Those that follow my DIY e-bike shenanigans wouldn’t be surprised when I decide one day to replace a perfectly good motor with another, half the original motors power rating. Why, you might ask, would I do such a thing? Good question… And “because I can” probably doesn’t cut it as a reasonable response.
My primary motivation was to compare the 500w Bafang brushless, geared rear hub motor to the 1000w Voilamart direct drive rear hub motor. In theory, the 500w motor should give me the power I need for the type of riding I do, with less weight, and possibly improved range. Besides, I think the Bafang motor looks a lot better:
When replacing a motor with one from a different manufacturer, you’re not just replacing the rear wheel and motor, but also the controller, display and all the wiring. In addition to the motor and wheel, here are the other parts that got replaced:
Another fact of life when building (re-building) an e-bike is wire management. After mounting all the necessary hardware, this is the rat’s nest I’m left with to manage/hide/tidy up.
Using my handy Epessa bag I’m able to stash the controller in one side and store wires in the other. And although you might think this is some kind of magic trick, all those rascally wires tucked neatly into the Epessa and the end result looks something like this.
I need some more seat time before I write an informed opinion about the Bafang 500w motor versus the Voilamart 1000w motor. So far, I like the new motor a lot, and it does everything I ask of it. When I have a moment, I’ll snap a picture of the end result and add it below. I’ll also try to establish a response to the efficiency question. Is a 500w geared motor going to more efficient than a 1000w direct drive motor, or is it a wash?
And one last comment. In previous posts I refer to Federal and State laws that restrict where e-bikes that have a power rating in excess of 750 watts can be ridden legally. My 500w e-bike now falls well within these limits so can be used on trails where these laws apply. I’m thinking it’s a good thing to have at least one e-bike in my stable that’s legal. Now I just need to get a ‘Class 2’ sticker and I’ll be golden (just purchased, on sale today at Area 13, plus I just like supporting Kyle at Area 13)!
Here’s the final result, with just one more change planned for this week:
‘Final’ upgrade complete:
Before – Shimano Right Shifter SL-TX30-7R,7 Speed
After – SHIMANO Altus Right Shift Lever 7-Speed SL-M315-7R
I’m a big fan of the ‘Rapid Fire’ design used on the Altus shifter. It’s easier (and safer) changing gears without losing your grip on the handle bars than the XT30 shifter. Observant readers will also notice that I put the handlebar grips on backwards in the first picture. They’re still comfortable in this position, but installing them backwards is just wrong!
And one final picture of the handlebar layout, with all the necessary accoutrements.
** Update **
Well, after all that, I decided to put the 500w Bafang motor on the new frame (the whole story can be found here – Build #2 Gets a New Frame | RAT Electric Bikes). Which means Build #1 went back to being a 1000w Voilamart rocket ship. Here’s an image of the fully restored e-bike:
Adorned with its new ‘class’ sticker:
I’m guessing this e-bike will be pushing the legal limits on our local trails!