And Now, For Something Completely Different: Gearing Up To Build An E-Bike, Part 1

While some of the wood for the sewing table acclimates to my garage, I turn my efforts to another project.  We live on the outskirts of Dallenwil, about 2 km up the mountain towards Wirzweli.  The road is very steep and while I can get to work by bicycle in about 15 minutes, it takes about 30 minutes to get home again.  When it comes to bicycles, Monika has a very simple attitude toward steep hills; they make her angry.

While I consider the hill a workout opportunity, I can understand my wife’s perspective. If she didn’t have to think of muscling up that hill at the end of every trip, she would ride the bike more often. Hence, my Christmas present to her this year: a promise to convert her bike to an electric one.  It is time to keep that promise…..

I did some research and discovered that in Switzerland, e-bikes don’t come cheap (this was a surprise). The ones that are economically priced are like the old Huffys at Sears or Ace Hardware when I was a kid; heavy, and of cheap quality like this one:

Moving up the scale, a halfway-decent quality e-bike runs in the neighborhood of $2000-$3500 and still suffers from the “heavy” syndrome.  This is because even though the motor/electronics/battery meet the standards I’m looking for, often the frame is an after-thought and built like a tank in Taiwan.

From $3500-$5000 the quality of motor and frame are both in the range that makes me comfortable, unfortunately, the price gives me sharp chest pains and the sweats.

Another consideration, and of equal importance to the purchase price, is the on-going cost. A good comparison is the cost of printing at home; you can find a good quality computer printer for a reasonable price but they’ll get you in the end on the cost of replacement ink cartridges. The same goes for e-bikes if you factor in the cost of repairs/replacements from your local bike shop. Most people, especially here, take that as a matter of course however, I come from the land of Do-It-Yourselfers and more to the point, have spent most of my life learning how to do the things I couldn’t (or wouldn’t) afford to pay someone else to do. I wanted something that I could work on, and get parts for.

With current e-bikes, there are 3 main types based on the position of the motor, hub-drive (front wheel), hub-drive (rear wheel) and mid-drive.

I have decided on a mid-drive conversion, meaning that the motor is mounted at the bottom bracket (where the crank attaches) instead of being integrated to the front or rear wheel like many e-bikes.  This positioning improves the center of gravity and handling.  Also of importance, a mid-drive motor will not have to work as hard to get the bike up a steep hill. This will effectively extend the motor’s life.

Think of a hub drive like a single, fixed-gear bike, you can never change gears and the steeper the hill, the harder you work until your legs are exhausted (or the motor burns out). Because a mid-drive is attached at the crank, you keep the advantage of 8 or more gears on the rear wheel so when it’s too hard to pedal up hill, you shift down and pedaling becomes easier (both for your legs and, in this case, the motor). A motor that doesn’t have to work as hard, lasts a lot longer.

For Monika, the best part of this conversion (other than being able to climb that hill at 25 km/hr) will be that she gets to keep her bike which she really likes. It is an REI Novara Safari that fits her perfectly.

It also rides very comfortably since I replaced the original saddle with a Brooks Flyer S.

“Bum-comfort”: we’ve been riding Brooks leather saddles on all of our bikes since 2011 and will never go back to anything else. The ultimate test was a tandem trip we did from Passau, Germany to Vienna, Austria along the river Danube.  5 days at an average of 5-6 hours a day pedaling and we were so happy that we had those saddles. You’ll notice that Monika’s saddle on the left below (the Flyer-S) has molded itself to her bone structure. This doesn’t take long, and when it does, you are assured of comfort since the saddle now fits like a glove (so to speak).  My B-17 when new is on the right.  They last a long time too.

So, fast forward about 3 weeks of reading forums and e-bike blogs (a really good one is The ElectricBike-blog) and I settled on a company out of California called Luna Cycle.  It’s also cool that it has the same name as our family dog in Albuquerque. 

Luna

Luna Cycle sells motor kits and batteries for people with a few mechanical skills and a bike they want to convert. While I don’t like equipment made in China, I read so many good reviews about Bafang motor kits that I decided on the BBS02, a motor kit complete with drive gear, controller, thumb-throttle and e-brakes that cut out the motor in a braking situation. Add to that a 13.5aH battery and I was good to go.

The stock motor comes with standard programming for a Pedal Assisted System (PAS).  What this does, and it is quite counter-intuitive, is to increase motor power only when you pedal slower, and vice-versa.  I think this is not ideal for my wife’s situation because she really only wants the power for going up hills, not all the time.  Luckily, it is quite easy to disable the PAS in favor of a thumb throttle so she can use the motor when she wants.  In addition, the programming is capable of being modified in order to increase the maximum power. Let’s not tell Monika about that…..

New entry: having used the stock setup for some time now, we have decided that it actually works very well, so PAS is left enabled and a 25kph speed limit is programmed in order to remain legal (in Switzerland) as a regular bike.

Coming soon: shipping and customs.

 

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Sewing Center Part 2 – Wood Preparation, First Rough Cut

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E-Bike Conversion Part 2: Shipping and Bike Prep

2 Comments

  1. Sarah

    Should I be looking for a package in the mail. 😉

  2. Steve Bissell

    Maybe 🙂 but I have everything I need for this project!

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