In the late 1970s my boys used to say dad can we build a bike? So off we would go to the local tip to find a frame and any good parts we could then bung the guy at tip some money and come home to start the build.
The Build would always have cowhorn handlebars (not bullhorn like the mtbs have but cruiser style. ).Nearly every build would require a different set of wheels due to the punishment they took as the boys use to build ramps out of scaffold planks and bricks to do jumps which kept getting higher.I built one bike which only lasted hours before my came in dragging the bike which the forks had snapped off.
There was not much health and safety for them at that time I must say I feel slightly guilty on that front as a dad I let them do some very dodgy things as they got bigger they used to ride my Yamaha DT 175 over some rough ground near us and they couldn't put their feet on the ground . one would sit in front of me and we would pull away slowly and I would slide off the back and then get back on after a few laps on his own.
It is so different now so many kids don't even get out the house.
I built a kart for my sons for this event and it won you will see what I mean about health and safety.
https://m.youtube.com/watch?v=AMmVTc14MjE