Cyclists from around the world are riding out of Black Diamond this afternoon in the fourth phase of the Tour of Alberta.

The five-stage tour started Tuesday in Edmonton and wraps up Sunday in Calgary. The 900-kilometre race is the first of its kind in Canada and, so far, organizers say it has been a huge success.

"We're going day-by-day and we wanted to have a big day in Edmonton then next day, got a little bigger," said executive director Duane Vienneau. "It is building. We're hoping by the time we get to Calgary on Sunday, we have a massive crowd and cheer these guys on for the overall finish."

More than 115 of the world's top cyclists have worked their way south from Edmonton, through places like Camrose, Red Deer and Strathmore.

For many, the race is an opportunity to change cycling culture in Alberta.

Crowds of supporters have been larger than anticipated and for the riders, that's a welcome surprise.

"The cyclists are shocked," said Vienneau. "Maybe not shocked but pleasantly surprised by the crowd turnout. Spectators have been great everywhere we've went."

The final stage of the race starts in Okotoks on Sunday and ends in southwest Calgary.