Seat posts might seem to do very little, but there 's a lot to consider when you purchase one.
Find seat post recommendations here.
Find seat post recommendations here.
A seat post is the pipe that connects your saddle to the frame.
There are quite a few things to look out for when choosing one.
Light weight
The seat post should be light. Carbon fiber is unsurprisingly the lightest material for the job, but is prone to cracking if slightly over tightened. Torque wrenches can't always be trusted, so use some carbon friction paste and tighten the bolt gently.
Alloy seat posts are heavier, but cost less.
Sizing
Most road frames require round seat posts with diameters of 31.6mm or 27.2mm although many other sizes are in use. The post length may be between 300-400cm. Choose the length you require so there isn't excess material inside the seat post.
Some frames require a custom seat post, and some even do not require a seat post at all, as the frame has an integrated seat post which needs to be cut specifically to the rider. Such frames might look quite racy, but won't fit in a normal bike box, which makes trips abroad more difficult.
Set back
This is the distance the clamp is placed behind the post and typically ranges from zero to 25mm. Taller riders will usually want set back, but shorter riders or time trialists will prefer to be placed more forward. The time trialists are rotated forward on the bike, so require this more forward position.
Adjustability
All posts allow for fore, aft and tilt adjustment.
The tilt adjustment needs to be very finely tuned so that the saddle is in the perfect position for comfort. Some seat posts have a serrated interface between the post and the clamp, which means that only set tilt adjustments can be made. This will cause difficulty with saddle positioning as the saddle points too far up or down. Such posts designs should be avoided.
Selle Italia has designed a new type of clamp called the Monolink. It allows for more fore-aft adjustment than before. Since fore-aft adjustment was never an issue with most riders, the solution may be redundant, but it certainly looks nice.
Vibration damping
Carbon posts absorb road vibration better than alloy posts, which is a good enough reason to get one. Thinner posts absorb better than thick posts. Some manufacturers have placed rubber dampers in the post to aid comfort, but such items seem to be a gimmick.
Reliability
Surprisingly there is quite a range of seat post strength. At the bottom of the list come the fake seatposts which you can get from Hong Kong sellers on ebay. At the top come alloy posts, with their weight penalty.
The weaker posts tend to crack when tightened or when the rider hits a bump. Around four times the rider's body weight can be transmitted through the post at this time.
Matching post, stem and bars
For a pleasing asthetic, the seatpost should match the stem and handlebars. This is also known as the finishing kit. Most component manufacturers make these parts and market them together.
Price
Last of all we come to price. A good carbon post will set you back around $200 but it is worth it, as this part tends to last a long time.
Popular Brands
3T beautiful looking carbon seatposts. The 3T Palladio LTD carbon post failed in the Tour test. A friend of mine bought a 3T Stylus LTD carbon seat post and it broke at the clamp, and he is very careful with using a torque wrench. Perhaps, then, too delicate?
FSA
The K-Force is in use by the Cannondale Team but this post cracked in the Tour magazine test, and a Titanium bolt failed. This post looks good but the reliability is questionable.
Pro
Another popular post as used in the peloton, since Pro is just an arm of Shimano. The Pro Vibe is an excellent post that is light, looks good and strong, but is fiddly to assemble.
Ritchey
Another pro team favorite. The WCS carbon posts are easy to adjust as there is a clamp for each rail and the saddle angle can be adjusted infinitely. The posts are strong, look good and light. You can even get them on sale at rock bottom prices.
Pieter's recommendedation
I recommend the Ritchey Superlogic carbon 1-bolt seat post, at 148g but this is expensive. For similar beauty, at only 185g, look at the Ritchey WCS carbon 1-bolt post.
These work well with the WCS 260 stem and bars. These components are easy to adjust, reasonably priced, look great, light and durable. Hats off to the Ritchey engineering team.
If you don't fancy Ritchey, then look at PRO. The equipment is of high quality and design - light, strong but of course not cheap, but reasonably priced. The PRO finishing kits are in good use through the pro peloton, so are tried and tested.
Links