Many years ago I decided to build a motorcycle style rocking horse for my grandson. Unfortunately it took much longer than I had anticipated to build it.
I had seen several different kinds online, many folks were selling plans or kits for ones they had designed. I wanted to style mine differently from all of them, and make it much bigger. Designing it from scratch was no small task. I made several mistakes along the way. Finding a safe way to attach the handlebar to the motorcycle, and then the motorcycle to the base was much more difficult than I had originally planned.
I also wanted to make it more functional than just a simple rocking horse. I wanted things like the saddlebags to be usable, the engine’s heads and crank case covers and other items to be removable using regular mechanics tools.
The biggest problem I had with the whole build was actually the very first part of the build. Or rather, what I made it out of. I wanted to use as much re-claimed material as possible. I had a ton of 1/2″ and 5/8″ pressed board in my scrap pile so that was my primary material for the chassis , wheels, and engine parts. Pressed board is just too porous, brittle and susceptible to tear out. I had to stop and re-design so much of this project because I used particle board A combination of hardboard and MDF would have been a much better choice the project would have gone much more smoothly and quickly.
Laminated front wheel, heads, chain and crank case covers 
I made a circle cutting jig for my band saw and to rough cut many of these parts. 
Then I made one for my router table to fine tune the parts and do the round-overs/cove cuts for each part. 
I seem to be missing the shots I took of chassis as I was laminating and shaping it. here it is with the hardwood tank, seat and forks attached. 
The rear and front fenders were also created with the circle jigs and laminating layers together.
I was actually stuck at this stage for way too long. I was too indecisive.