We talk a lot about electric cars here but I haven’t seen much about electric bikes.
For as long as there have been bicycles and motors, people have been trying to attach motors to bicycles. As far back as 1914 you could attach a Briggs and Stratton “motor wheel” to your bicycle and get 25 mph and 80 miles out of a tank of gasoline. Pretty good for 1914.
Briggs and Stratton Motor Wheel circa early 1920’s. Wouldn’t mind having one of these.
E Bikes have been around for a while but have really come into their own in recent years. You can either buy one ready made or get a kit to convert an existing bike.
Ready made E Bikes come in a lot of different flavors. The vast majority are what I would call “commuter” or “city” bikes but I’ve also seen fat-tire bikes, mountain bikes, folding bikes, beach cruisers, cargo bikes and even high-end road bikes with motors built in.
This is a pretty typical electric commuter bike. Upright seating position. Fenders, racks and lights. 500 watt motor in the rear hub. Eight speed gearset which is probably plenty for the intended use. Manufacturer claims 50 miles range and 28 mph top speed. My guess is you can probably go 50 miles or 28 mph but not both. Weighs a hefty 55 pounds with the battery installed.
Conversion kits come in several flavors as well, which usually comes down to where to put the motor. Some motorize the front wheel and some replace the back wheel. Mid drive models usually mount on or under the downtube and replace your existing bottom bracket, crank and chainrings. Note that most of the “dedicated” E bikes are built as mid drives.
Typical mid drive setup. Good luck finding bike components that aren’t black these days.
So why get an E Bike? For commuters they might replace a car, at least during good weather. A lot of people would like to bike to work but worry about showing up at the office drenched in sweat.
For a recreational rider perhaps you ride with a group of faster riders and can’t keep up. Or perhaps you’re getting older like the rest of us and can’t go as far or as fast as you used to.
This was what led us to an E Bike. I am a much faster rider than the mighty Mrs. Kong. Nobody’s going to invite me to any races, but I can get out on a road bike and average 17-18 mph which ain’t too bad for a 58-year-old guy. I’m at that age now where I have to suffix everything with “for an old guy”.
The problem is, when we ride together she struggles to keep up and I don’t get a workout. The usual solution is to ride our tandem but the tandem is a lot to mess with and sometimes I want to ride one of my good road bikes. Some might say I have too many bikes, but the correct number of bikes is N+1 where N equals the number of bikes you currently have.
So an E Bike seemed like a good fit. Since she already has a nice bike I figured better to do an electric conversion on it. Less money and I won’t have yet another bike cluttering up the place.
I built his Soma Buena Vista for her a few years ago. It’s a comfortable ride but slow.
After doing some homework, a front wheel conversion seemed like the easiest way to go. I built this bike with a Campagnolo 10x3 drivetrain and I don’t think a Campy compatible rear wheel kit even exists. Note that those are possibly the only 10-speed indexed Campy thumb shifters on the planet. If you can find a set of Campy 10 speed bar-end shifters (good luck) and remove the mount they can be mounted on a downtube or thumb mount.
Likewise the mid drive conversion looked like a lot of work and I didn’t want to graft a black motor and crankset onto this pretty bike (ooooh shiny).
So back in November 2019 I ordered a front wheel conversion kit from a startup company called Swytch in the UK. It looked like a nice setup and I’ll let you know……….if it ever gets here. As of today (Sept 2020) I still don’t have it. Supposedly it’s on a boat from China as I write this but I’ll believe it when I see it. After waiting ten months I think their CEO needs to fly to Columbus Ohio with it in his carry-on bag and hand deliver it to me along with a personal apology.
This is what I was supposed to get. The battery pack mounts neatly to the handlebars. Maybe I’ll see it someday.
Out of frustration and a desire for my wife to be able to ride her E Bike before winter set in I ordered a different front wheel kit from Cytronex, also in the UK. The only hitch was I couldn’t get them to sell me a completed 650b (27.5 inch) wheel in silver. Instead I just ordered the motor and decided to build the wheel myself. This would also let me match the rim to the one on the rear wheel. To their credit the kit showed up at the house a week to the day after I ordered it.
I know how to build a wheel, but I had trouble with the spoke length calculation. Three different online spoke calculators gave me three different numbers. I took the motor hub to my local bike shop and paid him do the calculation and order the spokes for me.
Be nice to your local bike shop. He’s one of those people that lives, eats and breaths cycling but he’s also super nice and treats everyone the same whether you’re a club level rider or looking for your first bike.
On a side note, he tells me that the pandemic has caused such a cycling boom that he has a hard time even getting bikes to sell right now. I’ve heard the same thing from other bike shops. He says he’s even busier than he was before the pandemic.
The replacement front wheel with the hub motor. I used 2mm spokes for extra strength.
It took me about a day to build the wheel and once that was done the whole conversion took maybe an hour.
Everything goes together with zip ties, which I have not yet cut in this picture. Measure twice, cut once, and then realize you should have measured three times.
The Cytronex battery looks like an oversize water bottle and replaces one of your bottle cages. The battery can be easily removed for charging. They claim a full charge takes 2 ½ hours or they’ll sell you a fast charger than can do it 90 minutes.
One wire goes to the hub mounted motor. A magnetic sensor mounts on the chainstay near the rear cassette. Finally an LED pushbutton mounts on the handlebars to control the whole thing. Some of the fancier E Bikes can sense how hard you’re pedaling but this one only knows whether or not you’re moving the pedals.
The sensor has to mount very close (1-3mm) to the rear cassette.
It’s a pretty clean setup and not obvious that it’s an E Bike unless you look closely.
The finished product. Oooooooh shiny.
This setup is purely “pedal assist”. Start pedaling and the motor engages about a second later. Stop pedaling and the motor cuts out. Very simple.
Some E Bikes have a thumb throttle that allows you to ride without pedaling but not this one.
Some also have brake sensors that cut power to the motor if you apply the brakes. This one does not and to me they seem like added complexity. If I stop pedaling the motor shuts down and I can’t imagine any case where I’d be pedaling and braking at the same time.
The battery pack looks like an oversize water bottle and contains and LED charge indicator. The battery weighs 3 lbs 5 oz.
The button lets you select three different levels of “boost” or just turn it off and ride it like a normal bike. There is no noticeable resistance with the motor turned off.
The only control is this button. It changes color Green, Blue, Red for the different levels of assistance.
Be sure to check your local laws concerning E Bikes. This particular kit has a 250 watt motor and is limited to 20 mph for US customers (15 mph for the UK). The motor will only assist you up to 20 mph but you can pedal faster than that if you’re capable.
250 watts seems plenty powerful for a this type of application, where you’re mainly looking to go faster for the same amount of pedal effort. To get more power you need a bigger motor which means a bigger battery and more weight.
The Cytronex kit adds maybe 8 pounds to the bike. The battery weighs a little over three pounds and is easily removed. That puts the bike at 35 pounds minus the battery and 38 pounds with the battery. No lightweight but a good bit less than most of the commuter E Bikes.
The battery “bottle” has an LED that changes color as the battery level gets lower. Range is going to depend on how much boost you use and whether you’re climbing hills or bucking headwinds. They claim about two hours of riding on a full charge and I’d say that’s about right.
The motor itself is pretty quiet. I can hear it when I’m on the bike but I can’t hear it if I’m riding beside or behind the E Bike.
I was able to get 25 miles out of it at an average speed of 18.2 mph using the medium setting and still had some battery left. I think you might squeeze 30 miles out of it if you took it easy. I was easily able to top 20 mph on flat terrain which is something I normally would have a hard time doing on this particular bike.
The electric assistance is most noticeable on hills. I can keep up with the E Bike on flat ground but she’ll drop me easily on a climb.
It will take a small hill at 20 mph but on a long, steep climb (by Ohio standards) I had to drop to the middle chainring and gear down to 12-15 mph. Still faster than I can climb that same hill unassisted. Especially on that bike since I can’t really stand and sprint up a hill like I could with drop bars.
I haven’t noticed any traction issues with the front drive setup but I haven’t tried it on gravel or dirt roads. I think a mid or rear drive would probably be better if you were planning on building a gravel bike.
The triple chainring setup is definitely overkill with the motor. If you live somewhere relatively flat I think you could get by with a single chainring and possibly even a single cog in the back. There are single speed E Bikes on the market so I know it can be done.
If you get a little carried away and run the battery out miles from home like I did one time, it pedals just fine without assist. Other than the extra weight the bike rode like it did before the conversion.
If you think an E Bike might be right for you I can’t really tell you what to buy. I’m not shilling for Cytronex and I’m certainly not shilling for Swytch! There are a lot of different bikes out there and a lot of different kits. It all depends on what you want a bike to do and how much you want to spend.
If I was looking for a commuter bike to replace a car I might think about something more powerful than 250 watts. Some of those bikes are on the heavy side, however, weighing in excess of 50 pounds. One “fat bike” I looked at weighs in at a rather porky 75+ pounds!
Probably not something you’d want to haul up the stairs to your third-floor apartment. Our tandem doesn’t even weigh 50 pounds (48 to be exact).
This fat-tire E Bike weighs in at a whopping 75 pounds.
I can’t tell you exactly what the operating cost for one of these is. My back of the envelope calculation says a 250 watt motor running for 2 hours will use half a kilowatt. Depending on where you live that’s around 6 cents to go 25 miles or over 400 miles for a dollar, not counting maintenance.
That’s got to be about the cheapest way to get around. I might actually burn more money in terms of calories riding a regular bike.
Even a very fuel efficient car will use half a gallon of gas to go 25 miles, which is over a dollar at today’s fuel prices.
Prices for these things runs a very wide range. It’s kind of the Wild West out there right now with new E Bikes hitting the market all the time.
I’ve seen off-brand bikes advertised for around $1000 but I don’t know how good they are. There are some really nice looking ones from big name brands like Trek, Specialized and Bianchi but they’re in the $2500-$4500 range. Some of the electric road bikes even break the five figure mark!
If money was no object I really like the Specialized Turbo Vado SL which boasts 120 miles of range, a top speed of 28 mph a claimed weight of only 33 pounds. It’s priced at a hefty $4500, however, which is more than I paid for my airport car.
Got money burning a hole in your pocket? Trek will sell you a full-suspension electric mountain bike or a carbon fiber electric road bike for $12,500.
Nice bike but I’ve bought cars in my life for less than $12,000.
Speed costs money, how fast do you want to go?
It’s not quite like this but it feels pretty fast.
If you want a kit, a quick internet search will turn up several in different drive configurations.
Someone more knowledgeable than myself could probably just buy the components and put their own kit together. You would need a motor, battery, controller plus the various sensors (pedal and brake most likely).
I notice a lot of kits come from China with a 26 inch wheel, which isn’t as common in the US as in other parts of the world. I’d also measure your bike to make sure the motor will fit between your fork/dropouts.
I’ve seen kits advertised with up to 3000 watts (!) which I can only imagine would turn your bike into something more like an electric cruise missile. You might want to upgrade your brakes while you’re at it!
I’m not a lawyer but I’m almost certain that falls into “off road use only” territory. Don’t come after me if you bust your ass or get arrested for going 60 mph on a E bike.
Mrs. Kong says it’s a lot of fun and a good way to go faster but still get a workout. I think she’s enjoying me being the one struggling to keep up for a change.
