I wanted to build an e-bike that:
- easy to modify.
- feel robust and secure.
- can be used as legal in Europe.
- with components that are easy to replace.
This blog post details all the technical aspects while I learn about electricity and how an e-bike works.
Aesthetic
I wanted a style between café racer and scrambler. There are some e-bikes in the market in this line, such as Super73 or P-51. I took them as inspiration.
Legality
It’s going to be legal in EU if you don’t:
- Don’t Excess 25 km/h.
- Don’t have a throttle.
- Total weight is less than 40kg.
- The motor only works if you pedal first.
Lights
Most of the e-bike lights are boring. I want to feel Mad Max during the night. I wanted something special, so I built something custom from motorcycle parts:
- Front: 15 LED Headlight.
- Rear: LED Tail Light + DC to DC converter.
Accesories
As much accesories as you can carry in your handlebar:
- Bell: Minimalistic inspired by Knog Oi Classic Bike Bell.
- Mudguard: Super73 RX fenders.
- Handlebar mirrors: CNC Handle Bar Mirrors.
Security
I will usually keep the bike close to me, but it never hurts to be cautious:
Tyres
I’m using Vee Mission Command, and I think they are the best in the budget quality/price/aesthetic, also offering a good mix of compose for all terrains.
Vee also Huntsman model oriented for e-bikes, and although they look great, they are 20% heavier.
Suspensions
The frame I got has a pretty decent supension:
- Front: KKE BF-34CS
- Rear: KKE BA-27RC
If you want to save money, having just front suspension is probably okay, especially with these wide tires.
Controller
The controller chosen is a KT-25A sine wave controller purchased at JN Ebike Store. These controllers are cheap, well-tested, and easy to find. Also they offer waterproof wires.
The KT-25A is rated for a 750W motor. My current motor is 1500W. I experienced that the maximum power delivered on my e-bike is around 1000W.
Ideally, I should to upgrade to one bigger (around 35A). I bought a KT 50A Controller (because it was cheap), but first, I would have to adapt the wires. Someday, I will, but not today. I have enough good for day-to-day.
Display
The display is a KT-LCD8HU bought at JN Ebike Store.
These displays are designed to be paired with KT controllers. There are different variations. One great thing about this color display is it allows tuning some parameters related to the motor.
Motor
The motor is also designed to be paired with a KT controller. In this case, the motor is a 1500W that fits in a fat rear cassette tyres. I bought it at JN Ebike Store.
Frame
I wanted a frame that feels robust on the road. After much research, I found marioebike was selling a frame pretty near what I wanted to achieve.
After I got it and chatted often with Brownie Wang, they finally designed another one with double suspension and a bit smaller.
Battery
My battery specs are 52V17.5Ah.
The max power my battery can deliver is 52V * 17.5Ah = 910 watt-hours (Wh)
If we estimate 1 mile costs about 20 Wh, we can estimate the battery range as:
910 Wh / 20 Wh = 45.5 miles = 73 kms
Conversely, the battery wattage directly relates to how much power it can deliver to the bike.
Note although the motor supports 1500W, the battery pack can deliver around 1000W. Expect an upgrade in the future.
I’ve tuned controller settings to work with 52v properly.
Wishlist
- Wheels covers – The bike looks amazing. I have to find a generic provider.
- Light pedals – How cool they are!
- Frame decors – They are aesthetic and functional. I need to find a way to do one.
Others
- YQ Bikes Store at Aliexpress – Doble suspension frame and more interesting parts.
- JN Ebike Store at Aliexpress – Motor + KT controller kits.
- BlurBoundaries & RAID DYNAMICS – bike accesories.
