The trip over to my local branch bank is, by car, just a little over a mile and a half or so, one way. Round trip on my Project Bamboo Zeus eBike is precisely 3.8 miles, according to Strava. I've made this trip many times before on my aging, but still very functional WaveCrest Labs TidalForce M750 eBike (circa 2001) and last Fall on the A2B Ferber. These electric-assist bicycles are equipped with 750W and 350W motors, plus substantial and separate battery packs, NiMH and lithium-ion respectively. I found the ride on the A2B much more pleasurable than on the M750, in part because the former is about 10 lbs lighter than the latter. Plus, it's more upright, Dutch-style riding position is also more comfortable. Both bikes are equipped with front shocks to help absorb the bumps and potholes. Both are also equipped with multi-gear derailleur systems if needed. The M750 uses a throttle for applying electric assist, the Ferber uses Euro-style pedal-on-demand.
By contrast, my Project Bamboo Zeus (PBZ) eBike is based on a single-speed hybrid frame imported from China by GreenStar Bikes in Minnesota. There are no front fork shock struts. The seat is classic road bike-style. The handlebars set low and forward. Like my M750, you lean over this bike.
The all-in-one Bike+ electric motor comes from ZeHus S.R.L. in Italy. PBZ is the first to combine both technologies. Its bamboo and aluminum frame is extraordinarily light by comparison at around 20 lbs.. The bike and motor together are 32 lbs. (13.6 kg). That's some 20 lbs (9 kg) lighter than the A2B Ferber, making it one of the lightest eBikes on the planet. I only know of one other, a titanium frame model by Prodeco Tech that also weighs just 32 lbs.
The terrain here in my community is 'hilly' - at least for Nebraska. Strava tells me there is a maximum elevation change of 169 feet along the route I usually take to the the bank. Even at about half the wattage rating of the M750, the A2B just seems to handle the grades with less effort on my part, even at the lowest power-assist rating.
PBZ is a different 'animal' comparatively. It's entire drive system is squeezed into a roughly 16 cm diameter hub: that's the motor, gearing, battery, controls, Bluetooth: everything. Where the average eBike battery might be around 400W/hrs, the ZeHus Bike+ battery is just 165W/hrs.
That left me wondering as I set up the level of electric assistance via ZeHus' smartphone App, how both the bike battery and I would fair. Would I 'run out of juice' on the way to the bank: meaning both the battery and me?
ZeHus engineered the motor's control algorithms to provide levels of assistance from full eBike to full bicycle. In their Bike+ mode, you theoretically never have to charge the bike's battery. It's much like how the Toyota Prius works. Your legs are the gas motor. Having spent much of the Winter so far siting on my backside, I opted to make my first lengthy run at a setting halfway between full eBike and Bike+. The battery was showing 89% SOC since I had charged it Sunday afternoon for the first time.
Having saved the power level setting on the motor using Bluetooth and started Strava recording, I set out for the bank with a strong quartering wind out of the west northwest. At the first positive grade, I had to stand on the pedals to make it. The M750 and Ferber let me take the hill with relative ease siting down. Yes, I pedaled on both, but the motors and larger battery reduced the physical effort by maybe half. At the midway setting on PBZ, I found myself working more. I certainly was breathing harder.
Maybe I should stop and reset the assistance level as I turned the second corner and up yet another grade. I resisted and kept pedaling, noticing that it also seems as if the motor was learning how I ride. I felt the effort ease up just a bite. By the top of the grade, I decided to leave the setting right where it was. I wanted to see how much battery it would take to get to the bank. There I would decide whether or not to call for more assistance.
There's really just one more modest grade before you hit a long level stretch to the bank. At the top of that grade, I knew I could make it at the current power setting. I was working harder than I would have with either previous eBike, but that's not a bad thing, especially at my age.As I usually do, I swung around into the drive-thru section of the bank, which I always find amusing, and deposited the check - yes, I should get that App that takes a picture of the check and electronically deposits it, but then I'd have no reason to ride my bike to the bank, would I? Parking out front to take the top photo, I check the battery level:75% SOC. I'd used just about 14% of the energy in the Boston Power cells on the ride.
Okay, that's not bad, I thought as I headed back south, now running parallel to 84th Street, planning to stop at the Post Office to pick up any mail. Now the wind was working with me and the grade is slightly downhill. While my average speed was just over 10 mph, at some point I actually hit 23 mph. Of course, the motor cuts out at 20 mph, so that was likely at some point briefly going down hill.
I sorted my mail, tossing some in the trash and headed back home. There I checked the battery again. 67% SOC. Curiously, when I just rechecked it, it's now showing 75%. I am not sure why. My friends in Milan likely have an explanation. Maybe the motor is learning how I ride. I'll ask and find out.
To be honest, I initially was unsure about the motor after a couple preliminary rides around the neighbor this past weekend. Yes, it provides assistance, but it's far less noticeable than other eBikes I've ridden. Or maybe its just more transparent. Case in point, one of grades climbing Centennial going East past the high school usually requires a fair amount of throttle on the M750. This time I pedaled easier than I thought I would have to given earlier inclines along the route.
In a word, I got a workout. My heart was pumping. I was breathing hard. But I actually don't object to that. The whole purpose of this experiment, which is costing me personally a not inconsiderable chunk of change, is to see if putting these two technologies together - the light-weight bamboo bike and ZeHus Bike+ all-in-one motor - possibly represents a viable product offering that fits between the conventional, non-assisted bicycle and a fully electric-assist bike. Serious cyclists love their sport and don't want it tainted by big, bulky motors and batteries. For those looking for a bit of a compromise, I think the pairing of these two or similar products is sort of a way to "have your cake and eat it too."
At least that's what I think I learned on this first test ride outside the immediate confirms of my neighborhood. I can see that the more I ride PBZ, the fitter I am going to get and hopefully over time I can move that power setting to ZeHus' infinite mileage mark.
For Strava fans, here's the map of my ride today.
Posted By: Bill Moore [26-Jan-2015]
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