eTikit Impressions

26 03 2010

eTikit's electric hub motor...

I’ll be posting all the gory technical details about the two electric motor kits Kurt and I are testing on two Bike Friday Tikits next week.  I’ve been a bit strapped for time so I haven’t managed to fit in all the testing I would like and I need to pull together all the numbers from Ken at Power in Motion to provide accurate specs on each system.

I have been riding the high power version of the eTikit kit on a loaner Tikit from Ken for a week now.  My rides have mostly been my short commute to work 2kms and some running around downtown.  While I haven’t tested the capabilities of this system to the fullest I do have enough experience to comment on how I feel about an electric Tikit and how I see it fitting in to my bike/transportation options.

I’ll admit I didn’t really “get” the idea of an electric bike.  Pedaling and exercise are the two things I really like about cycling so I couldn’t understand how I’d like a bike where you didn’t have to pedal??  I now realize that this isn’t a bike.  Ya that’s right this isn’t a bike.  It’s a folding electric scooter.

That may sound crazy, but when you look at it as a transportation device [not a bike] it’s fun to ride, it’s convenient, low cost and pretty darn cool.  It can replace a car/motorcycle and either be used with or instead of public transit.

I haven’t sorted out the range I’m getting from the motor/battery I have, but let’s assume I can get 15kms from it @ 30kph with no pedaling.  That gives me a pretty useful range from home to work with zero sweat.  I can add a transit leg in the middle to extend my distance.  If I ride the whole way to work I’m looking at 30mins to 40mins with a few lights.  I can fold the bike and take it in to my office and charge the battery while I work and ride home. I charge the battery overnight and I’m ready to rock in the AM.  No car, no parking no waiting for a bus. Less emissions. Less traffic. No noise. No license. No pain.  It’s a really great commuting tool.

I’ve used the eTikit to bomb home after work.  It has allowed me to cut my commute time by about 33% and arrive fresh.  I must admit I do pedal when in public just ’cause I feel funny using only the motor.  Perhaps that will pass???

Just to provide some basic stats I can cruise on flat ground at 30kph+ [35kph is my fastest electric only speed].  I can cruise up a moderately steep sustained hill in town at 19kph without pedaling as long as I pedal to get to that speed. I tend to leave my Tikit in 7th or 8th gear [out of 8] and pedal away from a stop slowly while giving full throttle.  The motor helps, but it’s not uber torquey so a little bit of effort on my part gets me to cruising speed faster at which point I can coast.

To be honest I can pedal the eTikit without using electric power, but it’s not fun.  You can feel the drag of the motor at each pedal stroke.  If I had to pedal the last 5km home once or twice a year it’s not a big deal. So running out of battery power isn’t tragic, but I wouldn’t be happy if that happen a lot so I’d make sure I had a big enough battery to get the mission accomplished 95% of the time.

Of course the beauty of a hub motor is that in less than 5mins you can swap in a regular Tikit wheel and ditch the battery to have a normal Tikit which is fun to pedal.  I think that’s very cool and it makes an eTikit a useful product for even a one bike cyclist who wants transportation Monday to Friday and exercise on the weekends.

Ken was smart to match an electric kit with a Bike Friday Tikit.  You don’t ever have to leave your e-bike outside at the mercy of thieves and vandals.  The Tikit design is clever and adding an e-bike kit to it that doesn’t impede the fold just makes it even more versatile.

Bottom line I “get” an electric bike now.  It’s not a bike replacement.  It’s a car/transit replacement.


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5 responses

28 03 2010
Chris

Hey cool writeup about the ebike. I am planning on building my own as well and have decided to try the “MagicPie” by goldenmotor.com. It is a pretty powerful kit and doesn’t look half bad when installed. Have you ever tried one?

2 04 2010
Matt

I was looking over your photo of the e bike and wanted to warn you to get some torque arms for your front forks. I was testing a hub motor last year and had both dropouts fail simultaneously! After looking into the problem I found that the sudden acceleration can put a lot of stress on the dropouts, especially if they are aluminum. We own two Big Dummies one regular and one with a Stokemonkey. After my catastrophic test ride with a hub motor I’ll stick with the monkey! Anyway, I love your blog. Thanks

3 04 2010
Charles Duffy

Some of the concerns (ie. drag from the motor) are specific to hub motor designs. Putting the motor in or near the bottom bracket gets rid of the drag when pedaling, and means that the motor benefits from the bike’s gears same as you do (so the low gears are ultra-torquey, the high gears *fast*).

Also, it’s hub motor ebikes that tend to be more pedaling-optional; the optimal RPM range of the motor in my Opti (a full-suspension ebike with the motor in the bottom bracket) is such that an 80-90 cadence is _strongly_ preferred, and you can hear and feel when the motor thinks you aren’t keeping up your end of the bargain (such that it’s time to pedal harder or downshift). Yes, it’s possible to ride an Opti without pedaling, but I never have — and the upside of this is not only that one’s still getting exercise while commuting (and getting “trained” by the bike to keep up a quick cadence, which I find I’m doing on my conventional bikes also) but also that between both batteries one can easily break 100 mile assisted range in 350-watt “economy” mode. (The Stokemonkey has been mentioned by another poster here, and using one of those without pedaling isn’t possible at all).

All that said — I think a hub motor is the right choice for the eTikit, given its nature and design constraints; even so, it’s well worth keeping in mind that different e-bike designs have different tradeoffs, and that what’s true of one isn’t true of them all.

10 04 2010
Matt

Here is another take on the folding bike with electric motor solution. It doesn’t have pedals but works in similar situations and folds up very nicely!
http://www.yikebike.com/

17 04 2010
Bike Friday eTikit Review Part 1 « The Lazy Randonneur

[...] Have look at my earlier eTikit post if you’d like more information on my overall impressions o…. [...]

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