Electric Bike Terminology

Court

Administrator
Staff member
#1
Hi guys! I'm moving some content off of the main site and into the most relevant categories of the forum. This post was originally made on September 9th 2012:

Whether you’re familiar with bicycle terminology or not, the world of ebikes introduces important new concepts. I’m going to cover the old and the new here and lean on the infographic above to guide the conversation. Knowing these terms will make comparing electric bikes easier and you’ll end up with a better ride.

electric-bike-terminology-infographic.jpg

  • Hub Motor: this type of motor exists inside an enlarged hub and is built directly into either the rear or front wheel with special spokes. It drives the bicycle by applying torque directly to the wheel and is usually quieter and more efficient than external chain driven motors. Hub motors can be geared or ungeared and come in many Watt sizes.
  • Motor Watts: this is the unit of power defined as one joule per second used to measure the size of an electric bike motor. Higher Watt motors will go faster or be stronger but it really depends on the battery Volts too.
  • Battery Volts: this is the electric power potential the battery supplies to the motor giving it torque and hill climbing ability. Imagine a garden hose vs. a fireman’s hose. More water can come out at once from the fireman’s hose so that’s equivalent to higher voltage and will increase motor performance.
  • Battery Amp-Hours: this is the unit of electrical charge a battery is capable of holding and determines how long the battery will last. Higher Amp-Hour batteries will let the bike go further.
  • Brushed vs. Brushless: this describes how a motor is built, brushless is quieter because there are no “brushes” rubbing to make the motor go. Brushless also lasts longer.
  • Geared Motor: gears are used to convert higher rotations per minute (RPM) in the motor into more or less torque. Most bikes use gears but some cheaper bikes use plastic ones that may wear out faster over time or be noisier. Some bikes and trailers use chains and rings instead, like the gears on your bike. If gears are external vs. inside of a hub motor they may wear out faster because they are exposed to the elements.
  • Pedal Assist (PAS): electric bikes with pedal assist options sense the revolutions of your front crank, there is a small plate with magnets and sensors in it mounted right where your pedals go through the bike frame and every time the pedal goes by it signals the bike motor to help “assist” you. Many times these bikes have varying levels of assistance to either make your ride easier but use the battery faster or harder and have the battery last longer.
  • Twist and Go (TAG): throttle mode or twist and go mode is just the default electric drive mode that only powers the bike when you twist a throttle or push a lever. In this mode pedal assist is usually disabled.
  • Sealed Lead Acid (SLA): this type of battery is cheaper, easier to recycle and better for the environment and geo-political landscape because Lithium is often mined in unstable parts of the world. The downside is that the are much heavier and will only live for 1/3 as long as alternatives like Lithium Ion, most last somewhere between 300 and 500 cycles.
  • Lithium Polymer (Li-Poly): this type of battery is a step up from Sealed Lead Acid and will make your bike go further but also cost more. It doesn’t have quite as much surface area as Lithium Ion because the lithium-salt electrolytes that store energy are suspended in a polymer composite such as polyethylene oxide or polyacrylonitrile. The benefit is that this type of battery is very rugged.
  • Lithium Iron Phosphate (LiFePO4): this type of battery is another mid-level option that is stable and has a longer lifespan than Sealed Lead Acid. It is similar in performance to Lithium Polymer but may be heavier.
  • Lithium Ion (Li-ion): this type of battery is the most desirable because it offers the most charge cycles, close to 1,500, and is also very light. It is also the most expensive and has been unstable in some applications in the past. Newer Li-ion batteries are everywhere from cell phones to laptops and electric bikes.
There are so many parts to consider on electric bikes and this is just a shortlist. I will update it ongoing and appreciate any questions or comments below to include.
 
Last edited:

Court

Administrator
Staff member
#2
Following are some of the original comments that were made on that post:

JUNE MANION
I am a back country & mountain biker and was just wondering how you get on fording rivers with an ebike ? Or even the splashing going through shallow streams ? I would hate to drown the thing in the outback. Thank you

COURT
Hmm… Good question June, I think as long as you don’t fully submerge the motor or battery most ebikes can take a fair bit of rain, mud and even washing. I created this guide recently to cover the topic and hope it helps but each brand is a little different. Maybe carrying the bike over your head when fording a river? You could take the battery and front wheel off to reduce weight and take two trips?

MICHAEL PERNA
What is the proper setting for the pad disc sensor on the crank to be set on for no pedal assist at all it seems to have moved on me and now I can only use pedal-assist I have a bad leg can’t use the pedal assist only need turn throttle and go only that used to do it and now is not that silly little disc moved on the crank can you help me with the setting please I would really appreciate it sincerely Michael

COURT
Hi Michael, I will try to help you but need to know which make and model of electric bike you have? Sometimes you can unplug the cadence sensor. Not all ebikes even have throttles, if it isn’t working, maybe the throttle cable got disconnected or you aren’t in the correct mode?