The only two terms listed above that I would want to change are ‘cogset’ and ‘shock absorber’. Although ‘cogset’ is technically accurate, I would refer to this gear cluster as either a ‘cassette’ or ‘freewheel’. There is a difference as explained here. Also, ‘shock absorber’ is what a front fork might have if it’s designed with a telescopic or suspension components (as most ‘mountain bikes’ are). There’s a good description of fork technologies described here.
One other item to note regards front and rear brakes. So often these days, and especially when we’re talking about e-bikes, you’ll see disc brakes which are discs mounted on the wheel hubs with brake calipers that provide the friction necessary to stop the bicycle. Disc brakes are often preferable to older rim brakes due to their stopping power, though when building your own e-bike, you have the choice to keep the older rim brakes or upgrade to discs.
Regarding brakes, my Build #1 bike uses a disc on the front (where the majority of your stopping power will be) and a rim brake on the rear. Build #2 uses disc front and rear, and Build #3 uses rim brakes front and rear. It’s totally you choice what’s going to work best for you and your bike.
So now let’s add electric bicycle components to our list. I’m going to borrow a few terms from Rad Power Bikes’ extensive glossary found here:
Ah
Abbreviation for “amp-hour”, which is a unit of electric charge that can be delivered by a battery.
controller
A large, black rectangular component that acts as the “brain” of the bike. The controller allows electrical components to communicate and controls the motor.
direct drive motor
A type of motor that has no gear reduction. It is more efficient at higher speeds, slightly slower when starting, and slightly quieter when riding. See also “gear reduction” and “geared motor.”
ebike
Short for “electric bicycle”—a bicycle that can use electricity, stored in a battery, to propel the bicycle.
geared hub motor
A geared motor located on the hub. See also “geared motor,” “gear reduction,” and “hub motor.”
hub motor
A motor located at the center of a wheel. Contrast with “mid-drive motor.”
hydraulic brake
A brake system in which hydraulic fluid, not a mechanical cable, is used to transmit the brake force from the brake lever to the caliper to slow the bike.
LCD display
The display on most models that shows various bike and trip details.
lithium-ion battery
An advanced, rechargeable battery technology that has a high energy density (a lot of capacity in a compact battery), no memory effect (the battery won’t be damaged with frequent use/charging), and low self-discharge (the battery will maintain its charge when not in use).
mechanical brake
A brake system in which braking force is transmitted by a cable mechanism.
mid-drive motor
A motor located at the center of a bike, typically between the pedals. Compare to “hub motor.”
motor cutoff
A feature that cuts off all power to the motor when a brake lever is squeezed.
PAS
Short for “pedal assist system,” a system that, when selected at the display, deploys power to the motor based on the rider’s pedaling.
pedal assist
A system that speaks to the motor to provide power based on the rider’s pedaling.
pedal assist sensor
The electronic device used to detect a rider’s pedaling. See also “pedal assist.”
regenerative braking
A method for converting part of the braking energy into a small amount of battery capacity.
Schrader valve
A common type of pneumatic tire valve.
step-through
A frame design that allows a rider to mount the bike with a low step in front of the seat rather than swinging a leg over the seat/ back of the bike.
throttle
A part at the handlebar that allows the rider to engage motor power without pedaling.
torque
A rotational force. Used to describe tightening a component or hardware to a specific value.
volt
Abbreviated “V.” The unit of electrical potential energy, or the difference of potential that would drive one amp of current against one ohm of resistance.
watt
A measurement of power.
watt hour
A measurement of energy used to describe battery capacity.
Now for a brief tutorial about power ratings of e-bike motors and why it’s important to make sure you’re buying the right motor and battery for your application. We spoke before about rear hub versus mid-drive motors. There’s a cost difference, and as I have yet to prove, there might be a difference in how the e-bike performs. I promised to let you know my thoughts in this regard once the weather warms a bit. But for this discussion I want to focus on the technical aspect of motor and battery choice.
Let’s start with what led to my choice of 48v 1000w systems. Power, range and cost were my three primary considerations. 36v (less power) and 52v (too expensive) fell off the list. 750w wasn’t much less expensive than 1000w, and I didn’t think I needed to go to 1500w+ for my application. What I didn’t factor into my decision was the ‘legality‘ of 1000w versus 750w systems. The might be a problem later on if they start enforcing power limits here.
Then when it came to batteries, I was just looking for a battery that had a good reputation and met my motor specs. I’m getting really good range out of my Joyisi 12.5ah battery, so feel that was a good choice for Build #1. For not that much more money the Joyisi 14.5ah battery is going on Build #3. Where I’m pushing 65 miles per 100% charge on the 12.5ah battery with the rear drive motor I’m hoping for even better range with the 14.5ah battery and the mid-drive motor. We’ll see and I’ll report my findings here. Keep in mind that I do a lot of pedaling when riding my e-bikes, so as they say, “your mileage WILL vary”.
I had also mentioned in a previous post about the importance of charging your battery to only 80% for the majority of its charge cycles. My rationale was to prolong battery life. Also, never store your battery for a long period of time (like over the winter) at either full charge or fully discharged. Either condition is bad for the battery. So, back to battery capacity, if you agree with usually charging your battery to 80%, then it makes sense to buy a higher capacity (aka 14ah or more) to get the best range when not charging to 100%. That’s my rationale and I’m stickin’ to it…
This new site has two primary purposes. First, it’s an exercise designed to help others develop their own WordPress websites. And second, it’s to communicate to aspiring DIY e-bike builders my best practices and resources that can help them successfully build an e-bike without spending a fortune.
