For most eBike riders, choosing a quality, well-fitting saddle is enough to ensure comfort on longer rides. Your body will also physically adapt to sitting on the saddle over time, which further helps with comfort. But for some riders who have trouble getting comfortable even with consistent riding, a suspension seatpost may help.
A suspension seatpost pivots, slides, or flexes, allowing it to absorb vibrations and road shock from bumpy surfaces, which can be a nice upgrade for modern eBikes. Let's review who should consider adding a suspension seatpost to their eBike, and how to shop for one.
Which eBikes can accept a suspension seatpost?
If you're considering adding a suspension seatpost to your eBike, there are a few things to consider first:
- The seat tube and seatpost on your eBike must be round. The vast majority of eBikes use a round, circular interface, but if your eBike has a proprietary shape (like an aerodynamic oval or wing shaped seatpost) it might not be possible to add a suspension seatpost at all.
- Suspension seatposts slightly increase the minimum saddle height on your bicycle, because the mechanism takes up some additional vertical space. This means you might not be able to lower the saddle as much. This isn't a big deal for taller riders, but if you're already riding with the saddle height in a very low position (close to the top of the frame) it might not be possible to add a suspension seatpost while maintaining the same saddle height.
- Suspension seatposts make the most sense on hardtail bicycle frames. If you're already riding a full-suspension frame, adding a suspension seatpost won't change much from a comfort perspective, because you already have rear suspension travel.
- Suspension seatposts are more complex than plain rigid posts, which makes your eBike heavier. Consider that eBikes are already heavier than their analog "cousins", so make sure the additional comfort is worth the trade-off for your needs. Suspension seatposts also add additional complexity compared to a simple, reliable rigid seatpost.
Finally, a special note about folding eBikes. Many folding models use a "telescoping" seatpost that can collapse down to save space while still extending to the proper height for efficient pedaling. Other folding models use a seatpost that doesn't telescope, but instead is just incredibly long, way longer than any normal seatpost. If you have one of these models, it may not be possible to add a suspension seatpost, because they simply aren't offered in these styles.
How to choose a suspension seatpost
To swap seatposts on your eBike, the diameter of the replacement must match exactly. There are several common diameters in use today, with differences too small to be seen by the naked eye - for example, 30.8mm and 30.9mm. You can't accurately measure a difference of one-tenth of one millimeter with a tape measure or ruler, yet even that .1mm difference will prevent the replacement post from working properly! So make sure you purchase an exact match.
For this reason, seatposts are typically stamped with their size for easy reference. If you remove your seatpost you'll usually find the size stamped near the minimum insertion mark. The labeling might not always be obvious but is almost always there - a 27.2mm diameter seatpost may be stamped "272", for example, while "316" indicates a 31.6mm diameter.
You'll also want to consider the overall length of the replacement seatpost - they are usually measured from the bottom of the post to the part of the clamp that grabs onto the saddle rails. 300mm, 350mm, and 400mm are common lengths. Compare the length of your existing seatpost and purchase a replacement of the exact same length if possible.
What about the saddle?
With very few exceptions, just about all modern saddles and seatposts interchange because they share the same railed interface. If you purchase a new suspension seatpost, you can reasonably expect that your existing saddle will fit on it.
Using a seatpost shims
It's common for suspension seatposts to only be offerered in a short list of the most common diameters, so you may not find a direct match to the diameter used on your eBike. In this circumstance, a shim can be used.
- Some eBikes use 30.4mm diameter seatposts. You can find a rigid replacement seatpost in 30.4mm, but not a suspension model. In this circumstance, a common 27.2mm suspension seatpost could be used on the 30.4mm diameter eBike by adding a 3.2mm shim to take up the gap.
- Don't try to use a homemade shim - buy one specifically made for bicycle seatposts, such as those made by Problem Solvers or Cane Creek.
How much should I spend?
Suspension seatposts can cost between about $30 for a basic, low-end model, all the way up to $200+ for a higher performance model. More expensive suspension seatposts are lighter (so they won't add too much extra weight to your eBike) and may offer more adjustments to suit the rider's weight and desired amount of movement. Basic models might help take the edge off bumps but lack sophisticated adjustments to fine-tune their performance.
Recommended suspension seatpost models
Cane Creek's eeSilk and Thudbuster models use a parallelogram design with an elastomer bumper. The elastomer can be changed out to suit different rider weights. The Thudbuster is one of the most recognizable suspension seatposts on the market at $199, and for weight-sensitive riders, there's even a carbon fiber model on the eeSilk line at $319.99.
Redshift's ShockStop is a similar design that's become more popular recently at the $229.99 price point. Another less-expensive, but still functional suspension seatpost is the NCX from SunTour, for about $100, which is worth considering for riders on a tigher budget.
Interested in adding a suspension seatpost to your eBike? Chat with the team at Bike.com and we'll walk you through the installation process.