EXT Ferro USD 36 Fork

Description

The EXT Ferro is a real breakthrough in the dirt e-bike world. It’s the very first suspension designed and engineered from the ground up for the needs of our light electric dirt bikes. This inverted style fork brings our Talaria, Sur Ron and others like the Drill One to new heights of performance.

In a word, this is by far the very best performing fork on the market. It has in-class lateral stiffness, offers the best sensitivity on small bumps all the while allowing to seperately tune your end of stroke with the dedicated secondary air chamber.

Chassis

Entirely designed and manufactured in Italy, the Ferro is an upside down moto style fork with a 7075 aluminium body and 36mm hard chromed steel stanchions with 200mm of travel.

The heat-treated stanchions feature a Superfinish surface treatment, allowing the most sensitive damping while offering an unrivaled stiffness, putting many full size forks to shame.

EXT uses CGB (Continuously Guided Bushing) and Dedicated Mobile Sliding DU guiding system to increase stiffness. Radial rigidity at the wheel is taken care of by using a Twin hexagonal floating axle.

As it was designed with our e-motos in mind, the Ferro USD 36 is fully compatible with the Light Bee and Talaria sting’s factory fenders.

Air Spring System

The secret behind the Ferro’s performance is the patented HS3 technology. The EXT hybrid air spring system uses two positive air chambers:

• the main chamber sets the SAG and the first half of the stroke,
• the secondary chamber defines the damping curve and allows to ramp up support without affecting sensitivity.

This twin positive air system, along with the high volume self-equalizing negative air chamber, provides unparalleled mid-stroke support while simultaneously offering amazing sensitivity and bottom-out protection.

Hydraulic Cartridge

The high flow hydraulic cartridge offers adjustments in 3 ways: high & low speed compression and rebound adjustments.

The EXT bespoke cartridge features a high dynamic response valve (HDRV), incorporating two distinct shim stacks for optimum mid-speed and high-speed behaviour.

What’s included

• EXT Ferro USD 36 with upper and lower crown
• EXT high pressure pump
• bump stops
• MTO bespoke hose guide

Technical details

Install & Settings

For install, torque values and maintenance, please refer to EXT user manual or the quick manual.

EXT recommends 65 PSI in the + chamber and 100 PSI in the ++ as a baseline. Quentin weights about 50kg (110lbs) and found out these values to be largely too soft for correct support and feeling.

After careful testing and extended riding, both in enduro and on the track, we recommend 100+ / 200++ as a baseline for an average weight rider. You’ll want to start with both rebound, HSC and LSC tuned at the middle and adjust from there based on your own feeling on the terrain.

The + chamber defines the main behaviour and the SAG. Start by adjusting the SAG: it needs to be in the range of 25 to 40mm and then adjust based on your liking and the feeling of sensitivity and terrain feedback you need.

Once settled, increase the ++ to get the support level you need. The higher the pressure in the ++, the more support you get in the second half of the stroke and the steepest the damping curve.

Once you’ve more or less found your working pressures, start adjusting the rebound, HSC and LSC to fully match your needs.

NB: Please note that the pressure in the ++ chamber is to be higher than in the + chamber at all times and that the max pressure for both chambers is 300 PSI.