Index Electric Assist Systems for Trikes

Home Power Assist Basics Direct Drive Hubmotors Geared Hubmotors Mid Drive Motor Controllers & Displays Batteries & Chargers Pedelec Options HPV FS26 with MAC Power


Power Assist Made Easy

Its no secret that most of us who ride recumbent trikes have put our youthful days behind us. Recumbent trikes are a blast to ride and these days we have so many wonderful bike trails to ride on. True that the third wheel adds some drag and weight.

Climbing hills can be a bit of a chore, particularly in regions with rolling hills or mountains. Those who prefer a fast trike like the ICE VTX or Catrike 700 sometimes like to ride with a group of roadies but often find themselves at a bit of a speed disadvantage. Both problems are most easily solved with electric assist. Its not cheating; its merely a boost, and once you've dialed in the right system, there will be no regrets.

Choosing a system that fits your needs and budget can seem overwhelming when you look at all the product offerings and prices. Its a lot like choosing a first trike; you'll want the features that are the best match to your needs and liking at the best price.

Unlike a trike there are some variables that may be difficult to consider such as what kind of motor control you'll want or how to size the battery or even which class of drive will work best for your needs. As an engineer with over 30 years of experience designing electric powered machines I've taken considerable time and expense to research, purchase, and test various systems and my findings are published here for the trike community.

Defining your needs is an iterative process where you'll want to consider these key elements:

  • How much power (measured in watts) is needed?
  • Do you need part-time supplement such as only ascending hills or full-time power?
  • Would you prefer power for climbing hills or speed?
  • How much power will you consume on a ride?
  • How do you want to control the power output of the motor?
  • How much weight are you willing to add for a system?
  • What size and chemistry of battery do you need?
  • How much information do you want from the Computer Display?
  • How will you want the Computer Display mounted?
  • How will you want Motor Controls mounted?
  • How will the battery be mounted?
  • Who will be installing and maintaining the system?
  • How much are you prepared to spend on a system?

The process is iterative because you won't have all the answers at first, however as you learn about the 3 classes of motors, the control systems, and system components you'll begin to be able to make informed decisions to configure the system most suitable to your needs.

We'll begin with a summary of the 3 classes of motors. Click on the image for more detail.

1. Direct Drive Hubmotor

Simple low cost solution that lead the way for the E-Bike revolution.

  • Efficiency drops quickly at lower speeds
  • Efficiency is very good at higher speeds
  • 20" Rim is about the right size
  • Enables regeneration
  • Adds drag with power off
  • Lowest cost
  • Most reliable design

2. Geared Hubmotor

Adding a set of planetary gears significantly improved low speed efficiency. Adding a one-way clutch eliminated the cogging drag.

  • Takes less power to climb hills
  • Strong acceleration
  • Less top end speed
  • Lower weight
  • Some added cost
  • Plan on new gears every few years

3. Mid Drive Crankmotor

Crank motors rapidly emerged as they offer the ultimate in efficiency and weight. Dual clutch system allows proper motor freewheel.

  • Most efficient at low/high speeds
  • Easiest to install
  • Adds weight to the front
  • Not friendly to front derailleur
  • Pedelec challenged
  • Faster chain wear

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