REDSHIFT ShockStop Suspension Seatpost for Bicycles

Product Information

The Cirrus KINEKT 2.1 is an aluminum suspension seatpost that’s designed to isolate your body from surface vibrations and impacts to improve comfort and control. Each post comes with two extra springs so you can mix and match, creating a custom experience. The KINEKT post springs are available in five color-coded tensions for riders ranging from 50-320 pounds. I *think* my knees are happier for getting rid of the suspension seatpost also, it seemed to be aggravating some ITB syndrome or something in my left knee, but perhaps I just never got the saddle position right. Deflection is the total movement that a seatpost will move after an impact. A seatpost with more deflection will reduce the fatigue on your body as it protects you from harder jolts like unexpected potholes or dirt road corrugations. It’ll also allow you to keep pedalling through particularly bumpy terrain. Once underway on my favourite gravel test loops, it was hard to detect any movement from this seatpost – there’s no bobbing sensation to distract from the ride. It wasn’t until I reached down and placed a finger against the side of the seatpost that I detected its subtle flex. I’ve run it on both a rigid gravel bike and on a bike with a (gravel) suspension fork, and the effect on both was transformative.

Most seatposts have the diameter printed somewhere near the bottom of the post. You'll need to remove the seatpost from the bike frame (mark your existing seatpost height with a bit of tape before you remove it so you can replace it easily), and look for a number like 27.2, 30.9, or 31.6 (etc.). That is the diameter of the post. In the end, I can say that 90% of the time I did not even feel the suspension doing its job (although it definitely was moving when I was looking at it). There was also no bounciness when pedaling hard. Krzysztof over at GravelBikes.cc has been using his smartphone with a vibration meter app to compare the vibration absorption of different bike components on both a bumpy forest trail and fast gravel road. Once you determine the length of your existing stem round to the nearest 10 mm and choose the closest match.On bigger bumps, there was still a lot of saddle movement up and down, so I adjusted the firmness a touch more (level 3 for 100kg riders). Another test ride and the feeling was even better. Our first impression is that there is significantly less dynamic movement when compared to the original version. Since there was no need to set the sag, there is also very little upstroke like you would get on the original if you opted for a lot of sag. Honestly, the Pro post feels much more supportive and natural. There is definitely movement, and you feel it immediately, but it’s not as overwhelming. The stroke is also very progressive, so small bumps and vibrations are muted but the larger impacts are still felt. A plastic, magnetically secured fender can be removed to drop about 9 grams but is meant to keep dirt out of the linkage.

mm is common on older road bikes with drop handlebars. - There are other less common sizes that we do not provide shims for. However, other handlebar shim sizes may be available at your local bike shop. It’s available to fit 27.2, 30.9, 31.6 seat tubes, uses USE's Duro single-bolt clamp and the post is fully serviceable. The post and head are machined from aluminium. The 27.2mm post weighs a claimed 455g.

The saddle angle is retained throughout the cycle of travel, this is most certainly important given the amount of vertical compliance; should the front of your saddle suddenly gain 35mm more height than the rear you’d no doubt be looking discomfort in the face. Mine was bushings, even with the little bits of space around the elastomer all filled in with bar tape off-cuts it would still happen. I must say, although the bumpy forest route was delivering huge comfort improvements, I think the Redshift suspension seatpost performs best on fast gravel roads with a lot of high-frequency vibration. You don’t really notice the suspension working underneath, and you don’t feel any bounciness either.