Need fork post info

[Sgt. Howard]

Can somebody educate my ignorant self? I read banter about making fork posts fit a given frame with occasional mention of a 1" tube... here I am assumng the post itself, as the common OD I encounter is 1.5"... and I am noticeing the head tubes are 4.75" or larger. How many different sizes are there? And what options for connection are there if not threaded? The reason I am asking is this- I am conspireing with another lunatic... er... enthusiast... to ressurect the SAGER springer forks of yor, scaled to a 26" fat wheel and a bicycle frame. Also considering a minor re-design to allow either caliper or cantilever brakes (those that actually pivot from a boss on either leg of the fork, is that the correct term?) to be used o the design. Yes, I know- brakes on a true SAGER are a dangerouse proposition, that's why I'm doing the redesign.
the Old Sgt.

 

[loquin]

There's some info on this subject here. As I recall, cruisers and old mountain bikes are 1" diameter, and newer mountain bikes are 1-1/8" in diameter.

And, there are others...

Ref Sheldon Brown