The following race classes are actively supported by the CMPRA:

Club 20 - Hand launched .20 cu in powered models. Suitable for beginners.
Electric - Hand launched. Brushless motors. Intermediate class.
FAI F3D - International racing class using .40 cu in motors. Hard work.
FAI F5D - International racing class using brushless electric motors. Also hard work.
Q40 - .40 cu in motors. Not quite as fast as F3D but a lot easier to compete in.
Q500 - .40 cu in motors. Simple airframes. Another good beginners class.
Speed 400 - Speed 400 electric power. Slowest of the classes. Ideal for beginners.