I'll add my ignorant question

What are you making? A spring supported suspension type of seat post?

I bought a spring loaded post for my bike seat, the post was to big to fit the tube on my bike.

Mikek

I ride "road bikes" but did try a friend's MTB with a sprung seat tube. It felt sort of "strange" I thought. But then, I think rear suspension feels sort of strange :-)

I herniated a couple of discs in my lower back, I have hit a few bad bumps and wished I had some suspension. I don't notice the spring action until I hit a bump, which I searched out yesterday while I was testing. I had to fight the habit to lift off the seat when I hit a bump, while testing. I've had the bike about 3 months, still trying to find enough time to ride, I've had 50 mile weeks, but usually more like twenty. Getting dark at 5pm, the holidays and rain have slowed me, The days are getting longer, the holidays are past, maybe the rain will cooperate and I can get back to some longer rides. Mikek

While road and weather conditions vary a great deal I do try for a long ride on Sundays and a shorter one on Wednesday. But we don't have snow here :-)

No snow here in FL. either, but we hit 34* last night and 33* is predicted tonight. Mikek