Originally Posted by
theblackbullet
Fortunately I have this 1983 520 in my shed. I swapped most of the parts over. It'll help fill the gap while I'm searching for another early 80s tall mtb. I do plan on speaking with a framebuilder about repairing this one.
The 850 frame used a one-piece, bulge-formed head tube. The pseudo-lug shoreline on the head tube creates a stress riser that is prone to failure, although nearly 40 years service still isn't bad. Repair is likely possible, although the oversize top (1-1/8") and down (1-1/4") tubes may be difficult to find lugs to fit. Fillet-brazed head tube may be an option. Don't expect it to be cheap.
