Converting Electra Straight 8 w/ Bafang BBS02 750W & battery

[brickwall]

Hi,

I have an Electra Straight 8 that I've decided to convert into an electric bike:
- 24" rims with fat tires (equivalent of 26" with normal tires)
- Rear coaster brake and front hybrid mechanical-hydraulic disc brake (a TRP HY/RD that I installed myself)
- Shimano Nexus 8-speed

Here are some shots of the bike: http://imgur.com/a/nKz2e

I am a novice at e-bikes, but I am handy enough to repair a bicycle so the mechanical part of the install should go pretty smoothly. I weigh about 90 kgs and my budget is about $1000, and I want the highest possible speed and longest range that I can get for that kind of money. (It's obviously not a race bike by any means, but I still want it to be as fast as possible.) I'm going to use it occasionally for fun mostly, but maybe I'll end up not having to use my car as often.

I'm considering a Bafang BBS02 750W kit because I want to keep the original wheels and because I want to be able to use the drivetrain with the motor. This obviously means that I'll lose my rear brake, but the upgraded hydraulic disc brake at the front is very good. Here's what I've decided on so far:
http://www.greenbikekit.com/bafang-...t-48v-500w-750w-central-driven-motor-kit.html (with the C965A LCD)
http://www.greenbikekit.com/48v-20ah-e-bike-rack-battery.html

• What do you think about my choices, especially the choice of battery? I'm also considering a Samsung frame mounted battery, but they have much less capacity. They do however look more sophisticated and not as... "homemade".
  
• What do you think about GBK as a reseller? I originally intended to order from EM3EV but GBK is much cheaper.

I'm very grateful for any advice regarding this project.

 

[Willow]

Good bike ( I've done one myself)... good motor setup. But you definitely want to install a rear brake, and mount the battery within the frame.... not on a rack behind the seat.



I can make you a leather bag - but not cheap. PM if your interested.

 

[brickwall]

Good bike ( I've done one myself)... good motor setup. But you definitely want to install a rear brake, and mount the battery within the frame.... not on a rack behind the seat.

I can make you a leather bag - but not cheap. PM if your interested.

That looks really, really nice. I would prefer the battery to be inside the frame, since a rack would ruin the looks of it. There's also better weight distribution by keeping it within the frame. Not sure if the battery I linked to would fit inside. Will need to measure my bike. What kind of battery do you keep inside that leather bag?

I'll get back to you regarding the bag when I've decided on all the parts.

 

[Willow]

Pack is only 36V - 100 cells in all (18650 format LiIon). Could fit another 40 in there I reckon - there is a controller and switch etc in mine too.... which leaves less room for battery.

but at 36V with a 50Amp controller bike will still pull 2000W going up a hill. Top speed is about 40km/h. Capacity of my pack is 16AH - gets me close to 40km range, and it's hilly here.

I still have the lazer cutting file for the torque arms - which will enable you to also mount a disc brake on the rear...

 

[brickwall]

Do you have any close ups of the bike?

I'm not sure the rear break is necessary for stopping, but it would be nice to have a redundant brake if the front fails. There's a German company that makes a Nexus disc brake adapter but I'm not sure there's enough room for it on my bike

 

[Willow]

Rear brake is a must...