Which (Cube) Bikes Are Mid-Drive Compatible? Don’t Convert Until You Read This

Essential Hardware Checklist

• CNC High-Precision Reducer Support Bushings Mandatory for all Press-Fit (41mm bore) shells — BB86 and BB92 — to bridge the 7.5mm mechanical gap between the smooth bore and the motor axle.
• 1mm / 2mm Precision Spacer Kit Mandatory for all 100mm axle installs to ensure perfect motor centering and prevent axle bottoming out.
• Protective Interface Pads Required for all carbon (C:62 / C:68X) frames to distribute clamping loads and prevent resin fractures.
• Precision Torque Wrench Non-negotiable for carbon builds to maintain the strict 35–40Nm lockring limit.

Critical Operational Rules

• The 3-Second Calibration Rule You must keep all weight off the pedals for at least 3 seconds after powering on the T24 display to allow the torque sensor to establish a zero-load baseline.
• Manual Shifting (DM02) Since the DM02 lacks an integrated shift sensor, the rider must consciously pause pedaling during gear changes to protect the drivetrain.
• Suspension Clearance Test For all full-suspension models — Stereo 120 HPA (2018+), Stereo 140, 150, 160, 180, ONE22, ONE44, ONE55, ONE77 — you must deflate the rear shock and compress the linkage fully to ensure it does not strike the motor housing at any point in the travel arc.
• Year-Specific Verification (Stereo 120 HPA) The Stereo 120 HPA uses BSA 73mm threaded before 2018 and BB92 press-fit from 2018 onwards. You must physically inspect the shell or verify your model year before ordering any hardware.

Category 1: Mountain Bikes — Hardtail

Cube’s hardtail mountain bike lineup spans aluminum HPA and C:68X carbon construction. The aluminum platforms are among the most straightforward conversion candidates in this guide. The carbon Elite C:68X and Reaction C:62 require careful attention.

Category 2: Mountain Bikes — Full Suspension

Cube’s full-suspension lineup spans aluminum and carbon variants across two bottom bracket standards. All full-suspension models carry a mandatory suspension clearance test requirement — no exceptions, no shortcuts.

Category 3: Road Bikes

Cube’s road lineup requires precise attention because aluminum and carbon variants of the same model name use completely different bottom bracket standards. Verify your exact variant before ordering anything.

Category 4: Gravel Bikes

Category 5: Trekking Bikes

Category 6: City and Urban Bikes

Welcome to the mechanical core of your Cube bicycle. The bottom bracket is the single most critical factor in determining whether your Toseven conversion succeeds or fails. Cube manufactures some of the most precisely engineered bicycles in the European market — but to achieve this level of refinement, they deploy a diverse set of bottom bracket standards across their lineup. You cannot buy a Toseven motor, slide it into any Cube frame, and expect it to work. Understanding your frame’s mechanical interface is non-negotiable.

1 What is a Bottom Bracket?

The bottom bracket (BB) is the hollow, cylindrical tube at the very lowest point of your bicycle frame. It is the structural junction where the downtube, seat tube, and chainstays all converge. On a standard Cube bicycle, this tube houses bearings that allow your crankset to spin. In a Toseven mid-drive conversion, the entire original crankset — pedal arms, spindle, and bearings — is removed completely. The Toseven DM01 or DM02 motor axle slides directly through this empty tube, and a large steel lockring is threaded onto the axle on the non-drive side, clamping the motor body tightly against the frame. The bottom bracket is no longer a bearing housing. It becomes the primary structural anchor for a motor generating up to 160Nm of rotational force. If the motor does not fit this tube correctly, the installation will fail catastrophically.

2 Threaded vs. Press-Fit: The Mechanical Reality

The Threaded Bottom Bracket (BSA)

• The Design The inside of the frame’s BB shell features spiral threads machined directly into the metal.
• The Fit The internal diameter is approximately 33.6mm to 33.9mm.
• The Toseven Advantage The Toseven motor axle is manufactured to exactly 33.5mm — natively designed to slide through a BSA shell with virtually zero radial play.
• Clamping Load The clamping hardware locks directly against the flat threaded faces of the shell. This is the safest and most mechanically sound conversion interface possible.

The Press-Fit Bottom Bracket (BB86 / BB92)

• The Design A Press-Fit shell has no threads. The inside is a perfectly smooth bore.
• The Fit Cube’s standard press-fit shells have an internal diameter of exactly 41mm.
• The Engineering Problem If you slide a 33.5mm Toseven motor axle into a 41mm press-fit bore, the motor floats loosely inside the frame. The immense twisting force of the motor would cause it to violently pivot inside the bore, permanently destroying the shell.
• The Solution To safely bridge this 7.5mm gap safely, you must use CNC High-Precision Reducer Support Bushings — machined metal sleeves that press tightly into the 41mm bore, stepping it down to exactly 33.5mm.
• Axle Length Requirements BB86 shells are 86.5mm wide. BB92 shells are 92mm wide. A standard 68mm or 73mm motor axle disappears entirely inside either shell with no thread protrusion for the lockring. You must use the 100mm axle motor variant for all press-fit Cube frames.

3 Cube Bottom Bracket Standards — Critical Breakdown

Cube does not use a single press-fit or threaded shell across their lineup. The width of the shell determines exactly which Toseven motor variant you must purchase.

4 The Precision Centering Rule (Mandatory Enforcement)

When installing a 100mm Toseven axle into an 86.5mm (BB86) or 92mm (BB92) Cube frame, you will have leftover exposed axle space that must be filled precisely. You must adhere strictly to the Precision Centering Rule: the motor must be perfectly centered in the frame, and the 1mm / 2mm Precision Spacer Kit must be used to fill any mechanical gaps on the axle. This is non-negotiable for three reasons:

• Preventing Axle Bottoming Out Without spacers, the lockring runs out of threads and hits the unthreaded shoulder of the axle before it ever contacts the frame face. The nut feels tight at the wrench but the motor is mechanically loose. Under motor torque, the loose motor pivots and tears the shell apart.
• Preventing Uneven Load Distribution On carbon Cube frames, asymmetrical clamping pressure from a non-centered motor fractures the carbon fiber resin matrix even at reduced torque settings.
• Preventing Chainline Bias A motor shifted too far toward the drive side pushes the chainring outboard, causing chain drops in climbing gears. Too far toward the non-drive side, the motor casing contacts the frame tubes and the chainline shifts inboard. Correct spacer distribution centers the motor and establishes a clean, drop-free chainline.

5 The Carbon Frame Protocol

Cube’s C:62 and C:68X carbon fiber is engineered to resist tensile pulling forces generated by pedaling. It is not engineered to withstand localized compressive crushing forces. The DM01 generates 160Nm of torque. The metal mounting plate acts as a lever against the frame. This lever transfers the motor’s rotational force as a crushing compressive load against the carbon walls of the BB shell. The result is carbon fiber delamination, resin matrix fracture, and permanent frame destruction. There are no exceptions and no torque settings at which the DM01 becomes safe on a carbon Cube frame. The DM02’s 90Nm output, combined with the strict 35 to 40Nm lockring limit and protective interface pads, distributes the compressive load within the structural limits of Cube’s carbon layup.

As a professional drivetrain specialist, these are the exact failures I see on Cube conversions repeatedly. Do not let your build fall victim to them.

• Ordering the Wrong Axle Length for a Press-Fit Shell The Elite C:68X, Stereo 120 HPA (2018+), ONE22 HPA, Nuroad aluminum, and every carbon road and gravel platform use shells that are 86.5mm to 92mm wide. A 73mm axle disappears inside the frame entirely — there is zero thread exposure for the lockring. Measure your shell width face-to-face with a caliper before ordering anything.
• Assuming the Nuroad Aluminum Is BSA Threaded Every other aluminum Cube platform in this guide uses BSA threaded. The Nuroad aluminum is the single exception — it uses a press-fit BB86 despite being an aluminum frame. This is the most consequential ordering mistake in the Cube lineup. Remove the existing bottom bracket and physically inspect the shell before ordering. A smooth bore means press-fit. Visible threads mean BSA.
• Assuming the Stereo 120 HPA Is Always BSA Threaded The Stereo 120 HPA used a BSA 73mm threaded shell before 2018 and switched to BB92 press-fit from 2018 onwards. These two frames require completely different hardware. You must verify your model year and physically inspect the shell before ordering.
• Installing the DM01 on Any Carbon Cube Frame It does not matter what the frame costs, what model year it is, or what trim level it carries. The DM01 is strictly prohibited on every C:62 and C:68X Cube frame without exception. The frame will be permanently destroyed. There is no recovery and no repair for crushed carbon fiber at the BB shell.
• Using Cheap Third-Party Bushings on Press-Fit Frames Plastic, nylon, or 3D-printed press-in adapters appear to fit and feel stable at installation. Under 90Nm of DM02 torque on the first real climb, they crush instantly. The steel motor axle then contacts the bare carbon or aluminum bore and gouges the shell permanently beyond repair. You must use official CNC-machined metal High-Precision Reducer Support Bushings on every press-fit Cube frame in this guide.
• Skipping the Spacer Kit on 100mm Axle Builds Even with correct bushings and the correct 100mm axle, discarding the 1mm / 2mm Precision Spacer Kit will result in axle bottoming out. The lockring feels tight at the wrench but the motor is mechanically loose. Under motor torque, the loose motor pivots and tears the CNC bushings clean out of the shell in a single hard acceleration event.
• Skipping the Suspension Clearance Test on Full-Suspension Platforms Cube’s lower suspension linkage sweeps directly through the motor housing space as the shock compresses. Skipping the clearance test means the first hard trail impact drives the linkage into the motor housing at speed. The result is a shattered motor casing or torn suspension pivot — both failures that are serious crash risks.
• Ignoring Internal Cable Routing on Cube Frames Cube’s integrated internal cable routing exits near the BB shell on virtually all modern platforms. Clamping the motor body against cables trapped between the motor and the frame causes brake failure, jammed shifting, and false torque sensor readings that generate erratic uncontrollable power delivery. Always route cables around the motor block with protective conduit before tightening any hardware.
• Attempting to Convert the TWO15 or Either Aerium Platform The TWO15 uses a 107mm DH-specific press-fit shell for which no Toseven axle variant exists. The Aerium platforms use extreme aerodynamic tube profiles that physically prevent correct motor positioning. Do not attempt electrification on any of these three platforms under any circumstances.