Straight cut gears are stronger, but noisier. Feeling was that the torque multiplied by the low gears could break things. The VP of engineering at Revcon was very well known in Formula 1 racing - wrote the book on aerodynamic down force. (The T22 he designed had enough down force that at 100 mph, it could have run around the track upside down) But anyway, racers can break anything, so I think that drove the thought process of the design.