It has been a couple of months and a couple hundred miles since my last post. I really intended to update my blog more often than this, but it’s more fun to ride my bike (even when the errands are rather mundane) than to sit in front of my computer. However, there have been many ups and a few downs since November, so I will try to catch my blog up.
The Hammer Truck continues to be a great bike for us, and I owe you another post or two to describe some of its features. But it’s really the electric motor that makes the whole thing practical and fun in our abundantly hilly neighborhood. On the flip side, the electric motor has also been the source of a few challenges.
Our motor is the BionX PL-350, with a retail price close to $2000. I haven’t done a thorough comparison of different motors, but this one seems like it’s optimized for biking enthusiasts. It’s relatively lightweight, very quiet, and supposedly maintenance-free. But the features that really set it apart are torque sensor activation and regenerative braking.
Torque activation feels really cool when it is working the way you want. The system senses the amount of torque you are applying to your pedals, and it kicks in additional power from 35% to 300% of your torque. You determine how much assistance you want by selecting one of four assistance modes on the handlebar controller.
Regenerative braking allows you to reduce your speed and put some charge back in your battery while extending the life of your brake pads. There are 4 generation modes that increase the drag on your back wheel and put increasing amounts of electricity back in your battery. There’s also an option to activate the highest generation mode when you start to apply your rear brake. I really like that feature.
Pros and cons of electric assistance
During the first week or two, I rarely used anything but the maximum assistance mode (level 4, 300%). It’s frankly thrilling to blast up pretty steep hills at 10 m.p.h., to sprint away from stoplights as fast as most cars (at least until they shift!), and to haul kids around with less effort than going solo on my traditional bike.
With more experience, however, my strategy has become a bit more nuanced. Assistance level 1 (35% additional torque) makes the unloaded Hammer Truck feel like an average weight bike. It’s great for level ground or a light head wind. Levels 2 and 3 are good for moderate hills when I don’t feel the need for speed.
For a while, I was fiddling with the regenerative levels a lot. I would sometimes put it in a high regenerative mode and pedal downhill, reversing the direction of my battery meter by a click or two. However, one day when I was doing that, the rear wheel suddenly locked up. After some investigation, we found that I had shorn off the axle nut of the rear wheel. After that, I’ve been quite cautious about pushing the limits of this bike/motor combination. Since the motor wasn’t especially designed with a loaded cargo bike in mind, and since the bike wasn’t really designed to be motorized, and since our hill probably puts us in the 90th percentile of steep neighborhoods, I’m feeling that extra caution is probably the best course for now.
When you match the power mode to your legs and an appropriate gear on your chain-ring, the reward is great. With each stroke, you feel a surge of power, as if Lance Armstrong’s legs have been grafted onto your body. In power mode 4, you might be even better than Lance! It’s a beautiful marriage of man and machine – the kind of thrill you had the first time you rode your bike faster than you could run.
However, this is a great solution only for someone who likes to bike already. It’s not a moped! It works best when you’re putting in some effort yourself, not just coasting along and letting the motor do the work for you. As a matter of fact, if you’re not pedalling, the motor isn’t working either.
I spend a lot of time in my higher gears, even going uphill. Since the torque I’m exerting is pretty high, the motor is putting in a high level of effort as well. If I get tired and shift to a lower gear, the motor seems to scale back as well, so I end up going slower with only slightly reduced effort.
Once mastered, the combination of Hammer Truck and BionX motor enables many kinds of errands by bike. It extends your speed, your practical distance, and the amount you can comfortably haul. And of course, it’s fun – I look for any excuse to get on my bike now.
But is this the bike that will get millions of people out of their cars? I don’t think so. It’s a little quirky and the learning curve is a bit steep. Although it’s a good first step, the ultimate bike will be designed with an integrated motor from the outset. There are already a number of electric bikes in a traditional form factor. I haven’t seen a cargo bike with an integrated motor, and we may have to wait awhile for that. For now, this is a pretty good alternative to a second car for many of our errands.
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