Why doesn’t your 15mm Boost wheel fit your new RockShox BoXXer? Most modern trail bikes, enduro bikes and e-bikes use a 15×110 Boost front hub. The RockShox BoXXer uses a larger 20mm downhill axle system. The hub width may be 110mm, but the axle diameter and fork interface are different. That is why your 15×110 Boost wheel cannot simply be installed in your BoXXer.
The Freakynuts® RockShox BoXXer 15mm Adapter solves exactly that problem. It allows you to use a compatible 15×110 Boost front wheel in your RockShox BoXXer without buying another complete front wheel. One wheel. More bikes. Less hassle.

Use Your Existing 15×110 Boost Wheel

A second downhill front wheel quickly becomes expensive. You need another rim, hub, brake rotor, tyre, tubeless setup and possibly another tyre insert. If you already own a wheel that you like, why build another one just because your BoXXer uses a 20mm axle?
The Freakynuts® adapter creates the correct interface between your 15×110 Boost wheel and your RockShox BoXXer. No permanent modification to your fork. No permanent modification to your wheel. Just a purpose-built adapter system.

CNC Machined in Germany

Every Freakynuts® adapter is CNC machined in Germany from premium 7075 aluminium. 7075 is used because the front axle area of a downhill bike has to deal with serious braking forces, impacts and repeated loads. The material offers high strength, excellent stiffness and very good fatigue resistance without unnecessary weight.
Every component is manufactured to precise tolerances so the wheel sits where it belongs.

Precision Instead of a Loose Sleeve

A downhill adapter should do more than simply reduce a hole from 20mm to 15mm. The wheel must be positioned accurately inside the fork and supported correctly by the complete axle system.
That is why Freakynuts® adapters are designed as a complete mechanical solution. The result is a precise fit, secure axle support and consistent wheel positioning.

No Saw Cuts. No Fork Modifications.

We do not believe an expensive downhill fork should be drilled, cut or permanently modified just to use another front wheel. The Freakynuts® system is designed to work without irreversible modifications to your RockShox BoXXer.
Your wheel remains a normal compatible 15×110 Boost wheel, so you can still use it in another Boost fork when required.

Basic, Pro or Premium

The Basic Adapter is ideal if you already have a suitable 158mm long 15mm thru axle.
The Pro Kit combines the precision adapters with our Solid HellPin 7075 thru axle for a complete Freakynuts® setup.
The Premium Kit is our flagship solution, combining the adapter and axle concept into a more integrated system with fewer separate parts.
Choose the version that fits your bike and riding style.

Built for Downhill and Freeride

The RockShox BoXXer is made for downhill racing, bike parks and aggressive gravity riding. That is exactly the environment the Freakynuts® system was developed for.
Use the front wheel you already know. Use the tyre setup you already trust. Ride your BoXXer without building another complete wheel.
Freakynuts® RockShox BoXXer 15mm Adapter. Ride your 15×110 Boost wheels everywhere.