The aluminum skis used on the 1977 factory sleds were not the same as the ones used in 1978.
The 1977 skis were made from an already available extrusion. The tip was cut, then bent up, and the ski loop and the pieces cut to make the bend were welded back in.
The 78 ski is a tad taller of an extrusion, and a but thicker, giving it more support, and the ski-loop is bolted on vs welded in 1977.
Hopefully these photos will help clear up any confusion.
Thanks to Ken Simoneau for the photos!
These supports are supposed to be on 77 & 78 Skis. Painted black in 1978, in 1977, some of them got painted, some did not.
Note:The 1978 RXL ski had a steel support on either side of the spindle to re-enforce the aluminum where the bolt goes through. Our example for these pictures did not have that installed yet.
These supports were all painted black in 1978, in 1977, some of them got painted, some did not.
