Hello Marair23, I did a couple of "stretched" bikes a few years ago. But, some things can get kind of goofy when working with bicycle frames and at the point I had done this one in a traditional "chopper" style 6" out and 5" up I was seeing that. This bike is very long, the forks are 43".
The red bike with the Chinese 2-stroke was the last of that sort I did. This pic was resized in November of 2004, Chinese under frame tank, ladies cruiser I made the sprocket from a bicycle sprocket (much more "round", I have a few of those left 44 teeth, tho they are not drilled with the large lightning holes.) This bike is stock Cruiser wheelbase. I am currently looking to do another bike, and may re-cut this one to be a different animal.
It was now becoming clear to me that I needed to build a frame that had all the details I needed. Wide drop-outs for sheave (or sprocket), man-sized between the saddle and bars, and traditional in it's design. More than enough room in the "engine compartment" was also in order.
In the process, I had some problems with rake, and other details. AFTER I had designed, and done two "do overs" and was riding the first Prototype bike, I got a chance to do what I needed to do first which was to measure an original bike.
The wheelbase (axle to axle) on this blue Original 1910 Excelsior measured about 53". Having the information I now have, I will use as many original dimensions that I can.
This Red Racer is a little short on rake, and might be an inch taller than it could be, however it is close.
I hope some of this helps you,
Mike