Two-time Olympic runner-up is a favorite to finally win title in London

Allyson Felix rented out a roller-skating rink for her 26th birthday and threw a bash with a 1970s theme.

She was a natural on skates, too, not even falling once.

On the track, she's even more graceful. Felix runs so effortlessly that her hair, done up in a ponytail, hardly even swings behind her.

She has long been the face of American track and yet her prime years are still ahead.

Felix the sprinter feels like she's running fast with the London Games approaching. But Felix the competitor worries she's running out of time to capture that elusive gold in the 200m.

So far, she has two Olympic silver medals in her signature event. A career without that title, well, just wouldn't be complete.

"I feel like if I walked away not winning it would feel like a failure," Felix said in an interview before the Olympic trials, where she earned a tip to London on Saturday night by winning the 200 with a personal-best time of 21.69 sec.

"Just because it's not my first Games, not my second, my third time. I've had eight years to think about being a silver medalist. This time I want to win."

Already so popular in the track world, Felix gained even more exposure over the last week - to a more mainstream audience, no less - when she and training partner Jeneba Tarmoh finished in a third-place tie in the 100m for the last Olympic spot in that event.

Being thrust into the spotlight hardly rattles Felix. When the cameras come on, she's well-spoken and very friendly - the ideal ambassador for a sport that's craving more attention.

Only, this time, she was silent. She hasn't been talking about the tiebreaker and how it will be decided simply because she wanted to put all her focus on making the team in the 200m.

That was priority No 1 simply because she wants to become No 1. Finishing runner-up in back-to-back Olympics does not sit well with her.

In 2004, she was the new kid and really wasn't expected to win, but gave Veronica Campbell-Brown a scare before the Jamaican broke away for the win.

Four years later, Felix was the favorite and was expected to take gold, only to watch Campbell-Brown capture another crown at her expense.

So heartbroken after the final in Beijing, Felix dissolved into tears.

Over her career, she's won high school, Diamond League, national and world championship titles in the 200. She has everything else, except the one crown she really covets.

Sure, she won Olympic gold as a member of the 1,600 relay in 2008 - a big deal, but just not quite the same.

Everything she does is set up with the 200 in mind. That's why she scrubbed her plans to run the 400 at trials, because it might make her more vulnerable in the 200. It did at worlds in South Korea last summer, when she tried to run the 200-400 double and finished with bronze (200) and silver (400).

So instead, she elected to run the 100 at the trials, because it would make her stronger for the 200.

Felix even trained a little different this offseason to prepare for London. She fine-tuned her technique, but also spent one day a week running around four miles on the road.

"It's nothing compared to the middle-distance runners. For me, it's like a marathon," Felix said.