Nope, you can get springers as short as you want. It probably would take some machining of the headstock though to get almost any springer to fit. Here's a couple of old Triumphs with a fairly stock length springers on them.
My personal tastes though tun towards a non springer front end. Like this style:
If you'd like to look around and find all kinds of front ends and just different builds for old Triumph bobbers, check out the
Jockey Journal board. It's a great source if you're looking for ideas. Just about anything can be made to fit if you find a good machinist/builder.
edit: and after all that I finally went back and saw Pete's post about the long springer. Oh well/ You can either chop the frame just in back of the headstock and increase the rake, or have a new frame built.
