The activities of the mini-bike club included bike maintenance, trail riding, and group meetings for a total of about 6 hours per week. Members were rewarded with bike- riding time for appropriate behaviors such as regular school attendance and received predetermined penalties for deviant behavior. The 92 youths studied were all male except for 6 female probationers who took part in the recreation program. They were compared with respect to criminal offenses, status offenses, grade point averages in school, school absences, and score changes on the Index of Self-Esteem. The results revealed that the ecological group approach using behavioral methods appeared to offer the greatest potential for rehabilitating delinquents where many factors contribute to delinquency. Recreational activities were also more effective than probation alone, although they affected fewer of the outcome factors on which rehabilitation was measured. Results supported earlier findings that demonstrated contingent behavioral approaches to be more effective than noncontingent relationship approaches. Tables and 10 references