TECHNICAL > SHOCK ABSORBER

THE COMPARISION BETWEEN MONOTUBE AND DOUBLETUBE

1. Mono-tube design vs. double-tube design

Mono-tube construction is a tube which is separated into two parts, oil and gas. With piston movement in the tube, damping force will occur. There is high air pressure in the strut and certain load capacity; as the result, it could remain its damping force. Please see picture shown on the left side. There are a variety of advantages for mono-tube design. It contains higher rigidity, longer durability and ease surely. The damping force will be more stable on a bumpy road. Because of higher rigidity and fineness, professional manufacture technique is needed to manufacture mono-tube strut.

Double-tube design is made by double oil tube construction and oil will flow between inside and outside with strut movement. Comparing with mono-tube design, the oil capacity and the pressed area of double-tube design is smaller so that it is difficult to adjust slight dampening force. Besides, by reason of double tube, the radiation is worse and oil deteriorates easily. From the point of working, the cost of double-tube design is lower than mono-tube one. Generally, the manufacturer who produces a large amount of OE parts will produce double-tube design.

2. Piston Diameter, Valve, and The Hole of Oil Flow

Comparing with double-tube design, the piston area and the valve diameter in mono-tube are bigger and piston hole is improved. Therefore, mono-tube design could manage gravel road perfectly. Furthermore, mono-tube design is able to decrease bounce caused by bump and bring sport performance into full play.

3. Radiation

The difference between mono-tube design and double-tube design is that mono-tube design contacts air directly so it is able to radiate properly. Please see the picture on your left-hand side. With large capacity, oil doesn’t deteriorate easily. With improvement for years, the performance of mono-tube design and the ability of remain damper force are pretty good. After using for a period, you should realize the difference between mono-tube design and double-tube design.

4. Inverted Type

Double-tube construction is unable to be designed as inverted type suspension. On the other hand, the rigidity of mono-tube inverted design is highly increased. As the result, the control, ground connection and the stability of driving are better than before. If double-tube is designed as inverted strut, oil and gas will be reversed and gas will enter inner tube and cannot work. Mono-tube inverted suspension is generally equipped on high-class product. Furthermore, mono-tube inverted suspension is the best choice for special purpose, such as drift, rally, and tracking racing.

Ride Height Adjustment of Rear Separated Coilover Instructions




The spring and the strut are separated on the rears of some certain vehicles. Please make adjustment in ride height and length of strut by carrying out the following steps:


  • Lower or raise the ride height by adjusting A.
  • After required ride height is reached, it’s essential to adjust the length of coilover by adjusting B to your desired position.
  • After required ride height is reached, put the tire on and move the vehicle around 5-10 m. Then please let C insert 1/3 part into the strut and leave 2/3 part outside the strut; tighten the spring perch lock (B).
  • The unusual noise and a breakdown will occur if failure in adjusting the length of coilover. Fasten 30mm strut into lower mount to keep safe.

Comparing TEIN, HKS, BILSTEN and K-SPORT

  K-SPORT TEIN COMPACT HKS BILSTEIN
TYPE STANDARD MONO FLEX BASIC COMPACT HIPERMAX SS9
PRICING USD
1,000 ~ 1,500
USD
1,850 ~ 2,050
USD
1,000 ~ 1,500
USD
2,000 ~ 2,200
USD
1,500 ~ 2,500
PILLOWBALL UPPER MOUNT YES YES NO YES NO
CAMBER ADJUSTABLE YES YES NO YES NO
DAMPING SETTING ADJUSTABLE YES YES NO YES NO
LEVEL OF DAMPING SETTING 36 16 NO 30 NO
PISTON MEASUREMENT ∮44 ~ 46 ∮32 ~ 40 ∮32 ~ 38 ∮40 ~ 46 ∮32 ~ 38
STRUT DESIGN mono-tube mono-tube double-tube mono-tube double-tube
HEIGHT OF STRUT YES YES NO YES NO
MATERIAL Aluminum Forged Iron Iron Iron Iron
TREATMENT Anodized Painted Painted Electroplated Painted / Electroplated
WARRANTY Replacement Maintenance Maintenance Maintenance Maintenance
SPRING RATE Selection freely Non-selection Non-selection Non-selection Non-selection
CUSTOM SPECIFICATION YES NO NO NO NO