 47 3/5, and Franklin might have chosen to keep stalking him and wait later to make his move.

But he already was pumping on his mount and pushed him to the lead after five-eights of a mile. After a mile, he had a comfortable three-length lead over General Assembly, and the crowd of 59,073 probably thought the outcome of the race was settled.

While Spectacular Bid was taking command, Coastal was going nowhere. He was on the rail in fourth place, where he had been for the whole race, but jockey Ruben Hernandez was asking him for a response and seemed to be getting none.

"At the five-eighths pole," Coastal's trainer David Whiteley conceded, "I thought we were dead."

Whiteley had decided with owner William Haggin Perry to pay the stiff supplementary fee to get Coastal into the Belmont, and he said, "At that point I wished we could get the $20,000 back."

But that was before Spectacular Bid started to negotiate the most demanding quarter mile in racing. There are many horses who can win at 1 1/4 miles but do not have the pedigree to handle 1 1/2. Spectacular Bid ran like one of them as he turned into the stretch.

Bid was tiring, and as Franklin whipped him left-handed he drifted off the rail, opening a gap Hernandez saw. Coastal had moved past the exhausted General Assembly, and now darted toward the rail to challenge the leader. Spectacular Bid offered no resistance.

The favorite was staggering through the last-quarter-mile in a pitiful 26 4/5 seconds as Coastal drew away with ease. Golden Act overhauled Bid by a neck to be second. Screen King was fourth, another 9 1/2 lengths behind.

Coastal paid $10.80, $4 and $2.10 Golden Act returned $5.40 and $2.10 and Spectacular Bid salvaged $2.10 to show for his backers.

Coastal covered the 1 1/2 miles in 2:29 3/5, a time Spectacular Bid could have beaten easily on his best days. But Bid had been racing and training hard for months, and he did not work as fast for the Belmont as he had for his previous races.

Delp said the colt was ready to run the best race of his life and threaten the track record if necessary, but those words suggested the colt's condition might be deteriorating.

That evidently was the case, and Coastal was the horse who was reaching his peak at the right time to take advantage of Spectacular Bid's temporaray decline. There probably will not be many other days when he is able to do it again. CAPTION: Picture 1, Ruben Hernandez guides Coastal Toward the wire to win the Belmont Stakes by 3 1/4 lengths. At left, Sandy Hawley rides Golden Act to the place, a neck in front of Spectacular Bid and Ronnie Franklin, right. AP; Picture 2, Coastal passes under the wire the winner of the Belmont Stakes. Golden Act, the No. 8 horse, and Spectacular Bid battle for second, a race won by Golden Act. UPI