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Tein coilover kit - FLEX Z

High-end Top Quality shock absorber at an amazingly low price


Starting with the FLEX Z line, we will bring a new affordably priced version of our STREET FLEX coilovers. How affordable? MSRP will start from $1000

Features-wise, not much is different from the current STREET FLEX. It will still include full-length ride height adjustment for separate spring preload and height settings, upper mounts (camber adjustable for most MacPherson struts), 16-way damping force adjustment using our ADVANCE NEEDLE technology which provides a much wider range of damping force adjustment per click (~ 200% increase in damping force adjustment range over our previous needle design), EDFC series compatibility, and our proprietary coatings (ZT coated damper bodies, and our 2-layer/1-bake powdercoating for lower brackets and upper mounts). We were able to bring cost down on the new FLEX Z dampers by making them fully sealed units (non-rebuildable).

The biggest benefit to a fully sealed non-rebuildable damper, other than the extremely affordable price, is that the customer will have a maintenance free damper (we still recommend to periodically inspect external components such as seat locks and spring seats, dust boots, and bump stops). Instead of rebuilding their damper, or if they have a blown damper several years down the line, they can purchase a replacement single damper. This translates into less downtime for our customer, who most likely needs to get their car back on the road.


  • Twin tube system for comfortable street ride
  • Full length adjustment design for ride height adjustment with minimal effect on ride quality
  • 16-way damper settings to change ride from comfortable to sporty (expandable to 32 and 64-way with EDFC)
  • Compatible with Tein's EDFC for in-cabin damper adjustment.
  • High quality damper oil and springs used
  • Extremely rigid bracket and shell casing
  • Affordable and customizable servicing to bring coilovers back to life.
  • Upper mounts included for easy installation.
  • Camber adjustable tops available for certain models.

Tein coilover kit - FLEX A

Comfortable drive in ALL seats with new hydraulic bump stopper


That’s not to say that we’re not proud of our overhaul/revalve service. In fact, we will continue to provide that for older coilover models and for some upcoming, such as the FLEX A.

The FLEX A coilovers will carry the same features as FLEX Z but will be rebuildable, much like the current line of STREET FLEX. We will also include a newly developed feature, our Hydraulic Bump Stop (H.B.S.). Technically it is not a new feature. Instead it is a much more affordable and effective version of the Hydraulic Bump Stop we use on our GROUP N dampers used in rally racing.

How does our HYDRAULIC BUMP STOP work?

As the damper reaches/nears full compression, there is a spring that the piston makes contact with. This helps to build up pressure closer to the base valve. As pressure continues to build around the base valve, a secondary spring will compress, which allows a cup shaped washer to seal most of the orifices around the base valve.  This effectively restricts damper fluid flow, increasing this pressure and slowing down the piston’s speed. Finally, as the damper approaches full compression, a third spring will compress allowing a needle washer to open and allow damper fluid to pass through this single orifice.  In all, the way our HYDRAULIC BUMP STOP works is by gradually increasing pressure during compression. While mainly based on piston speed (high-speed compression), the unit will work even as the damper nears full compression.

HBS Vehicle Image

This means that the damper will not fully bottom out. The effect on ride quality is that it will not be as harsh during rebound, much like would be the case with a longer polyurethane bump stop. Why is that? A polyurethane bump stop is compressible. However, it acts as a much stiffer spring, which the damper isn’t necessarily valved properly to control. This means that rebound force is much greater, and that can also translate into uncomfortable oscillation (where the vehicle feels very floaty). With our H.B.S. the rebound rate is not affected, and the vehicle can return to it’s 1g (vehicle weight on the ground) ride height in a smoother fashion.

HBS Vehicle Image


If you’ve ever watched videos of off-road race prepared trucks with very long stroke suspension, which use another form of hydraulic bump stop (typically mounted externally from the damper), watch what happens after a huge jump. The vehicle lands back down, suspension squatted nearly all the way down. However, when the suspension rebounds and the vehicle returns to it’s 1g ride height, it just settles. No crazy up and down movement. In other words, there is no wasted vehicle body movement. The driver can continue driving full throttle after a jump. Pretty impressive!

That may be a bit of an exaggeration of what our H.B.S. does for a street car (unless you compare it to our aforementioned Group N dampers, which go on production vehicles), however it is the same effect, just in a smaller package and for a shorter damper stroke.

Our HYDRAULIC BUMP STOP works extremely well on suspensions with longer stroke, such as luxury sedans or mini vans. While still effective and beneficial in applications with shorter damper stroke, it isn’t as noticeable in feel.

The new FLEX A coilovers will start at $1350 for a complete set!


  • New Hydraulic Bump Stopper (H.B.S.) for Comfortable Ride in ALL Seats!
  • Twin-Tube System for Comfortable Ride on Streets!
  • Full-Length System for Ride Height Adjustment w/ Minimal Change in Ride!
  • Damping Force Adjustable to Change Ride to Desired Settings!
  • Compatible with EDFC Series to enable In-Car Damping Force Adjustment!
  • Upper Mounts Included for Easy Installation!
  • Highly Durable & Reliable!
  • Thoroughgoing Rust-Proofing!
  • Highly-Rigid Bracket & Shell Case!
  • Smooth Ride Height Adjustment
  • No-Sag Springs!
  • High-Spec Damper Oil!
  • Available for Overhaul & Revalving!


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FLEX A & FLEX Z More Affordable

TEIN Senior Managing Director Yoshiro Fujimoto talked about the aim of the new product launch, "Our goal as we release the new products for 2015 is to increase the choices of our customers: products that are affordable due to cost reduction. These are directed towards customers who want to buy cheaper products. We will also be releasing products that adopts new technology for customers who want to improve their riding experience. We have designed the products based on both aspects."

The FLEX Z is a low price product which is the first of the company to utilize an airtight damper. On the other hand, the FLEX A is a product that improves riding comfort. It is equipped with the new mechanism known as the Hydraulic Bump Stopper (H.B.S). These are the two products scheduled for release into the market.

With regards to the current state of the after parts market, Fujimoto said, "The consumption tax has gone up as expected and the first quarter was a struggle. However, it has improved since that time and it somehow seems to head towards a positive trend. The market trend is also on the move starting with the release of the new Odyssey luxury minivan, the sports-type 86 and BRZ. We want to attack 2015 with our two new products."

In addition, with regards to future prospects including overseas expansion, Fujimoto said, "We hope to further expand the width of our products since we are going to promptly start operations next year in China. We are also thinking of expanding our products to kei car users, premium replacement class products intended for users who want to improve the riding comfort a bit more through a perfect form, or a heavy duty shock absorber that is geared towards bad road markets where shock absorbers are considered as a consumable and are normally replaced."

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