See how to assemble the Manual interface (MHI) on a wheel with a 148mm modular axle hub.

Backward compatibility

This guide is compatible with legacy enviolo and NuVinci 148mm modular axle hubs.

Spline nut compatibility

There are 2 variants of the Manual hub interface (MHI) with different spline nuts (A) – 40T and 44T.

Their compatibility with Enviolo hubs depends on the year of the hub. Since 2025, we commmonized all hubs with 40T, but some older hubs have 44T splines:

2025

• Hubs with 40T – All hubs are commonized with 40T.
• Hubs with 44T – Discontinued.

2024 and earlier

• Hubs with 40T
  • 148mm modular axle – All modular hubs.
  • 135mm solid axle - Heavy Duty, Extreme, Extreme Gearbox, CA.
• Hubs with 44T
  • 135mm solid axle - Urban, City, Trekking, CO, SP, CA.

Step-by-step instructions

Video

 Tools

• Torque wrench
• 17mm long socket
• Marker pen (white)

Assembly instructions

1. Make sure the Manual hub interface you have has the correct amount of spline nut teeth for your hub:
   • The Urban, City, and Trekking hubs are compatible with 44T.
   • The Heavy Duty and Extreme hubs are compatible with 40T.
2. Determine the position of the wheel on the frame:
   • Typical orientation is forward, parallel to the chainstay, or via the seat stay cable routing.
   • Contrary to a 135mm solid axle assembly, the angle of the Manual hub interface in relation to the hub is not important when assembling the MHI on 148mm modular hubs.
   • Cables should not bend too much.
3. Make sure the Manual hub interface is rotated counterclockwise, to full overdrive position (H).
4. Remove the anti-shift retainer if one is installed on the hub.
   • The anti-shift retainer comes typically installed on new hubs.
   • If an anti-shift retainer is not installed, then make sure that the markings between the spline nut (C) and the shift driver (D) are aligned. If the marking are not aligned, you will need to reset the hub to full overdrive before proceeding.
5. Seat the hub interface fully onto the axle, onto the shift driver and spline nut.
   • Remember that the spline nut (C) and shift driver (D) markings must also be aligned, and the Manual hub interface must be in full overdrive (H).
6. Thread the right-hand 17mm nut, serrations facing outward, onto the axle.
   • Tighten it to 8-10Nm.

Next step

You should now have a rear wheel with a Manual Hub interface assembled. The next step would be to assemble the wheel into the bike frame. Proceed to this guide:

• How to assemble a Manual-equipped rear wheel on a 148mm modular axle frame