Ok, now a rotary engine can't be beat as far as size & weight to HP & torque ratios, right?
And high RPMs are well loved by rotaries....

So, why aren't they used where size & weight (and high RPM) are most crucial, on motorcycles? Is there some 'fatal' flaw that would not allow them to work well in that kind of environement? Or is it just that no one wants to spend the billions of $$$ on R&D for a motorcycle application?

 

I think it was Suzuki that made one motorcycle and there have been some snowmobiles as well. Some remote control airplanes too. Do searches with "Wankel" as the keyword and you will find where they have been used of than Mazda.

 

Suzuki RE5
Norton

 

U can get a rotary for an RC car....cost ya about 400 bucks for the motor though....

 

Rotaries can't compete with high tuned piston engines. Motorcycle engine technology has always been years ahead of cars. Norton had some reliability issues and the power was just not there. Rotary's high reving is midrange to motorcycle engines which often exceeds 13,000 rpm.