I'd go with a beehive springer or similar. The Schwinn will not work right with that tank. Schwinn tanks work better because they taper down a lot near the head tube. The fork still hits but not nearly as early.
The best solution would be to send the rest of the bike to me and I'll send you a Schwinn to fit your springer. :lol:
If I recall correctly some old chopper motorcycles had chains that ran from the down tube to the fork. When you turned one of the chains would draw tight and prevent the fork from flopping all the way over.
Yeah, but if it hits earlier than a normal fork stop, that sort of thing can create unpleasant unintentional step-offs, :x :roll: if you know what I mean.