SP-S4 Suspension Seat Post
Upgrade your riding comfort with the SP-S4 Suspension Seat Post. Designed with a mechanical linkage suspension system and an internal stainless-steel spring, it helps absorb road vibration and impacts from uneven surfaces for a smoother and more comfortable riding experience.
Available in three common seatpost diameters — 27.2 mm, 30.9 mm and 31.6 mm — the SP-S4 is suitable for a wide range of bicycles and e-bikes.
Key Features
50 mm suspension travel
Adjustable suspension stiffness
Aluminum alloy construction
Internal stainless-steel suspension spring
350 mm seatpost length
Three diameter options: 27.2 / 30.9 / 31.6 mm
Adjustable saddle position
Clearly marked minimum insertion line
Suitable for bicycles and e-bikes
Designed for commuting, touring and everyday riding
50 mm Suspension Travel
The SP-S4 suspension structure provides up to 50 mm of shock-absorbing travel, helping reduce impacts transmitted from rough roads, small bumps and uneven surfaces to the rider.
The linkage suspension design allows the saddle to move in a controlled way when encountering road vibration, helping improve comfort during longer rides.
Ideal for:
- Urban commuting
- Bike paths
- Touring
- E-bike riding
- Gravel and uneven roads
- Daily recreational cycling
Adjustable Suspension Stiffness
The suspension preload can be adjusted according to rider weight, road conditions and personal riding preference.
Use a 6 mm hex wrench at the bottom of the seatpost to adjust the spring preload.
Turn toward:
“+” → Firmer suspension
“–” → Softer suspension
This allows riders to customize the suspension response for a more comfortable and controlled riding experience.
Stainless-Steel Suspension Spring
The SP-S4 uses an internal stainless-steel spring as part of its suspension system.
The spring works together with the linkage structure to help absorb vibration and impacts while maintaining stable support during riding.
Benefits
- Stable suspension response
- Reduced road vibration
- Low-noise operation
- Durable internal structure
- Suitable for repeated everyday use
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Aluminum Alloy Construction
The main seatpost body is manufactured from aluminum alloy with a matte surface finish.
It provides a balance between structural strength, durability and everyday riding performance.
Features
- Aluminum alloy construction
- CNC-machined components
- Matte surface finish
- Wear resistant
- Corrosion resistant
- Designed for long-term bicycle use
Available Sizes
The SP-S4 is available in three seatpost diameters:
27.2 mm × 350 mm
30.9 mm × 350 mm
31.6 mm × 350 mm
Please check the diameter marking on your original seatpost or measure the inside diameter of the bicycle seat tube / outside diameter of the existing seatpost before ordering.
Choosing the correct diameter is essential for safe installation.
Product Dimensions
27.2 mm Version
Diameter: 27.2 mm
Length: 350 mm
Lower Tube Length: 240 mm
Suspension Head Height: Approx. 80 mm
Weight: Approx. 850 g
30.9 mm Version
Diameter: 30.9 mm
Length: 350 mm
Lower Tube Length: 240 mm
Suspension Head Height: Approx. 80 mm
Weight: Approx. 923 g
31.6 mm Version
Diameter: 31.6 mm
Length: 350 mm
Lower Tube Length: 240 mm
Suspension Head Height: Approx. 80 mm
Weight: Approx. 942 g
Measurements and weight may have small production tolerances.
Safe Installation Range
For safe installation, always observe the MINIMUM INSERT mark printed on the seatpost.
The seatpost must be inserted into the bicycle frame beyond the minimum insertion line.
Do not install the seatpost above the permitted minimum insertion marking.
Reference Dimensions
Adjustment / exposed range: approximately 140 mm
Minimum insertion section: approximately 75 mm
Always confirm that the seatpost is securely clamped before riding.
Adjustable Saddle Position
The upper saddle clamp allows the saddle position and angle to be adjusted to suit the rider's preferred riding posture.
Before riding, make sure all saddle clamp bolts are correctly tightened.
The saddle clamp shown on the product is compatible with standard bicycle saddle rails.
Suspension Linkage Design
The multi-link suspension structure allows the seatpost head to move under load while keeping the seatpost body securely installed inside the bicycle frame.
Multiple pivot points help guide the movement of the suspension system and provide controlled shock absorption.
Product Specifications
Model: SP-S4
Product Type: Bicycle Suspension Seat Post
Color: Black
Material: Aluminum Alloy
Suspension: Mechanical Spring Suspension
Spring Material: Stainless Steel
Suspension Travel: Approx. 50 mm
Seatpost Length: 350 mm
Tube Length: Approx. 240 mm
Suspension Head Height: Approx. 80 mm
Available Diameters: 27.2 mm / 30.9 mm / 31.6 mm
Adjustment Tool: 6 mm Hex Wrench
27.2 mm Weight: Approx. 850 g
30.9 mm Weight: Approx. 923 g
31.6 mm Weight: Approx. 942 g
Application: Bicycle / E-Bike / Commuter Bike / Touring Bike
Important Size Notice
Please confirm your bicycle seatpost diameter before purchasing.
27.2 mm, 30.9 mm and 31.6 mm are different sizes and are not interchangeable without a suitable adapter.
Check the diameter printed on your existing seatpost whenever possible.
Do not select a size based only on the bicycle brand, wheel diameter or appearance.
Installation & Safety Notes
- Confirm the correct seatpost diameter before installation.
- Insert the seatpost beyond the MINIMUM INSERT line.
- Securely tighten the bicycle seatpost clamp before riding.
- Securely tighten the saddle clamp bolts.
- Adjust spring preload using a 6 mm hex wrench when necessary.
- Check all bolts periodically, especially after the first few rides.
- Stop using the product if abnormal movement, looseness or damage is detected.
Package Includes
1 × SP-S4 Suspension Seat Post
Bicycle saddle and installation tools are not included unless specifically stated in the selected package.