came across this devise this morning while taking a break in-between shoveling heavy snow .. https://rinsten.com/

There’s at least one here who’ve used one of those. He ended up pre-loading his and maybe some other tweaks before he was content.

Clever idea in that it can simply replace the saddle in the seat post and it is adjustable for pre-load. My only concern is concentrating so much force is such a small bending area. The springs on a Brooks Flier, for example, spreads the bend out over, probably 12 inches, if we were to take a spring off the saddle and unwind it. I will guess that this bending area is about 3-4".

I'm interested in hearing reviews.

i would like to use my brooks flyer on a build i'm doing, but when i pick it up and heft it in my hand.. wow, it's so heavy. i used the flyer on an ebike and it was very nice, but weight wasn't an issue with that bike.
the risten spring weighs in at 337grams plus the weight of whatever saddle you use. i think the brooks flyer was around 860. so 6 of one, half a dozen of the other....

I can come up with lower risk parts for $60.

Looks bouncy.

At least one bikeforums member had one and it broke.
Thread with pics of broken: Rinsten saddle spring

From an engineering standpoint, I don't think it's a very good idea. There's no dampening, so the rider looks to bounce up and down quite a bit. You can see this even in their promotional video. And holy cow, they are expensive! For the price, why not go for a more proven, less bouncy, and possibly even lighter weight, elastomer-based suspension seatpost?

Turn any saddle into a cruiser saddle? If you're not using a French fit, I guess it'd be fine.

I've never seen or heard about these things.
It's sort of a stealth mini-beam design.
I'd love to see a saddle forces comparison of this product, suspension seat posts, and beam bikes (i.e. TREK Y-Foil, Softride, and Zipp).

If that is well designed and used within its limits, it looks like a great idea - for some people and for some situations. Yes, it is not damped. That can be good or bad. I wouldn't want it on the road but if I went back to riding gravel, it might be a real asset for me. (I have NFLoffensive lineman-like "loose brain syndrome". My made up term but all of those linemen would get instantly what I an talking about.)

Like anything - there is the engineering tradeoffs of strength, weight, cost and reliability. Once built and out there, someone will find a way to break it. At 150 pounds, I could probably abuse that for years. I've broken ti saddle rails but that was due to slamming the seat so far back the clamp was at the rail turn. Ride ender but otherwise no that big a deal. Now, using that device to do BMX style jumps on your road bike? Maybe not a good idea.

Almost looks too logical.
Which means it was likely tried long ago, and was not adopted as a design.

No, thank you. I weigh 255lbs. Bad things would happen eventually. Very bad things.

I used something similar for a couple years on my folding bike. I don't remember what it was called, but it was a similar design plus elastomers or something to dampen the bounce. I used thus because it raised my seat another couple inches, which was good. I didn't notice whether it improved the ride in any way until one day it became very bumpy. Thats when I realized the elastomers had cracked up and gone AWOL.

This thing may work for some riders, but it's a lot of money for a piece of steel wire.

Looking at it, all I can see is how much further down the seat post is going to be in the seat tube and how crappy it will look as a result.

Yeah, I'd stick with coil springs. Less risk of failure, less risk of consequences of any failure. If I still weighed north of 200 lbs I might trust a U-spring made from flat steel stock, although it would be heavier. I'm down to 150 lbs now so that
Rinsten spring might hold up okay.

The ride will be bouncy and pedaling less efficient. But sometimes that's a fair trade off for comfort. My first bike when I resumed cycling in 2015 was a comfort hybrid with thickly padded saddle with coil springs. I needed it to gradually improve my fitness while recovering from neck and back injuries.

And my main hybrid has a thickly padded saddle without springs. It still feels very bouncy compared with my road bikes with minimalist rigid saddles. But it's still very comfortable for casual rides when I'm not looking for a workout.

Power sucker. Every time you push a pedal you go up = power loss and for what? A bouncy ride? Not for this little black duck!

I would not want it to be my gooch when that thing decides to give way....

Bet it takes a long time to mess with that post re-locating to get a proper setup, too.

Kinda reminds me of this:



DD

The whole idea reminds me of the springs under the seat on my old John Deere garden tractor, which had two huge 2" U shaped springs on which the seat pan attached.
They looked like two truck springs bent in a U shape. They would last a couple of years then either sag or snap at the bend. After replacing the third set I found a couple of huge valve springs from an old engine to add support to rear end of each spring and they lasted for another 10 years.

I could picture a set up like that on a bike could lead to a pretty nasty injury when it fails, and find it really hard to believe that a small round piece of steel like that would have any longevity as a spring that could be supporting a couple of hundred pounds. The likely hood of metal fatigue early on would be pretty high.

In a coil spring, the stresses are spread over the entire coil and each coil moves very little, on that seat spring, all the flex is concentrated in one area and movement is concentrated in one area.and that's bound to fatigue and fail.

There are a couple different brands of these available on Amazon for under $30.

A sprung saddle seems like a better option, and plenty of those out there.

Is that made by Acme? Seems a little too gimmicky and a potential recipe for skewered oysters.

Just ride the Flyer. I have three or four.
Weight difference not much more than a few bottles or water.