Fatboy, does the red swingarm have holes drilled in it underneath like the silver one?...it was explained to me by my welder that the holes are to let the gas out when they weld to get better penetration and strenght of the weld....they are more than likely recent copies (Novation?) as they didnt do that in the "olden" days
Once a tube is enclosed the heat from further welding increases the pressure inside the tube, that pressure wants to escape and will do so through the weakest point which is the weld pool.
That’s why we put holes in tubes but you only need to have one hole to fix this.
2 holes is for plating and anodizing so the solutions can get in and out as one hole would create a vacuum and stop the solutions running out freely.
Physics hasn’t changed over the decades, they still needed to do this in
Ye olden days but they may have been more discreet about it.
If you leave a tube open until all parts are welded to it then you can close it off and not worry to much about the hole but then sometimes pressure build up from heat treating can upset things.
A LOP arm from back in the day…
clever bugger arent I
Christ you can talk some shit
