Monday, July 31, 2006

The cargo trike gets some help

Kyoto, sporting new rear wheel hub motor.

For a while now I've been pondering electric-assist for my cargo trike (aka, "drumtrike"). As with many heavy, load-carrying vehicles not much effort is needed to maintain cadence on flat terrain. Like a big ship in the water, once it gets going it's fine. But starting up, or worse, climbing a hill, and forward motion becomes a real effort. I can be pedaling at 15 kph, and then hit a small overpass or bridge and drop to 5 kph. Just slowly winch my way up and over while cars speed past and while beginning to sweat.

For instance, those familiar with Ottawa know there's an incline in front of the Chateau Laurier as Wellington St. rises up to Parliament Hill. You don't really notice it in a motor vehicle, and on a typical 2-wheel bike you just gear down a bit to get yourself over. But with Kyoto carrying me and 200 lbs. of gear it's a real effort to get up that hill at anything less than a crawl. My current Sunday gig is based at the foot of this hill. Great fun heading there, but I have do the grind back up (at least the big sweat happens after the gig, not on the way there!). On the 30C+ days we've had this summer I've occasionally felt a bit light-headed and / or nauseous from the exertion, and it's not a good feeling. And there are some other spots in town like this, like any time I head due west from my place, which requires going down the escarpment and then back up over the O-train tracks.

My friend Juergen, the guy who helped me build the trike (and did the welding for free!), has gotten into the electric-assist business. Check out his website: He is a member of EVCO (Electric Vehicle Council of Ottawa), and they are successfully lobbying the Provincial Gov't. to change the outdated laws that prevent electric (and e-assist) vehicles from being used on public roads. Juergen has been waving the e-assist carrot in front of me for a while now, and I have been resisting, mainly because I've wanted to try and make Kyoto happen under my own power. But while living car-free is a noble goal, as a drummer I still have this stuff to schlep around, and with pedal-power only I'm limited as to the distance I can go (in terms of time spent getting there), and what sort of shape I'm in when I get to the gig. It's not fun showing up to a wedding or corporate event drenched in sweat, then, after setting all the gear up, finding a place to rinse off and don the penguin suit and look presentable for the event.

So, if there ever was an application for e-assist, a cargo vehicle like mine would be it! Juergen had a sweet deal for me, so this past weekend I triked over to his place, and a Wilderness Energy BL-36 kit was installed.

20" (406) wheel with hub motor. The spokes were a bit loose, so they got tightened up.

Throttle, controller box, and kill switch (on brake lever)

Battery pack (consisting of three 12-volt, 7-amp hour SLAs), and charger.

Hub motor wheel, with zipties holding the wiring harness under the frame.

Throttle control installed. This was the most comfortable position, so the rearview mirror's bar-end mount was removed. I'll add on a bar-end that can fit into the open end of the handlebar.

Controller box mounted under cargo box. This was quickly tossed together, and needs to be re-done, as the box is partly upside down and its bottom is vulnerable to moisture.

For now, the battery pack just rests in the cargo box. A hole was drilled to let the pack connect with the controller.

I'm not using the brake lever that came with the legally-mandated kill switch, as it's for a canti brake, not the v-brake I have on the trike. For now it's mounted until I decide to keep this complete kit, and then wire the switch into the v-brake lever.

This kit was designed to be added to a standard 2-wheel bike. So adding it to a heavy cargo vehicle means it will have to work harder, and so we may have to modify as we go. While testing at his place, Juergen hooked in a current meter, and preliminary trial runs showed that with 200+ lbs. in the cargo box and adding full throttle made the voltage really drop. So when the throttle is needed I should ease into it a bit if I want the batteries to last the trip. This battery pack will be fine for a few kilometres of distance, but a larger pack will be necessary for more extended use (though of course that pack would be heavier...).

And so I headed home. I used the assist to get up one bridge a little more quickly (even though I had no cargo to carry, it's still a long slope and with motor traffic behind me why not get over it ASAP?), and again to clear a wide intersection a little more quickly (mainly just for fun). Otherwise it was pedal power as usual for the 6 km trip. The next morning (yesterday) saw the first trip moving drums. The goofy thing was that the hole I had drilled to pass the battery's cable to the controller was done while the battery was inside recharging (I was rather hot and tired). I had mounted the controller under the box quite nicely, forgetting the shortness of the battery's cable. Doh... So when I went to hook up the battery the next morning I realized I was not going to have assist on the way to the gig, as I had no time to correct my error! To add to the fun I picked up bandleader Steve's small PA set-up (in return for him picking me up in his van for long, rainy, or winter trips), so I had at least 2o0 lbs. to deal with. I got to the gig just fine (one short hill I just sweated up), and when I had a break I just snipped the zip-ties and moved the controller over to where it is in the photo above so that the cables could connect.

At the end of the gig I got the trike loaded up and made my way to the intersection, and then up that hill. The motor worked very nicely, keeping me a little more with other traffic, and also without feeling like my heart was going to explode. It does not really add to my top end speed, and while that would be helpful for extending the trike's range, I'll already gain travel time by not slowing to a crawl on hills like this.

The main drawback is that if the trike is being left unattended I must remove the battery pack and take it with me (on the Sunday gig the trike is parked in a corner of the plaza we play on, so no concerns there). The tiny 12-volt battery I've been using for the trike's lighting system hides in its small box, and that sometimes get left to Fate. But the big pack needs to come with me, and it's not something I'd want to carry around for any length of time. This will be even more so if I go to a bigger pack, so once I settle on things I'll look into building a locking battery compartment under the cargo box. Add 36-volts worth of solar panels and the batteries might be able to stay there! Hmm...

Oh, and while at Juergen's Kyoto got some tailgate stickers. The 'gate of course already sports the Kyoto "license plate", and a few weeks ago I also added a hand-drawn Flying Spaghetti Monster emblem. I think I'm becoming a devout Pastafarian. ;)

Many thanks to Juergen for his help in getting this assist concept together! If you think you need electric-assist for any of your bikes, he's the one to talk to:


Anonymous said...

I own the same blender as is featured in one of the photos. It makes a heck of a smoothie. :-)

Paul Bell said...

Hey Mark

I am sure the E-assist will grow on you. I know mine did.
You might find a slightly bigger pack running @ 48 volts will really transform the trike. I can possibly get you a 48 volt 14 Ah pack of SLA for around $140 tax in. Weight is around 42 pounds. Will check if you are interested as my contact is currently on maturnity leave :)

Love you idea of solar charging altho not sure how much charging you will get if you have any night gigs :)


Mark said...

Paul, Juergen had mentioned 48V to me, but said it might tax the controller a bit. He also mentioned the possibility of acquiring some larger batt. packs from a few sources, so we'll see...

And as for solar charging, true, night-time does have its drawbacks. ;o)

But I do have daytime options - during my Sunday gig the trike sits out in the sun for four hours, or I could just keep the panel at home on the roof of the covered "trikeport", and plug in when returning. Actually, making the panel removeable and on a long cable would simply mean taking if off when getting home, and moving it to the roof.

Anonymous said...

Aye dude, Is this a BL36 kit? and are you running it at 48 volts now? I also have the brushless bl36 kit and have been using it for the last 6 months and have about 1600 miles on it. Latley I've been thinking about upping it to 48 but with the design of brushless controllers and the fact that my first kit burst into flames before I ever got it working. I'm looking around to see if anyone else has done this before I burst it into flames agin. If you want to see my bike info you can look at

Only bad thing is 20 mph gets old fast. although I have hit 30 with this bike. that was however going down a slight grade with the wind and peddeling like I was on crack running from the bad boys! :)
I Thank You for any help you can give

Mark said...


I'm stil running 36-volt. Juergen has advised me that the controller is the limiting factor for going to 48V. It apparently can be done, but care must be taken not to always jump right to full throttle and overload the controller.

Alternatively, one could go to 42V using an additional 6V battery. I don't think you're going to find a 48V charger anyway, so you'll need at least a 12V charger to supplement the 36V. In my case I have a dual-mode 12V / 6V charger, so I can experiment with adding the 6V first. It won't blow out the controller, and might just give me enough extra juice. If not, then I'll have to go to 48V and be mindful of the throttle.

Anonymous said...

How is the trike on cambered roads?

Mark said...

It's got the same issues all trikes have in wanting to pull to th curb. It was quite annoying at first, because with the mid-pivot design I had the weight of the entire front half trying to lean over.

I installed old innertubes as bungee cords from just behind the pivot to just under the seat to keep the front end pointing forward, and this has made the camber issue much less bothersome (I should take a photo of those bungees some day).