I've been on rigid long bikes since the 1970s so I'd do something with the Softie and leave the Sportster as is for a number of reasons.

There's a gazillion aftermarket rigid frames available for the Softie in the $700 price range plus the entire aftermarket is based on the big twin Evo Softail so all the other parts you'll need are plentiful and cheap. Also, a stock Sportster (for those of us who aren't snobs) is an almost perfect machine that's a blast to run around on bone stock.

As for rigid vs. sprung frames it's all in the ergonomics. The bike must fit you like a glove or you'll be miserable. What I mean is the handlebars, seat, and foot controls must all work together so you're as comfortable as possible. Often you'll have to compromise between looks and functionality. For instance rigid bikes generally always look better with a slammed seat but solo seats with springs under them is really the only way to go.

Nowadays rigids are considered by most to be bar hoppers but you can go as far as you want as fast as want just knowing you'll need to stop and take breather more often than other folks. And so what? What's the big hurry? I'm almost 60 years old now and yes, I'll admit from time to time I hear those big comfy baggers calling my name but I'm going to stick with going my own way for as long as I can.

I don't want to end this without saying a word about the bike building process itself. Doing a frame-up build is a very rewarding process with many benefits down the line. You built it, so you'll know everything about it. This makes maintaining it much easier. You'll already know where any weak spots might be (where you fudged things a bit) so you'll know to keep an eye on them. And when anything does break you can fix it. Rigids, whatever else you may think about them, and if you stay bare bones, are just dead simple. And no matter how long your build takes, six months, a year, or whatever, you'll enjoy the process. Every little advance is a victory and a reason to open a beer, and believe me, the first time you fire it up you'll **** yourself.

Yesterday I was coming home from our annual work picnic with a chick in her cage following me who wanted to continue the party. So I handed her my GoPro and she got this. Nothing to do with the above but cool nonetheless . . . Lol.

 

I built an iron head rigid from frame up about 5 years ago so I know the satisfaction of it, I'm stoked for this build, should take me about 6 months