CHANGLINGS

but so far I can see a dream based rider work

Chef Rider - a rookie chef who desires to fulfill his family's dream restaurant.

His motorcycle possesses a kitchen-like noodle cart.

What if KR Kabuto guest stars in that series? He'll be a support to the new rider.

Yeah, I was thinking of a delivery service Rider with his own growing restaurant, starting from the bottom and trying to become a master chef.

And then Kouta could be their delivery guy :lol.

How about riders based on superheroes?

but the helmets are masks. they mask their face from being seen by people.
that's the entire reason they are called "Kamen Riders"

I think the mask idea could work, by having the helmet as a blank slate with multiple masks to apply over the face.

By that logic super sentai is full of kamen riders as well. Masks all around.

edit: to clarify. Yes, the helmets in Kamen Rider function as masks. That's pretty irrelevant, though. When I say masks I mean, like, actual masks. I don't mean helmets when I talk about masks. Nobody does. Mentioning that masked riders wear helmet masks doesn't have any bearing on this idea.

That's the idea. Again, something kind of like with Ghost would be cool.

How about for the ninja rider theme, the kaijin will be based oni and they'll blend in the shadows - like with ToQger's shadow kaijin. Following Jackie Chan Adventures' oni masks concept, the oni will use masks to turn innocent victims into kaijin - as their slaves.

That's neat. Really, the only thing I can't think of is how the mask operates with the belt.

That'd be pretty interesting.