I think the 4 stud came in 1948. Though some say that some 5 studs was made in -49. My first speedway bike was a 5 stud JAP back in 1969. Not bad from tapes up to first corner, then the JAWAs with better handling frames took over. The 5 stud had an aluminium conrod which over time got longer. If not replaced in time the engine exploded. 4 studs has steel conrod. You had to have blacksmiths hands when changing from warm up spark plug to race plug.
It has been done, I have seen at least 2 examples here on RU-vid. Obviously the mods would depend on local regulations and laws, and it might not be able to happen everywhere.
@@TombstoneHeart I guess so. The vids I watched didn’t go into specific detail but they had rudimentary brake system with associated brake lights. And also the right side foot peg was removed or repositioned to another spot. I am not even sure what fuel they ran on either, I would guess regular petrol and not methanol. They had license plates attached too so one must assume they were somewhat road legal. I imagine some countries aren’t too fussed on maintaining some standards.
