I used to rent a movie when I was little about a group of friends(guys). I'm pretty sure they were teenagers. It starts with one of the guys at the top of a tree while his friends sawed it down(I guess they dared him). They built this fort thing. I guess the fort was their hangout. They were training for this race. It was like an obstacle course. They were rivals with another team. They needed a girl on their team so they asked this tomboy to join. She always wore braids in her hair. There was a part where the girl was practicing by herself and she passed out. One of the boys saw her and helped her... turns out she had diabetes. They went to her house to watch a movie one night, her hair was down and they were shocked that she looked like a girl. The main boy had a crush on her. On the day of the race, the main boy didn't show up for some reason. His part was to do the bike race part of the course. I guess he changed his mind or something and jumped on his bike to get to the race in time. On the way the chain to his bike fell off. He eventually made it.That's all I can remember. I assume they won in the end. It was the second part of another movie. I can't remember that one either. It probably came out in the late 80s/early 90s. This has been driving me crazy for over a year. Id appreciate it if anyone can help with the title or remember more about this movie.

I think I found it! It might be Little Marines 2. Ill have to buy it to find out.