D.2 ST-Ro – Dropper Parallelogram Seatpost

The D.2 ST combines the advantages of the lowerable by,schulz D.1 Seat post, offering maximum riding comfort from the renowned G.2 Parallelogram suspension seat post.
The D.2 ST allows for convenient lowering and raising of the saddle position while riding and when stationary, using a remote lever attached to the handlebars. This allows you to find your perfect driving position. The saddle is lowered or raised by operating the remote lever.

To lower the seat height while riding or when stopping, such as at a traffic light, keep your weight on the seat and operate the remote lever mounted on the handlebars.
To extend the seatpost, lift your body off the seat and operate the remote lever. The seat post will now extend to its maximum height or stop and remain in its current position when you release the lever.
The speed of this function can be controlled by the intensity of the pressure applied to the remote lever. Low pressure causes slow extension, while high pressure causes extension at maximum speed.

The parallelogram suspension of the D.2 ST is progressively designed and reacts sensitively to light impacts and with increasing spring resistance to hard impacts. The parallelogram suspension of the D.2 ST sinks up to 18 mm backward and approx. 22 mm downward under load. Zur optimalen Anpassung an das Fahrergewicht und die Fahrweise, stehen leicht austauschbare Federelemente mit 4 verschiedenen Härtegraden und Dämpfungen zur Auswahl.

Inside the lowerable D.1 / D.2 A high-quality gas pressure spring is installed in the seat posts. This allows you to adjust the saddle height using a remote lever mounted on the handlebars! When the remote lever is actuated, the valve on the gas pressure spring is opened via an internal cable. As a result, the saddle lowers under the weight of the body, or extends further when the weight is removed. Wird der Hebel losgelassen, schließt das Ventil und der Sattel verbleibt in der aktuellen Höhe.

NOTE: Carefully plan the installation and the mounting points for the cable guide. You can use existing mounting points and add additional brackets from an accessory store, or attach the outer shell along existing cable guides using cable ties.
Make sure that the inner cable and the outer shell are long enough for the planned installation route on the frame!
Remove any burrs from the seat tube of the bike. All parts must be clean during installation! Before installation, check that the diameter of the support matches the diameter of the seat tube!

1. The by,schulz D.2 The ST-Ro seat post allows the cables to be routed outside the frame. As a rule, all bicycle frames/e-bike frames are suitable for laying external cable runs.

The cable routing must not be kinked or crushed along its entire length!

Note: Due to the parallelogram mechanism of the suspension, the D.2 ST-Ro has a greater overall height than conventional dropper posts. Check these requirements by measuring your bike as accurately as possible in advance.

With the seat post fully lowered (measurement A), you should still be able to stand securely with your front foot on the ground (regardless of the installation depth of the seat post)!

Is the D.2 If the ST-Ro cannot be fully inserted into the seat tube of the bicycle, we advise against using the seat post in combination with this bicycle frame.

Dimension A – Min. Installation height: approx. 135 mm
Dimension B – Installation height when extended: approx. 215 mm
Dimension C – Required installation depth: approx. 190 mm
Dimension D – Total length when extended: approx. 405 mm

Please also note that the individual height of your saddle must be added for the correct seating position.

Dimensions A, C, and D refer to the center of the saddle clamp. Please note that, depending on the frame for bending the cable routing, approx. 50 mm of additional installation space is required below the D.2. ST-Ro is required!

3. The diameter of the seat tube of your bicycle/e-bike should match that of the seat post. Any reduction sleeves that may be required must have a minimum length of 100 mm and must always be inserted completely into the frame.

If the frame manufacturer provides different specifications regarding the sleeve length, these must be observed. The higher value is then decisive!

4. Check whether the minimum insertion depth of the seat post of 100 mm can be maintained!

This is marked on the rear of the seat post tube (STOP min. insert) below the extension scale. The production serial number is located above the scale.

5. If the frame manufacturer specifies different minimum insertion depths, these must be observed. The higher value is decisive. Failure to observe the minimum insertion depth may result in falls or damage to the seat post and/or frame.

6. The clamping force of the seat post clamp should be 5–6 Nm when securing the seat post in the frame. Exceeding the clamping force values can lead to malfunctions such as reduced immersion or extension speed and damage to components of the D.2. ST-Ro coming.

7. In the case of D.2 ST-Ro comes standard with a saddle clamp for saddle frames with a diameter of 7 mm. Saddle clamps for 8 mm diameters are available if required. Never combine 7 mm clamps with an 8 mm diameter saddle frame, or vice versa.

Note: Saddles with oval saddle frames must not be used in combination with this support!

8. Check that the width of the saddle frame is compatible with the head of the seat post. It must not be less than 36 mm on the inside. There are some saddles (e.g., core leather saddles) that converge too narrowly at the front of the frame and therefore cannot be combined with this support. Such use is not recommended as it can cause permanent damage to the saddle and support.