Every brand seems to have its own take on the saddle clamp design, which usually includes a bolt at the front of the head and another at the rear, although some have just one bolt. Mountain bikes typically have a lower standover height than road bikes, leaving more of the post exposed, so a wider post is preferred to improve strength. 31.6mm seatpost

Best Lightweight Gravel/Road Dropper: FOX Racing Shox Transfer SL 27.2 Performance Elite Dropper Seatpost left), 30.9mm (middle) and 31.6mm (right) seatpost diameters are most common. Kaden Gardener / Our Media You want a seatpost long enough for your height needs on your bike. A seatpost that’s too short can’t can’t be made longer. A seatpost that’s too long, on the other hand, can be cut to be made shorter. Suspension or Damping and 31.6mm are the most common seatpost diameters, with 34.9mm also emerging as a popular size for mountain bikes. 27.2mm seatpost Modern bike seatposts are built from various materials, with alloy and carbon being the two most common. A quality alloy seatposts will boast a lightweight profile, whilst also benefiting from being durable and cost efficient. A high-end carbon post is a necessary component for serious cyclists looking to squeeze every last bit of performance out of their machine. Competitive cyclists needing to precisely adjust their seatpost height on the fly should browse our range of dropper posts.Most saddles have round rails, whereas some have oval rails. You may need a seatpost with a clamp design that’s deeper to accommodate oval rails. The business end of the seatpost is its head, which has a clamp mechanism to attach it to the saddle rails. If you want to fit a thinner seatpost to your bike, you can buy shims that fit between the frame tubing and the seatpost. You can’t fit a wider seatpost than that your bike is designed for. Seatpost length ranges anywhere from around 75mm to more than 400mm, though most posts come in lengths between 300mm and 400mm.

It’s usually made of metal, even in a seatpost with a carbon shaft, although some carbon seatposts are one-piece and include a carbon head. If it has a round seatpost, however, you are likely to have far more options – but diameter becomes all-important. The two standard diameters are 27.2mm and 31.6mm and all of the seatposts featured in the guide will fit one of those two sizes, while some have more options in between.

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There are varying degrees of complexity in getting the clamp set up and adjusted properly, from slightly awkward to downright infuriating. Some seatposts, particularly those for road bikes, try to add in some sort of suspension or damping mechanism to reduce the amount of vibration that reaches the saddle—and ultimately, your rump. Some of these are passive, relying on the materials in the seatpost, while others are active, with joints, springs, and pistons. Dropper Mechanism The seatpost is one of the most important parts of your bicycle. A good seatpost supports the majority of your weight on the bike and must be able to withstand that weight while maintaining the appropriate angle for your ride and without moving. While the seatpost your bike comes with is likely adequate for the job at hand, for those looking to upgrade their kit or replace one that broke, a new seatpost offers an opportunity to cut weight and even add some suspension to reduce vibration, making it easier to ride farther. Best Bike Seatposts Some bikes even go as narrow as 25.4mm, Cannondale being a case in point. A skinnier post will provide a bit more flex, and therefore a slightly more comfortable ride, while a fatter one will be more robust and add stiffness for additional power transfer.

For a dropper post to work, there needs to be sufficient space in the frame’s seat tube. This is particularly an issue with smaller frame sizes, which often have shorter-travel dropper posts as a result. The longer seatpost length of mountain bikes means rigidity and robustness are important, whereas with the shorter seatposts on road bikes, compliance and ride comfort are greater priorities. 34.9mm seatpost As with all aerodynamic upgrades in cycling, it is a culmination of marginal gains that will start to make noticeable differences to your riding. So, yes, seatposts can make a difference but, in most cases, aero seatposts will come in a proprietary design to fit a specific bike, making upgrade options considerably limited. Do carbon seatposts make a difference? Like handlebars, wheels, and nearly all other bike components, seatposts come in a variety of materials, the most common being aluminium and carbon fibre. As always, carbon commands a higher price tag, but it usually weighs less and can be constructed in a way that dampens more vibration while maintaining directional stiffness in a way that will benefit the rider.The introduction of carbon to bike manufacturing was a game changer for seatposts. Not only can it help to reduce the overall weight of the bike, but the way in which carbon components are manufactured – by building up layers of fibres –can be adjusted to give it the perfect blend of compliance and stiffness. From damping to deflection, the best carbon seatposts can help soften vibrations and take the edge off impacts. Most dropper posts enable you to lower your saddle by between 125mm and 170mm, while outliers start at 100mm and go as high as 210mm. Finance is subject to application, financial circumstances and borrowing history. Performance Cycling Limited FRN: 720557 trading as Tredz are authorised and regulated by the Financial Conduct Authority. We are a credit broker not a lender – credit is subject to status and affordability and is provided by Mitsubishi HC Capital UK PLC. Terms & Conditions Apply. Most seatposts follow the same design principles, with a hollow tube constructed from aluminium or carbon fibre - onto the top of which the seat sits. Variations available in standard format includes seatpost diameter, seatpost length, as well as the aforementioned materials, and finally the clamp type.

Most of the best road bike saddles use a two-rail system, however not all two-rail saddles are compatible with all seatposts. Saddles with alloy rails will have 7mm, round rails, while most carbon-railed saddles have 7x9mm oval rails. Round seatposts come in several different diameters, to fit in different-sized seat tubes. If you’re changing your seatpost, make sure the post you’re replacing it with is the correct diameter.Road and gravel bikes tend to have a longer seat tube than mountain bikes, so usually requirer a shorter post of around 300 to 350mm. Mountain bikes typically leave more of the seatpost exposed above the frame, so require a longer post.