This challenge will be really funny! I was looking for some kind of diferent vehicles on web, and I found this:

https://img47.imageshack.us/img47/955...adster26gg.jpg

https://img52.imageshack.us/img52/408...adster37vj.jpg

https://img52.imageshack.us/img52/761...trane104kd.jpg

This dude has made a very interesting kind of monocycle. More about it:
https://www.torpedo-emscher.de/wr/uni...etroadster.htm

And I guess I'm going to base my tranformer on this monocycle. Of course, I will have to make some improvements, like add guns and more volume to the monocycle. But it looks real great for this purpose!
Next step is work on concepts. So, let's go!