FENRIR Motorcycle Bar End Mirror Adapter 801-0399 — Aluminum CNC, Anodized Finish for Internal-Thread Handlebars

This adapter converts handlebars with a factory internal thread into a secure mounting point for FENRIR bar-end mirrors. Machined from aluminum alloy and finished with an anodized surface, the 801-0399 is engineered to match the fit and finish of FENRIR mirrors and to simplify installation with a straight bolt-on design.

Will this adapter fit my motorcycle’s handlebar?

If your handlebar has a factory threaded insert inside the open end, the FENRIR 801-0399 will bolt in without modification. It is designed specifically for handlebars that accept internal threaded bar end components.

• Fits handlebars with original internal threaded ends.
• Direct bolt-on installation—no cutting or rethreading required.
• Not compatible with handlebars lacking internal threads or with external-threaded bar ends.

Can I use this adapter with other brands of mirrors?

No — the adapter is purpose-built to interface with FENRIR bar-end mirrors only. The internal geometry, thread pitch and locking method are matched to FENRIR mirror fittings for a correct, vibration-resistant connection.

• Exclusive compatibility: made for FENRIR bar-end mirrors.
• Avoids improper fits that can cause looseness or damage.
• Ensures mirror alignment and secure clamping designed by the brand.

How is the adapter made and how durable is it?

The 801-0399 is CNC-machined from aluminum alloy for consistent tolerances and strength. An anodized finish protects the surface against corrosion and road wear while giving a refined look that complements FENRIR mirrors.

• CNC precision machining for repeatable fit and finish.
• Aluminum alloy construction for strength with low weight.
• Anodized coating improves scratch and corrosion resistance.

What should I expect during installation?

Installation is straightforward when your handlebar has the required internal thread: slide the adapter into the bar end and tighten the supplied fastener to secure it. Standard hand tools are usually sufficient; follow torque recommendations from FENRIR to avoid over-tightening.

• Straightforward bolt-on process—no special tools required.
• Check alignment before final tightening to ensure correct mirror positioning.
• Consult FENRIR instructions for torque and mirror mounting steps.

Who is this for: The FENRIR 801-0399 adapter is aimed at riders who already own or plan to install FENRIR bar-end mirrors and need a compatible mounting solution for handlebars with internal threads. It’s ideal for motorcyclists seeking a factory-style fit, lightweight durability, and a coordinated look with FENRIR mirror assemblies. If your motorcycle uses different bar-end hardware or mirrors from another brand, this adapter will not be suitable.