Lots of kids are planning to enter the Bike Jamboree. There will be cross-country riding, an obstacle course, and even a contest for funniest bike. School bully Zack Jackson and his buddy Brett call the Hardys wimps. But is someone playing dirty to win the grand prizea twenty-speed mountain bike? Frank and Joe are determined to be good sports, but theres plenty of foul play. First Brett finds gum on his brake pad. Then somebody messes with Joes bike seat. Whos behind the nasty tricks? Frank and Joe gear up to find outbefore the big bike race ends in a big disaster!