Ext Shox Arma V4 Standard Coil Metric PSR shock

Legendary damping

Adding to an already legendary resume, EXT is proud to introduce the new Arma and Storia V4 Series. The V4 is specifically designed to raise the bar on what is possible in MTB damper performance technology. Don’t be fooled by the similar appearance to its V3 predecessor, for beneath the surface the V4 beautifully refines and improves what was already an industry game changer. Building off of their prestigious pedigree in motorsports racing, EXT has worked diligently to put out a damper that ensures its rightful place as innovative industry leaders in the highly competitive MTB marketplace.
The V4 not only retains and refines foundational aspects of the V3, such as its unique mid body damper characteristics, hydraulic bottom-out circuit and notable high speed control, while simultaneously addressing and integrating feedback from our riders. The V4 celebrates a position sensitive rebound hydraulic top out system, frequency dependent damping, an externally adjustable HBC and a steel DLC coated damper shaft. All of this and more coming in a stronger yet quieter package.

Features

• PSR (Position Sensitive Rebound): a new unique hydraulic top-out system that eliminates harsh top out and improves sensitivity.
• Riders can now adjust high and low speed compression with a common multi-tool, needing only 5 mm and 4 mm Allen keys.
• Frequency dependent damping Adjustable HBC: Once Developed by EXT for motorsport and later introduced in MTB applications, the new HBC system is now more powerful and starts in the last 20% of the stroke. This allows for a lower spring rate choice for maximum compliance, traction, and control.
• No risk of cavitation: high turbulent flow valves keep damping forces independent from viscosity and temperature changes to perfect pressure balance, eliminate aeration and cavitation, all with very low hysteresis to improve dynamic response.
• New coatings: improved durability thanks to a new proprietary DLC coating of the chrome-moly steel shaft, and an innovative proprietary DHC tube coating process, both assuring maximum wear resistance.
• Oil EV2S, a high viscosity index fluid, and phenomenal viscosity ratio.
• Spring thrust bearings ensure alignment, prevent spring rub and minimize spring noise.
• Reservoir with large volume bladder design, inflated to 55 psi only
• More silent.
• Spring NOT included

Technologies

Hydraulic bottom-out control
The HBC system is a position sensitive damper valve made of a secondary piston assembled below the main one, and an inner tube near the bottom of the damper. When the rider gets close to the end of the stroke, the secondary piston goes inside the inner tube, forcing the oil flow through a calibrated orifice that characterizes the end stroke ramp up. EXT’s HBC system engages just in the last 15% of the stroke and it’s also externally adjustable to match your weight, riding preferences and style.
This system makes the compression progressive, allowing lower spring-rate settings of the dampers and offering a balanced feeling and better traction. So, you can rely on a very plush feeling and a great support on the last millimeters of your bike’s rear travel. On the graph it is shown how HBC controls the last part of the stroke. The peak on the right side is the strength achieved by the shock when the HBC is full closed. The Hydraulic Bottom Out Control adjuster is located just above compression valve.

Lok 2.0 system
All of our MTB dampers feature the LOK 2.0 proprietary EXT technology, (aka pro-pedal switch), already well-known throughout the product line up. A 2-Way lock-out system improved to avoid any kind of bobbing while you pedal on every types of surface. Completely customizable, the LOK system has a blow-off valve that prevents any kind of damage if you forget the LOK lever before a downhill ride. It is made up of a completely independent valve system that controls the oil flow in a separate chamber and allows you to get the support needed for the best pedaling efficiency. In open mode, the LOK circuit is excluded, and when closed, the oil must flow through a preloaded shimmed valve increasing compression force. This shim-based design provides enough sensitivity and support to increase overall traction on rough terrain. Now, the LOK 2.0 system can also be custom tuned based on rider preferences.

Air spring 3
The core of the Aria is in the innovative dual positive air chambers and a large negative self-equalizing chamber. This system allows for extensive control over the shock’s air spring curve characteristics, giving you fine tune capabilities throughout the entire stroke. The dynamic nature of EXT’s twin positive air chambers virtually eliminates all negative aspects intrinsic to the volume spacer systems of competitors.