
Different bikes sometimes have different seatpost diameters. The ShockStop Seatpost is 27.2mm in diameter, so if your bike's seatpost is larger, you'll need a shim to adapt our seatpost 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.
350mm is our standard size, but we developed the 280mm 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 seatpost. If not, order the 350mm size.
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Awesome product, fits where a carbon post won't
This is a great product. I originally looked at a carbon seat post to absorb vibration, but didn't have enough exposed seat post for it to work. With the Shockstop post, all of the compliance is handled in a compact area just below the seat. Unless your seat post is set really low, you should have room for this.
My bike just hurt, so I didn't ride it
I recently purchased the seatpost and stem - both pro versions. They were worth every penny. Prior to installing them I just didn't ride anymore because I didn't want to put my aging body through the repeated abuse of riding the local roads. But now the post and stem do well to absorb the usual road vibrations and shock of bumps. I am back in the saddle again. Go Redshift go.