
Different bikes sometimes have different seatpost diameters. The ShockStop Suspension Seatpost comes in 27.2mm, 30.4mm, 30.9mm, and 31.6mm diameters, so if your bike's seatpost is a different size, you'll need a shim to allow the 27.2mm or 31.6mm size to adapt to your bike's frame. Don't worry though, the shims are super-lightweight and essentially invisible once installed.

Not sure what size seatpost you have currently? There are a couple different ways to find out.
• 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.
• If you know the make, model, and year of your bike, you may be able to look up the seatpost diameter online. Feel free to shoot us an email at info@redshiftsports.com - we'll see if we can help out.
• Ask your local bike shop - they'll be able to accurately measure your bike's seatpost.
Non-compatible posts: Unfortunately, if your bike's seatpost is smaller than 27.2mm (for example, the 25.4mm posts found on some recent model Cannondale Synapses) our seatpost is currently not compatible with your bike. Likewise, if you have a bike with an aero/oval/non-round seatpost, or if your bike has an integrated seatmast, the seatpost is also not compatible.
What length should I choose? 280mm, 350mm, 400mm or 450mm?
350mm is our standard size, but we added the 280, 400, 450mm to allow for a wider range of fits. Measure your current seatpost from the clamp collar to the saddle rail:
- If that distance is less than 205mm, you can use the 280mm suspension seatpost.
- If it is between 205mm and 250/275mm (depending on diameter) order the 350mm size.
- If it is between 250 (larger diameters than 27.2) and 300mm order the 400mm size.
- If it is between 300 (larger diameters than 27.2) and 350mm order the 450mm size.

Smooth. Controlled. Effortless. The Future of Suspension
Years of research, cutting-edge technology, and rider-focused design—built to revolutionise your ride.
Adjustable Stiffness
Fine-tune your ride with customizable settings, optimising comfort and performance for any terrain.
Precision-Engineered Shock Absorption
Eliminates road buzz and dampens impact forces, reducing strain on hands, wrists, shoulders and back.
Optimised for All Riding Styles
Whether you're racing, exploring or commuting, we have an option that is designed to improve your riding experience.
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Great support, no fuss, high quality
High quality seat suspension. Never had tried anything else like it. Makes my 40mi gravel rides feel like 15mi. Needed for a day of old man Randonneuring. Worth it.
Rockin on a Redshiftlad got onue yo will be to.
Easy to install and easy on you when you hit the bumps .
Game changer
Outils indispensable sur un hardtail et si on souhaite faire de l’endurance sur des terrains techniques ou juste avoir du confort
Amazing
This thing is awesome. Makes the ride so much smother. We'll worth the money.
Seatpost Boingie Thing
It’s strong. Hold seat up when the bike is vertical. Goes boingie in a very non-threatening way. Butt has fallen in love with it. Will not kick it off the bike for eating crackers!










