Dictionary of Ebike Terms and Acronyms

[ebikemom]

Hi all,
Sometimes when I read this forum there's a term that I don't understand. Howzabout ebike experts and gearheads share their knowledge with all of us on this thread, by listing ebiking terms and acronyms, and sharing their meanings? THANK YOU, and ready, set ..... GO!!!

I'll start with an easy one that I didn't understand when I first came here ...

PAS=pedal assist

 

[Alex M]

Hard to tell how deep/shallow should we go in this educating endeavor.

Most acronyms on the list won't be Ebike-specific. Should RPM be explained? There are many electrical and mechanical terms out there, and many people who don't know - last time I checked, physics was not a mandatory subject in the great US of A or Canada. It's not enough to type Nm = newton per meter (for example) - you need to understand what this is.

Google is your friend. I just dialed "pas ebike", first 9 or 10 links explain what PAS is, and how it works.

 

[Mr. Coffee]

Okay, okay

Cadence sensing -- pedal assist based on how quickly you pedal
Torque sensing -- pedal assist based on how hard you pedal

-- both of those are technically not exactly right but are close enough.

Controller -- electronics on your e-bike that sits between the battery, motor, display, and pedals. Directs electrons from the battery to the motor based on pedal assist setting and the pedals.

LBS -- Local Bike Shop

Hub Drive -- when the motor is in the rear (and sometimes) front hub of the bike, and no motor power passes through the chain and gearing system of the bike. About 45 percent of e-bikers think this is the very best way to make an e-bike.

Mid Drive -- when the motor is (typically) in the bottom bracket and motor power passes through the bike chain and gearing system, just like the cyclists pedal power. About 45 percent of e-bikers this this is the very best way to make an e-bike.

 

[Alex M]

... "electrons" - tiny little things that you can't see and can't really repair, but they make it all work ...

I think it will be more correct to say that controller sits (i.e. physically connected) between the battery and everything else. That's why they call it controller.

 

[ebikemom]

We're on our way!
It's fine not to bother with generic things, but it can be fun to list them, also!

I have one to add:

Display--attaches to the handlebars and shows data gathered from the controller. Displays vary in how much they allow the user to program bicycle functions. The display is not the controller.

 

[ebikemom]

IGH="internally geared hub-drive motor"

 

[Mr. Coffee]

Thought of some more:

Watts -- unit of power. Power is defined as "work (energy) per unit time." Technically under the MKSA system (Meter-Kilogram-Second-Ampere) 1 watt is one joule per second. 1 watt is approximately the amount of power that an old-style incandescent christmas tree light bulb consumed. Electric bike motors are often rated in watts. This rating is never, ever to be trusted.

Ampere -- unit of current, defined under the MKSA system as one coulomb of electric charge per second.

Volts -- unit of "electromotive force". Best to think of it as "electric charge pressure". All other things being equal, and they never are, e-bikes with higher voltage motors will feel zippier.

Watt-Hours -- Unit of energy (or work). 3600 Joules. A typical e-bike battery of 500 watt-hours stores approximately the same amount of energy as two sticks of dynamite. Or a 10-piece chicken mcnuggets (that can't be right -- I can never keep calories and kilocalories straight).

Amp-Hours -- a unit of electric charge equal to 3600 coulombs of charge. Used to rate batteries.

 

[J.R.]

Sheldon Brown's Bicycle Glossary, A to Z

Hundreds of bike terms and acronyms with descriptions.

https://www.sheldonbrown.com/glossary-a.html

Two examples:

"BSD"

Bead Seat Diameter

The Bead Seat Diameter (B.S.D.) is the crucial dimension that determines whether a particular tire can fit onto a particular rim. It specifically refers to the "shelf"-like area inside the rim where the tire's bead sits.

The Bead Seat Diameter is the fundamental dimension used in the ISO/E.T.R.T.O. system of tire and rim sizing. This is the great virtue of that system, compared to all of the older systems that referred to the tire's outside diameter, with no specific reference to rim diameter or to the rim/tire interface.

_____________________________

"Headset"

HeadsetThe bearing assembly that connects the front fork to the frame, and permits the fork to turn for steering and balancing.
A headset consists of four races plus associated parts:

1. The crown race, which is pressed on to the bottom of the steerer, just above the crown.
2. The lower head race is pressed into the bottom of the head tube.
3. The upper head race is pressed into the top of the head tube.
4. The adjustable race attaches to the steerer.
   The adjustable race is secured by either a:
   • Keyed washer and lock nut, for threaded headsets or a:
   • Star fangled nut and cap, or compression rings in the case of some threadless headsets.

 

[ebikemom]

 

[Deleted member 18083]

SI Symbols (International System of Units)…

Here are a few comments on writing SI symbols – mainly relating to the use of upper or lower case. I hope the explanation will be both informative and interesting, especially if you live in a country that hasn’t adopted SI units.

• When a unit of measurement (amp, newton, volt, watt - written in lower case) takes its name from a person (Ampère, Newton, Volta, Watt), its SI symbol is written in upper case (A, N, V, W).
• The symbols for other units (gram, metre, second) are written in lower case (g, m, s). Local variations are permitted; for example, litre can be spelled liter or given an upper case symbol L (to avoid confusion with 1).
• Symbols are never followed by a period (except at the end of a sentence) or have an s (the symbol for second!) appended to make them into plurals.
• Most units can take a prefix to indicate a mulitple (k for kilo – thousand; M for mega – million) or a fraction (m for milli – thousandth; n for nano – billionth).

Some examples to use in the EBR Forum:

• m : metre (one of the seven base units)
• km : metre with the prefix k for one thousand
• km/h : kilometres per hour (always use a slash not a p for ‘per’)
• mm : millimetre; metre with the prefix m for one-thousandth
• Ah : amp hour **
• Wh : watt hour **
• Nm : newton metre **
• (** In maths equations separate the letters with a centre-dot or a space.)
• nm : nanometre; one-billionth of a metre (eminently appropriate for heated discussions about preposterously insignificant variations in tyre circumferences).

Wikipedia : International System or Units

… David

 

[ebikemom]

I didn’t know that Ampere was a person!!

 

[Deleted member 18083]

I didn’t know that Ampere was a person!!

From Wikipedia: André-Marie Ampère (20 January 1775 – 10 June 1836) was a French physicist and mathematician who was one of the founders of the science of classical electromagnetism, which he referred to as "electrodynamics". He is also the inventor of numerous applications, such as the solenoid (a term coined by him) and the electrical telegraph. Ampère was a member of the French Academy of Sciences and professor at the École polytechnique and the Collège de France.

The SI unit of measurement of electric current, the ampere, is named after him. His name is also one of the seventy-two names inscribed on the Eiffel Tower.

 

[ebikemom]

Great idea! This thread can serve as the foundation!

 

[Ravi Kempaiah]

Someone could make an eBiks version of this.
All they need to do is to point out: battery, display, controller, sensors, motor and anything electric related.

http://www.bicycle-riding.com/bicycle-riding/bicycle-parts/

 

[ebikemom]

How about this, @Ravi Kempaiah ? It is missing one very important part, however, the CONTROLLER!

http://e-bikeworld.blogspot.com/2016/06/anatomy-of-electric-bike.html

 

[Ravi Kempaiah]

How about this, @Ravi Kempaiah ? It is missing one very important part, however, the CONTROLLER!

http://e-bikeworld.blogspot.com/2016/06/anatomy-of-electric-bike.html

That's cool. There is some room for improvement for sure.

to explain the battery terminology.

Imagine your ebike battery to be like a big water tank with a hose.

Amp-hour or Ah: Width of the hose
Volt or V: height of the water tank.
(higher it is, more forcefully you can push the current through the motor resulting faster speeds)
(Also, to get equal amount of water, you don't need that wide of a hose if the height of the tank is higher (48V vs 36V)

Watt-hours or Whr: Water tank capacity


@Mikey- has a nice video on this.

Motor termnology:

Watts or W:

Pure power. (Imagine a sumo wrestler will have more power than an arm wrestler)

newton-meters or Nm: (But, an arm wrestler will have more torque than a sumo wrestler. 2-3Nm of torque is what is needed to uncork the wine bottle. So, you can imagine how much you may need to push the eBike).

This is perhaps the most abused and exploited term. Big Nm numbers are touted to lure customers but the real world dynamometer testing is very different.
A really nice video to explain some difference between HP vs Torque.

 

[harryS]

BMS, "battery management system" a safety circuit in an e-bike battery that shuts it off when it's outside the high and low voltage limits. Some BMS will also control peak current. Temperature shutdown is another optional feature.

Ampere, Volta, Coulomb, Curie, Ohm, and Newton of course, are among the people whose names live on because of their discoveries/research.

 

[Bruce Arnold]

SI Symbols (International System of Units)…

Here are a few comments on writing SI symbols – mainly relating to the use of upper or lower case. I hope the explanation will be both informative and interesting, especially if you live in a country that hasn’t adopted SI units.

• When a unit of measurement (amp, newton, volt, watt - written in lower case) takes its name from a person (Ampère, Newton, Volta, Watt), its SI symbol is written in upper case (A, N, V, W).
• The symbols for other units (gram, metre, second) are written in lower case (g, m, s). Local variations are permitted; for example, litre can be spelled liter or given an upper case symbol L (to avoid confusion with 1).
• Symbols are never followed by a period (except at the end of a sentence) or have an s (the symbol for second!) appended to make them into plurals.
• Most units can take a prefix to indicate a mulitple (k for kilo – thousand; M for mega – million) or a fraction (m for milli – thousandth; n for nano – billionth).

Some examples to use in the EBR Forum:

• m : metre (one of the seven base units)
• km : metre with the prefix k for one thousand
• km/h : kilometres per hour (always use a slash not a p for ‘per’)
• mm : millimetre; metre with the prefix m for one-thousandth
• Ah : amp hour **
• Wh : watt hour **
• Nm : newton metre **
• (** In maths equations separate the letters with a centre-dot or a space.)
• nm : nanometre; one-billionth of a metre (eminently appropriate for heated discussions about preposterously insignificant variations in tyre circumferences).

Wikipedia : International System or Units

… David

Beat me to it.

 

[6zfshdb]

A few more common acronyms often found in e-bike spec sheets.

LCD = Liquid Crystal Display. Type used on most e-bikes.
LUX=Unit of illumination. The amount of illumination provided when one lumen is evenly distributed over an area of one square metre. Describes the relative brightness of a light source.
LED=Light Emitting Diode. The type of bulb used in most modern bicycle lights.

 

[JRA]

IGH="internally geared hub-drive motor"

IGH generally refers to an Internal Gear Hub such as the Shimano Nexus models.

A Geared Hub Motor is an electric motor that has gears inside as opposed to a Direct Drive hub motor which is also known as a brushless hub motor that doesn't.

Another unit of measure is mAh:

"mAh means milliamp Hour and is a unit that measures (electric) power over time. It is commonly used to measure the energy capacity of a battery. In general, the more mAh and the longer the battery capacity or battery life."

Individual battery cells are rated by mAh such as 3000mAh. But when put in series/parallel they add up to total the amount of Ah's of the battery depending on the series/parallel configuration that is the total amount of batteries in the pack.