does anyone know how thick the bottom seatbelt mountings need to be? the ones on my locost are 3mm thick. i was thinking about doubling them up with a bit more 3mm. is this nesercery?

mine are only 3mm plate. as long as there's plenty of meat on teh triangle/web of steel and its fully welded i can't see it being a problem.

Ned.

Mine are 3mm triangles welded into the junction between chassis tubes, as the book. I kept the fixing hole reasonably close to the corner of the tube junction. Passed OK.