xr75 Ko Swing Arm

[Hardex]

Hi Guys. I need help on a XR75 Ko swing arm .I have been told the KO swing arm is different to other models.Can any one tell me exactly what the differences are ? Thanks.

[BETRIC]

KO/K1 swing arms have the pipe rolled and welded along it's length on the seam, later K3 arms are seamless like the K4, not sure about K2 XR75.   

[Hardex]

Thanks again betric.I have three swing arms and one has the welded seam and i didn't even notice that till now ,I must be going blind in my old age
Thanks.