390 AMX test from '77

[PEZBerq]

My 78 390 AMX is very original and has the top swing arm in Marks photo. The poor old autos certainly got the hand me downs . Doe this make my 78 auto eligible for pre if I restrict the suspension gravel to 9 inches?

[PEZBerq]

Studying the photos in the October 77 Dirt Bike test of the 390 auto posted above I am pretty sure it also runs the same swing arm as the 76 CR shown in the photos above.

[Husky500evo]

I took some measurements, because the swingarm in the 390 Auto test looks longer than a '76 CR360 arm. The  '76 CR360 and '77 CR390 swingarms are both made out of  32mm O.D tube, but the '77 swingarm is 30mm longer at 555mm overall (compared to 525mm for the '76). The '78 CR 250/390 swingarms are made out of 40mm O.D tube.

[PEZBerq]

Confirmation the 78 390 AMX uses same swing arm as 76 CR model....hand me down on the auto is even more serious than I suspected . Only one cross brace used.