Seatpost

The saddle support is a bicycle or a moped, a tube made of steel, aluminum or carbon fiber reinforced plastic, which supports the saddle with a clamping mechanism and is used for the height adjustment. Modern Carbon Stattelstützen partly under 100 g, aluminum supports between 200-300 g, steel seatpost weigh usually about 500 g

Fixation

The seat post is inserted and fixed in the seat tube. This diameter seatpost and seat tube must match. Spreads are 27.2 mm for racing bikes and 31.6 mm for mountain bikes. But there are many other dimensions.

In order to fix the seat tube a clip at the top of the seat tube is integrated at affordable wheels. In high-quality bicycles a separate terminal will be used. Such terminals are available with screw and quick release that allows quick height adjustment of the saddle. This comes in handy especially with rental bikes. For mountain bikes a terminal is almost always used with quick release to lower the saddle on steep climbs and continue to shift the body so backwards can, which in turn should prevent falls forward. There are also seat posts, the lower the push of a button and let it back up again. The biggest drawback of the quick release is that the seatpost including saddle can be easily stolen. There are also terminals with a screw with a specially shaped head to prevent theft.

Saddle candle

A saddle candle is a piece tube made of steel or aluminum with a top standard taper from 22 mm to accommodate the Sattelklobens. This taper may abort with fatal consequences if the metal edge of block intersects by repeated rotary motion into the material. Saddle candles were up in the 1990s, the standard saddle attachment. The tube diameter was 25.4 mm mostly.

Patent Seatposts

What is special about patent seatpost is the integration of the saddle clamping mechanism in the head of the seatpost, which usually have a more robust connection from the saddle to the support is achieved than with the previously common, multi-part fasteners made of sheet metal, which connected the saddle candle to the frame of the saddle.

To attach the saddle to the seat post, there are numerous different designs. Many of the saddle is fixed with only a single ( Allen ) screw. Differences, particularly relating to the nature of the angular displacement of the saddle. In part, only coarse locking stages are present, other seatposts allow continuous adjustment. Ideally, the clamping of the seat can be performed independently of the angle adjustment so that the inclination of the seat can be varied, without moving it inadvertently and vice versa. Listed at the top of the seat post clamp bolt next to the larger two smaller allen screws, it can be usually set the inclination of the seat by out - and the other turns into one of these screws equally.

In the early 1990s oval or teardrop-shaped patent seatposts were introduced on the grounds of the lower air resistance. The point is controversial, since these seatposts usually have a higher weight.

Sprung seatpost

Sprung seatpost can be used as an alternative to the rear suspension. Compared to a suspension frames they have the disadvantage that the distance from the pedal changed to the saddle. Moreover, the unsprung mass is greater, resulting in a worse response. However, this does not matter much at the usual, relatively short suspension travel of 40 to 50 mm. With proper adjustment of the spring force, the saddle when sitting the driver lowers already almost from the half of the stroke, so that there is only a change in the seat height by 20 mm while driving up to 30 mm. Any type of suspension decreases the voltage peaks acting on the bicycle and extends to some extent as the service life of the material. By a spring, on the other hand, the number of moving parts increases the cycle, which must be maintained and replaced in case of wear or breakage.

In addition to the gain in comfort improve forks and suspension rear stays the grip of the wheels, thereby increasing the safety and allow higher speeds in rough terrain. However, this can not afford a suspension seatpost in general. My purpose is rather to increase the convenience, which enables particularly on longer journeys a much more relaxed, pain-free and perennial pedaling. Even a simple suspension seatpost short travel makes driving on uneven ground noticeably more pleasant.

The saddle of a bicycle suspension should be set a few inches higher to compensate for the deflection of the wheel when sitting the driver. This can temporarily lead to uncertainty in untrained cyclists during ascent.

In simple spring-loaded seat posts a thinner tube is immersed during compression in the actual seat post. Due to the reduced cross-section seatpost, which were made ​​of too soft material can break at the top. Technically more elaborate seatpost lead the saddle during compression not only down, but a parallelogram also backwards so that the seat height while driving not changed much.

A suspension can swallow by friction and attenuation of up to 20 percent of marketed by the driver on the pedal power. Therefore, the proportion of energy which has to be applied on uneven ground to the deformation of the other components of the wheel decreases. The more uniform and more relaxed driving style a suspension can generally lead to improved energy consumption.

An alternative to sprung saddle support, the use of wide tires is (e.g. in the size 2 "to 2.5 ", which corresponds to a width of 50 to 65 mm), to a relatively low air pressure of 1.8 2.5 can be run bar. This is common despite the resulting increased rolling resistance, for example in mountain bikes, which are moved in the terrain, since at low air pressure, the traction on uneven, slippery, unpaved and muddy ground increased. Introduced at the beginning of the millennium tubeless installation of bicycle tires even allows an even lower air pressure.

Vario seatposts

Vario seat post can be adjusted while driving in height. For this purpose, the driver presses a lever under the saddle or a button on the handlebars. The weight on the saddle pushes him down without weight, the saddle is moved upward (similar adjusting the height of an office chair ). There are models with continuously adjustable and with two or more stages.

Special shapes

Radballräder have a special, horizontal seat post.

Problems with the seat post

Steel frame with threaded slots

With inexpensive wheels the post is secured with a normal steel screw that holds in a groove. If the groove is worn or the screw was tightened too much, it will be crooked and no longer holds, you can not really fix the rest. Fix the problem creates a new screw, usually has to serve a double - screw ( expensive ) to fix the seatpost safely. Even a gentle rubbing with an adjustable reamer can remedy the situation - this is to be set very accurately and carefully. Retractable ferrules represent another stopgap

Patent supports in the form of drops

This can break without warning in the head. For heavy riders, track bikes or touring bikes can be a known sailing boats turnbuckle in reverse operation mounted under the nose of the saddle. The other end of the rigging screw holds the top tube of the frame and prevents breakage of the seat post.

Security risk in incorrect assembly

Seatposts usually have a design-related, marked on the minimum pipe length, with which they must be inserted into the seat tube. This mark must not be seen with built-in seat post, otherwise the rest is clamped too short. Even among drivers with " normal weight " then the lever forces (bending ) is too large; the material of the tube is overloaded, is tiring and can break off just above the seat clamp - with the risk of a fall.

Missing the mark on a seatpost, one can roughly assume that at least 65 mm seatpost must be pinched in the seat tube.

Should the saddle be set ( when children are too big for the child's bike or adult people with great body length and correspondingly long legs want to drive "normal" bikes), is strongly recommended, not just "put up " just by pulling the seat post. You can remedy in these cases only by another, according to running longer and stronger seatpost - or better yet by another bike with larger frame size ( longer seat tube).