It sounds like it belongs in the ACT Brumbies' playbook. Instead it's the moment their carefully planned ride to Mt Kosciuszko came unstuck.

Just out of Tharwa and on the first real descent of their three-day ride yesterday morning, Mafi found himself on the ground and bleeding, the first and hopefully last casualty of the charity fundraising expedition.

The Brumbies have left little to chance in preparing for the ride, which has raised money for OzHarvest Canberra and Outward Bound community projects.

The selected route purposely avoids major roads, the players were given riding training from top mountain bikers and they are wearing flouro vests to make them stand out on the dusty roads.

Coach Andy Friend put Mafi's accident down to the group he was with riding alongside each other and not in single file, as instructed. While he admitted to anxiety seeing his players making steep descents, the rewards of the team-bonding exercise would outweigh the risks.

''We've reiterated it's not a race, it's a journey and it's about getting through it. The downhill stuff is the scary stuff. We need to be careful, which we are, and we'll keep our fingers crossed we'll have no more accidents,'' Friend said. ''Aside from Alfi's fall, it's been tremendous today and the guys are in good spirits.''

Having ''taken off some bark'', Mafi will now be forced to join injured players such as skipper Stephen Hoiles travelling by team car ahead of the riders. That group has been doing gym sessions in the towns along the way and has the job of setting up camp ahead of the riding group.

While disappointed to be forced out of the ride, Mafi was relieved his injuries were only superficial.

''It was going well, everything was going to plan until I fell,'' Mafi said.

''Christian cut in front of me, I had to go around and I fell. I wanted to go on this ride and to get injured on the first stage is very disappointing.''