Erion
Erion
Magnetic chaindamper for mountain bikes
Shipping & Returns
- Shipping only within Switzerland
- Shipping Cost: CHF 7.00
- Delivery within 7 days
- Easy returns
Which angle do I need?
You only need your phone and one minute.
1. Shift into the hardest gear and apply pressure to the pedal to tension the chain.
2. Hold your phone flat above the chainstay, around one third of the way from the chainring to the rear axle, and take a photo from above.
3. Compare your photo with the two examples. The green line shows the chainstay and the blue line shows the chain. The angle where they meet is what matters.
6°
12°
To 9° choose 6°, over 9° choose 12°.
Unsure? Send us a photo of your chainstay to info@araxy.ch, we'll tell you which angle you need!
Description
The Erion is a magnetic chain damper for mountain bikes. Inspired by the Ancient Greek word eirene, meaning peace, harmony and calm, the Erion brings exactly that to your ride. It keeps your chain securely in position whenever it is not under tension and releases it instantly as soon as you start pedalling. This creates a quieter and more controlled ride without friction, resistance or an unnatural feeling at the pedals.
The system consists of two components: a front and a rear unit. The front unit provides a single contact point, while the rear unit features two angled contact surfaces. These follow the chainline in the smaller cassette cogs, the gears you typically use when riding downhill.
This purpose built design engages the chain only where it matters, providing maximum damping and chain control on descents. In the higher climbing gears, the Erion remains outside the chainline, allowing you to pedal naturally and efficiently.
The Erion is designed to fit almost any modern mountain bike. Height adjustable and trimmable adapters allow for precise adjustment to your frame.
Since most chainstays do not run parallel to the chainline, the rear unit is available in two offset angles: 6° and 12°. This allows the housing to follow the angle of your chainstay while keeping the contact surface precisely aligned with the chainline.
The contact surfaces are fully replaceable wear parts. When replacement is needed, they can be changed quickly and easily without replacing the entire Erion.
Designed and tested in Switzerland.
Features
- Magnetic chain control — Holds the chain securely when it is not under tension, reducing chain slap and unwanted movement on rough descents. It releases instantly when you pedal, so the chain can move freely without friction or an unnatural pedal feel.
- Descent-focused performance — The two-piece system guides the chain precisely in the lower gears typically used downhill, while staying clear in higher climbing gears for unrestricted pedalling.
- Fits most modern MTBs— Secured with four cable ties, the Erion adapts to a wide range of chainstay shapes. Cut-to-size height adjusters and adjustable rear positioning allow it to be tailored precisely to your frame.
- Three offset angles — Choose between 0°, 6°, and 12° offsets to match your chainstay angle while keeping the contact patch aligned with the chain path.
- Fine-tunable setup — Adjust the rear unit’s height, distance, and angle to achieve reliable chain contact and optimal performance.
- Replaceable contact patches — Worn contact surfaces can be replaced quickly without changing the complete housing, keeping the Erion durable and easy to maintain.
FAQ
Is the Erion compatible with my bike?
The Erion is designed to fit most modern mountain bikes, provided there is sufficient and relatively consistent clearance between the chain and the chainstay.
For a reliable fit, your bike must meet these three requirements:
- There must be at least 15 mm of clearance between the chain and chainstay when the chain is under full tension.
- The distance between the chain and chainstay must remain reasonably consistent along the intended mounting area.
- The chainstay needs to be below the chain.
If the chain sits far away from the chainstay near the chainring but runs very close to it near the cassette, the Erion may not achieve the correct fit. This can apply to certain high-pivot bikes with idler pulleys, such as the Commencal Supreme DH V5, as well as some older Santa Cruz VPP suspension layouts. High-pivot designs use an idler pulley to route the chain around the suspension system, which can create a chain path that is unsuitable for an Erion installation.
When in doubt, use the installation guide to check your frame before ordering.
How do I install the Erion?
Installing the Erion is quick and straightforward. Everything required for mounting is included in the box—you only need an Allen key and cutters to trim the ends of the cable ties.
- Cut the height adjusters to the required length for your frame.
- Set the rear unit’s height adjusters to the correct position.
- Secure the Erion to the chainstay using the supplied cable ties.
- Trim the excess cable-tie ends for a clean finish.
For a precise setup and the best possible performance, follow the detailed step-by-step instructions in our Support section.
How do I choose the angle?
The Erion is available in three offset angles: 0°, 6°, and 12°. Selecting the right option ensures that the housing follows the chainstay while the contact patch remains aligned with the chain path.
First, determine the intended mounting position on your chainstay using the installation guide. Then view the bike from above and check the angle between the chain and the chainstay at that exact location. Choose the Erion angle that most closely matches this offset.
The examples below help you estimate the offset angle you need. The green line represents the chainstay, while the blue line represents the chain line. What matters is the angle created where the two lines intersect. Choose the offset angle that matches it as closely as possible.
This gives you the cleanest fit, reliable chain contact, and the best damping performance on the trail.
Chainstay and chain line intersect,
the angle is 6°.
Chainstay and chainline are angled, the angle is 12°.
How do I maintain my Erion?
The Erion is built to be as maintenance-free as possible. Treat it like any other durable component on your bike: ride it in wet, dusty, and demanding conditions, clean the bike normally, and keep an occasional eye on the replaceable covers.
The system has been developed for harsh riding conditions and can handle regular washing. The only part that requires monitoring is the contact cover, as it is intentionally designed to wear instead of the main housing.
When should I replace the cover?
Chain contact gradually wears the replaceable covers over time—this is normal and protects the Erion housing underneath.
Inspect the covers regularly and replace them once the thinnest area measures less than 0.3 mm. Replacing the cover at this point prevents it from breaking and keeps the main housing protected for long-term use.
The replacement process is simple: remove the retaining screw, replace the worn cover, reinstall the screw, and your Erion is ready to ride again.
Chainless feel with a chain
The Erion holds your chain in place and damps disruptive chain movement. Less vibration from the drivetrain reaches your pedals, so your bike rides more calmly, almost as if it had no chain. The moment you push on the pedals, your drivetrain is fully there.
Together with Downamics, a data acquisition specialist established in the World Cup, we measured it: between 30 and 100 Hz, exactly where the restless feeling in your feet comes from, significantly less vibration reaches the crank with the Erion than with a standard chain setup. Over long stretches it matches the chainless setup, and in places it is even lower.
On the trail, that means calmer feet without giving up your chain. The chainless feel stays. So does your drivetrain.
