A week ago Vincentia High School student Sami Cavill, 13, thought she would spend her school week copying notes and reading books in her south coast classroom.

Instead she was preparing yesterday for a breathtaking race against 530 students in the ACT school Mountain Bike championship at Stromlo Park today.

Before her friends asked her to join them in the team event, Cavill never thought about mountain bike racing. Luckily her father had a bike suited to the harsh terrain of the Canberra course.

''Dad doesn't really use his bike much any more,'' Cavill said as she prepared for her first ride yesterday.

''I haven't done any riding before but dad's bike was there and my friends needed one more person to make the team. So I said I would join. Now I'm just worried that I'll go slow and let them down.''

Along with 230 first-time and beginner riders, Cavill went on a tour of the course yesterday.

Race course instructor Shane Paton took groups of riders around the course to point out the difficult sections.

Paton said a first-time rider could work their way through the field and finish in a high position.

''The whole point of something like this is to get the guys out there so they know what they are up against come race time,'' Mr Paton said.

''But once they get out and see they get a bit more confidence and it's great for the experienced and beginner riders.

''The last thing we want is anyone to put themselves in danger or have an accident.''

Although Cavill and her team were unable to win the School championship, because they are from NSW, they were still eligible to win medals.

But Cavill said she was happy to help her team finish the race, even if that meant finishing last.

''It really does look like fun,'' she said.

Fellow Vincentia student Aidan Cameron, 12 couldn't wait to get on the bus and come to Canberra.

He doesn't care about winning and he doesn't care about crashing.

''It's great when you get a chance to stack your bike,'' Cameron said. ''It's just fun and gives you a chance to exercise.''

2008 UCI MOUNTAIN

BIKE WORLD CUP

Saturday and Sunday at Stromlo Forest Park, including Cross Country Round 8, 4X Round 6 and Downhill Round 6. Entry is free. For more details visit www.mtbworlds.com.au