Butt discomfort is a common complaint among cyclists, caused at least in part by road vibrations being transmitted up the frame and into the saddle. As a result, we've seen a number of suspension seatposts and cushy saddles being introduced over the years. The Rinsten Spring takes another approach yet, in the form of a steel spring that's installed between the saddle and seatpost. I recently got to try one out, on my local potholey streets.
Installing the 392-gram Rinsten Spring is a little fiddly, but it's nothing you can't manage if you already know how to mount the saddle directly on the seatpost. No special tools are required, and it only took me several minutes.
The extra height of the device does mean that the seatpost will have to be lowered accordingly. This provided a bit of a challenge in the case of the fatbike I was using, as the seatpost couldn't slide down past the point where the seat tube joined the down tube – fortunately, I was able to get it just low enough. On a lankier-framed road bike, that shouldn't be a problem, but it's still something to be aware of.
Setting the tension is achieved by altering the points at which the saddle and seatpost are attached to the spring – moving those points closer to the front of the spring makes it less bouncy. After some experimentation, I determined that I preferred it at the highest tension. For my weight and riding preferences, having it set much lower felt like riding on a beach ball.
Even at the optimum setting, the Rinsten Spring still does take some getting used to. It moves as you pedal, initially making the bike feel kind of squishy. Indeed, serious road racers who like a really stiff, efficient ride may not take to it at all. Also, unlike a mountain bike shock absorber, it has no rebound adjustment, so it does noticeably spring back up after compressing when hitting bigger bumps.
Still, it does definitely smooth out the ride in quite a simple manner, so cyclists such as commuters and long-distance tourists may want to give it a try. It's currently the subject of a Kickstarter campaign, where a pledge of US$28 will get you one, when and if it reaches production. The planned retail price is $50.
It can be seen in action, in the video below.