Electric Assist Trike
From Glen Aldridge, proprietor of Mid-Island Trike Adventures in Parksville, British Columbia Canada, comes this very informative article about electric assist solutions for recumbent trike touring. Click HERE to visit Glen’s company website. Below is a photo of Glen on the road:
ELECTRIC ASSIST SOLUTIONS FOR RECUMBENT TADPOLE TRICYCLES
by Glen Aldridge
ELECTRIC TRIKES – Are you considering an Electric Assist for your trike? You have many options & the information can be daunting. Watts? Amps? Sine Wave? Geared? Brushless? etc. etc. Here is all you need to know to make an informed choice.
For Trikes you have 2 main choices for converting to an Electric Assist. A Motor in the Rear Wheel or a Motor that drives your Chain.
To control the power going ultimately to your back wheel you need a control device. This can be a ‘hard control’ throttle like an ON/OFF switch or a ‘soft control’ similar to a volume knob on your stereo. (This describes how they operate not what the actual control is.)
Throttle – Can be a Twist Grip or Thumb Paddle. These have a tendency to be either ON or OFF.
P.A.S. – Pedal Assist Sensor is connected to your Crank & detects when your pedals are moving. These tend to be a softer assist adding power gradually when needed. The better sensors add power based on how much effort you are putting into your pedals while the cheaper units increase the power required at the touch of a button.
You will still need to operate the gearing on your trike to climb hills. Remember, for most systems they are an ‘Assist’ & not intended to turn your Trike into a motor cycle. This can be done though with much more powerful systems.
Which system is Better? – Either system works well with cost being within $200. of each other. The Crank Systems balance the weight better on your trike which is better for cornering. The motor in wheel systems can run quieter, keep everything compact & the noise behind you. Just be aware of the risk of tipping over on high speed turns if all the weight bei over your back wheel.
Batteries – Your biggest expense by far will be the Lithium Battery. With reasonable care they will last for 5 years or more so your annual operating cost becomes minimal even if you replace your battery after 5 years. Once you know what your Battery range will be just remember to halve that so you have enough power for the return trip home. On most systems this can be 50-60kms of assisted riding while still staying within your safe operating zone. You should aim for 80% of your batteries maximum capacity to get maximum life out of your battery. A guage on your Display will tell you how much battery charge you have left.
Most ratings for Batteries consider the battery exhausted once it will only charge to 70% of it’s maximum capacity so it is quite possible if you only make 20km trips your battery could last several years longer. Of course if your route includes killer hills where your motor is doing most of the work your range & battery life may not be what is advertised.
Should I choose a Hub Motor or Crank Drive? – This is a tough question to answer. Both systems have seen wide use in the E bike market from Manufacturers & After Market Conversions. I don’t see either method having any serious advantage over the other although the Crank Systems seem to be gaining wide popularity & becoming smaller in size plus balance your weight better.
How much power should I choose? – In Canada the legal on road limit is 500 watts. In the U.S. it is 750 watts & in most European countries it is 250 watts. I recommend a 350 watt, brushless, geared motor system as it keeps your weight low while still providing enough power for your assist going up hills.
How much weight are we talking? – The systems I install will add about 20 lbs./9kgs. to the weight of your trike. This includes the battery weight. While it may not seem like a lot, lifting your trike to load it into your car or muscle it through your doorway is enough to make you wish for something lighter or it could put your back out. Adding a Higher Wattage motor will increase the weight considerably as will adding a larger battery.
What kind of Motor? – There are 2 types of Hub Motors for in wheel installations. A Direct Drive Motor or a Brushless, Geared Motor.
Direct Drive Motors – tend to be heavy, large & produce less torque for hill climbing. They also make it harder to pedal your trike without any power being applied. This is a distinct disadvantage should you find yourself out on the road & run out of battery power or develop a fault. They usually cost less than Geared Motors.
Brushless, Geared Motors – are much lighter & produce more torque by use of internal gears. They tend to be a little more expensive than Direct Drive motors but will put less strain on your entire driveline & battery. Another advantage of the Geared Hub Motors is you can operate your trike without any, just a little or with maximum power applied. If you run out of power or develop a fault out on the road you can still pedal your trike home.
What about cost? – A complete system with 350 watt motor (In Wheel or Crank) with an 11 amp/hr battery. (Medium Range) installed in your trike will cost $1200 – $1400. Canadian
Click HERE to visit Mid-Island Trike Adventures!
Glen Aldridge explores the Canadian backcountry of British Columbia.