fork tubes

[schachterle]

What year fork tubes are interchangeable with what year triple trees?

 

[Classic]

This should be everything you need to know.

Mid-'77 the front forks had a major redesign, fork tube diameter increased from 34 to 35 mm and internals were changed (although this also holds true for various years of the same tube size). The entire fork assembly (with triple tree) will swap either way but fork parts are not equivalent. Also the brake caliper changed from a 48 mm dual piston cast iron design for the 34 mm fork to a 40 mm aluminum single piston floating caliper for the 35 mm forks. The brake caliper mounting lugs on the fork sliders are of different spacing for the 34 mm and 35 mm forks so the calipers can't be swapped.