Gee Atherton, 23, and his sister Rachel, 20, are two of the world's leading mountain bike riders.

And the English siblings have targeted Canberra as their next destination to conquer on their way to what they hope will be World Cup glory.

The Atherton's will be among the 200 riders competing in the Mountain Bike World Cup at Stromlo Forest Park this weekend.

The Canberra leg brings an end to a six-week tour for the pair, which also included a month in Canada.

And while their on-track success has been first-class, their off-track antics have been a bit more hit and miss.

''We've had some great rows, some quality arguments,'' Gee said yesterday after he and his sister had walked and rode the Stromlo course in preparation for Sunday's downhill event.

''We're at the end of a six-week world tour together. We're pretty tired and stressed there's been some good arguments, trust me.

''That said, we actually do get on pretty well together and are good mates, but obviously we both have our moments.''

Rachel agreed with her older sibling.

''We spend a fair bit of time together obviously and it's not too bad most of the time but we have some good fights,'' she laughed. ''We've had a couple since we got to Australia a week ago but we generally sort ourselves out quick enough.''

The Athertons aren't here for a holiday or to simply make up the numbers. Both are the reigning world champions in the downhill discipline for their respective genders.

Rachel is also points-leader in the race for World Cup glory with two races to go, while Gee is in third place.

Victory in Canberra this weekend would have them in pole position for overall honours with one race remaining, in Austria in two week's time.

They had their first look at the Stromlo course yesterday and were impressed with what they saw.