Cannondale E-bike Conversion

So I jumped down the eBike rabbit hole. We will see how much a pain this turns out to be.

The sacrificial victim is a 2015 Cannondale Trail 5 29er mountain bike. I bought it new and except replacing the seat it is original from the factory.



The Kit is from Bafang Direct USA (not affiliated with Bafang the manufacturer). It is a 750 Watt middrive motor and can be limited to 20 MPH. This will allow it to stay an electric bicycle under Texas State law and not an electric moped or motorcycle. This means no special license or light requirements to ride it on the road.

https://www.bafangusadirect.com/bafang-750w-bbs02-mid-drive-motor-and-battery-p/60.htm

I chose to upgrade to a 52V 17.4Ah battery to increase the range and make more efficient use of the available power.

The kit arrived today but I don't have time to start breaking down the bike. Tear down includes removing the crank assembly, front shift rail and front shift mechanism from the handlebar.

 

I like Cannondale bikes. They are very well built.
Sounds interesting, doing the E bike conversion.
I think this will be an interesting project.


Dave

 

I'm looking forward to following along with this build up. Let us know how you like it!

 

Okay, who the *bleep* designed the bottom brackets on these? And why would you have a self contained bearing insert that unscrews in the direction of pedal rotation?

Started the tear down at lunch and ran into that little gem. Luckily I realized it before I applied the 15 lb sledge to 1 ft long wrench on the removal tool.

 

I like bikes. My wife wants an ebike. Following.

 

i want a gas powered bike

 

Only because you’ve never ridden an e-bike.
They’re pretty impressive.

 

This always seemed wrong to me too, but there’s a good explanation for it: Technical FAQ: Are bottom bracket threads backwards? – VeloNews.com

 

The bike has all the parts stripped off that will be replaced or discarded. Both brake levers get replaced with ones that have sensors to cut power to the motor when they are activated. The front derailer/shifter is removed and discarded. Crank assembly removed and discarded. It gets replaced by the mid drive motor.

 

Mid drive motor installed and started running the cables on the frame. The motor is clocked up as far as I could make it without interfering with rear shift cable that runs along the bottom.



It keeps the center of gravity low. This kit does add about 30 lbs to the bike including the battery.

 

Looks like the pedals will be wider spaced than I am used to. Will see how that effects the ride.

 

Im in...been thinking of doing the same for a while

 

you dont get the rumbling of a 2 stroke with an electric motor... just sayin.

 

Hey, I get it. When I was your age, the first mod to any dirt bike was to remove the silencer.

I strapped my granddad’s hand-me-down post-war David Bradley chainsaw to my old banana seat, ape-hanger-handlebar bike, and used the actual cutting chain as the drive chain.

One thing I can say about getting older, I’ve come to appreciate stealth. Sleepers rule. Even if it’s on 2 wheels.

 

Spent my lunch installing the brake handles, controller display, thumb throttle, control pad and speed sensor. Just need to install the cranks, peddles and battery then I can test it. The battery is charging right now.

 

Everything is connected for testing. Need to straighten up the cabling still but time for the test.



And we have ignition!



Picked up the rear tire and gave throttle a quick blip. It ran perfect.

 

I am going to need a longer chain. The main drive is a lot bigger than what was on it previously.

 

All cabling is cleaned up and went for a quick ride. In the computer I set the tire size to 29 inch and restricted max speed to 20 MPH. I set the 9 speed rear cassette to 3rd to test.

With boost set to 9 it hit 23.5 MPH on throttle alone. On the lowest setting it reached 12MPH but much lower power draw.



Even with boost set to 1 (lowest), the bike feels light under pedal power. It is well-balanced and nothing feels awkward or ungainly.

The power cut off for the brakes works like it should. Even with the throttle held down, application of the brakes turns off the motor.

Overall really happy with it.