Custom Reduction Gears & Shafts for E-Motorcycle | DD Gear

Features & Benefits

• Optimized for single-speed electric drivetrains:
  E-Motorcycle Gears are designed around typical electric two-wheeler architectures—hub motors with integrated planetary reduction, or mid-drive motors with single-stage or two-stage spur/helical reduction—focusing on efficiency, torque density and NVH instead of multi-speed shifting.
• Small-module precision for high motor speeds:
  Electric motors often run at much higher speeds than ICE engines. Small-module gears with precisely controlled tooth geometry, runout and surface finish help maintain smooth meshing, low vibration and acceptable noise at high rpm.
• Support for hub-motor and mid-drive layouts:
  DD Gear can supply planetary gear sets (sun, planet, ring gears) for hub motors as well as spur/helical gears and shafts for centrally mounted motors and jackshafts, allowing you to standardize on one supplier across different E-motorcycle platforms.
• Material & heat-treatment options for high torque and outdoor exposure:
  Case-hardening steels, through-hardening alloys and nitriding steels are selected for contact fatigue strength, bending strength and toughness. Surface treatment and corrosion-control options can be applied to improve robustness against moisture, road salt and debris.
• Efficiency and NVH-oriented design & manufacturing:
  Well-controlled tooth micro-geometry, backlash and surface roughness support high mechanical efficiency and lower gear whine, which is particularly important because electric drivetrains are quieter and make gear noise more noticeable to the rider.
• Prototype-to-series production capability:
  DD Gear can provide early prototype sets for new motor/gearbox concepts, then stabilize processes and inspection plans for series production, supporting ramp-up and platform evolution over time.

Technical Specifications

Final data will be defined according to the customer’s drawing and sample.

Applications

E-Motorcycle Gears from DD Gear can be tailored to a variety of EV two-wheeler drivetrains, for example:

• Hub-motor planetary reduction
  Planetary gear sets integrated into rear or front wheel hubs of e-scooters or e-motorcycles to reduce motor speed and multiply torque while keeping the motor compact and limiting unsprung mass.
• Mid-drive single-speed reduction
  Spur or helical gear stages between a centrally mounted motor and an intermediate shaft, followed by chain or belt drive to the rear wheel, commonly used in higher-power e-motorcycles and e-mopeds.
• Two-stage reduction systems
  Compact two-stage gear reductions (spur/helical + chain or planetary + spur) to achieve higher overall gear ratios within tight packaging envelopes, especially when the motor operates at very high rpm.
• Auxiliary and wheel-side gear sets
  Gears and shafts in wheel-side reductions, parking locks, integrated freewheel mechanisms or ancillary drives where compactness and robustness are critical

Gear Manufacturing Process

Every e-motorcycle gear is produced under a controlled gear manufacturing route designed for precision and durability. A typical process flow is:

1. Forging or bar cutting of shaft blanks

2. Lathe machining of shaft diameters and reference surfaces

3. Hobbing or shaping of gear teeth

4. Drilling, milling, and other CNC machining operations

5. Heat treatment (such as carburizing, quenching, tempering, nitriding)

6. Shot blasting and stress relief as required

7. Finish machining and grinding of journals and critical surfaces

8. Gear grinding (profile or worm grinding) where accuracy demands it

9. Cleaning and rust prevention treatment

10. Final inspection and packaging for shipment

Precision Gear Customization Process

To support custom e-motorcycle gear projects, DD Gear follows a clear, eight-step customization process:

Step 1 – Requirement Collection
Customers provide design requirements, 2D drawings, 3D models, or physical samples, together with basic duty cycle information (torque, speed, life, installation).

Step 2 – Drawing Design & Optimization
Based on the provided drawings or samples, DD Gear prepares or optimizes detailed manufacturing drawings and shares them with the customer for confirmation.

Step 3 – Quotation
After the drawings and technical points are confirmed, we issue a precise quotation covering tooling, piece price, lead time, and quality requirements.

Step 4 – Tooling & Fixture Preparation
Once the price is confirmed, we arrange tooling and fixture production. Any tooling cost is agreed with the customer in advance and can be offset or refunded after mass orders, according to the commercial agreement.

Step 5 – First Sample Approval
After tooling and fixtures are ready, we manufacture the first sample batch—typically within about 30 days—and ship it to the customer for testing.The customer inspects and validates the samples in their gearbox or test bench and provides feedback on dimensions, performance, and any required adjustments.

Step 6 – Mass Production
When the sample is approved, we start mass production according to the agreed production plan and quality standards.

Step 7 – Finished Product Inspection
After production, we inspect hardness, dimensions, runout, tooth accuracy, and other critical characteristics to ensure full compliance with the drawing and standards.

Step 8 – Shipping Arrangement
Once inspection is passed and shipment is approved by the customer, we arrange booking, packaging, and delivery to the specified destination.

Quality Assurance & Inspection

DD Gear applies the same quality philosophy to e-motorcycle gear and all precision gears:

• Quality management systems based on ISO 9001 and IATF 16949

• Process control from incoming material to final inspection, including:

  • Material certification and chemical composition checks

  • Hardness and case depth verification after heat treatment

  • Gear measurement for profile, lead, pitch, and runout

  • Surface roughness testing on gear flanks and journals

  • Dimensional inspection with calibrated gauges and CMMs

• Traceability for each batch with inspection records and reports

• Optional documentation such as PPAP/FAIR packs on request

Packaging

Usage & Installation Notes

• Ensure shaft alignment, bearing support and housing stiffness follow the design; misalignment can quickly increase noise and wear, especially at high rpm.
• Use the specified lubricant type, viscosity and fill level; electric two-wheelers often rely on sealed gearcases with limited oil volume, so cleanliness and correct filling are critical.
• Avoid mixing gears from different sets unless they are explicitly designed to be interchangeable; planetary sets in particular depend on matched geometry.
• Monitor noise, vibration and temperature changes during development and service; abnormal trends should trigger inspection of tooth contact, lubrication condition and bearing health.
• Protect gears from corrosion and contamination during storage, shipping and vehicle assembly, especially where they share space with electric motor components and seals.

Company Strength – DD Gear

• Specialized in small module, high-precision gears and shafts for EVs, humanoid robots, AGVs, and intelligent automation.

• Integrated manufacturing from forging and machining to heat treatment and gear grinding.

• Quality systems aligned with automotive standards, with experience supporting OEM and Tier 1 projects.

• Engineering support covering concept feasibility, DFM reviews, and failure analysis feedback.

• Global export capability with experience serving customers in multiple countries.

Q1: What information do you need to quote E-Motorcycle Gears?
We typically need: drivetrain layout (hub motor / mid-drive / other), 2D drawings and preferably 3D models, gear type (spur/helical/planetary components/gear shafts), module and tooth data, materials and heat-treatment requirements, motor speed and torque, wheel size and target vehicle speed, duty cycle, lubrication concept and annual volume.

Q2: Do most electric motorcycles need multi-speed gearboxes?
Most small and medium electric two-wheelers use single-speed reductions, because electric motors deliver a broad torque range and can be controlled electronically. A small number of high-performance projects explore multi-speed transmissions, but the majority of applications focus on optimizing a single gear ratio for efficiency, acceleration and top speed.

Q3: Should we use spur, helical or planetary gears in our design?
Spur gears are simple and efficient and work well for many mid-drive reductions. Helical gears offer smoother, quieter operation and higher load capacity but introduce axial thrust. Planetary gears are well suited to compact hub-motor reductions and high overall ratios in limited space. The right choice depends on your packaging, NVH, cost and manufacturing strategy.

Q4: Can DD Gear supply complete hub motors or gearboxes?
DD Gear acts as a component supplier. We manufacture gears, gear shafts and related components according to your drawings. Complete hub motors, gearboxes and fully assembled vehicles are designed and assembled by the E-motorcycle OEM or system integrator.

Q5: How can we address gear noise in quiet electric drivetrains?
Gear noise can be reduced by combining appropriate tooth geometry, accuracy levels, surface finish, lubrication and housing stiffness. DD Gear can support with manufacturability-oriented feedback on tooth modifications and tolerance schemes, but final NVH performance must be validated in the full drivetrain and vehicle.