Power Rider was rumored to be a Kamen Rider Adaptation of Kamen Rider Fourze. It's title is a name mashup between Power Rangers and Kamen Rider. It's unknown if it would've followed Fourze in some fashion. So, this seems like a popular show, what happened? Well, Haim Saban lost interest in it and decided to abandon the idea. Meaning that they decided that Power Rangers is the only thing they can do by now. But, a Kamen Rider adaptation isn't completely gone, people are coming up with the idea to adapt Gaim, the most popular KR series. So, you'll never know what would come next for American Kamen Rider.
This is the only photo to prove the existence of Power Rider. A lunchables box with Fourze on it.