Ha! Nothing new under the Sun eh? Assuming that a Yamaha TMAX is a motorcycle and not an electric piano?
So I have a development to stop grinding the legs off.. Pop a bit of loose round bar in the tubular leg before welding it up and it will spin in the tube when the disc hits it and prevent further cutting. With luck it will shatter the disc and take an eye out..
A friendly policeman told me that one years ago for making grindproof window bars made of box section.