Carting stuff uphill. It’s always caused headaches — and muscle aches.
Peter’s solution could be the cheapest, and most eco-friendly, yet devised.

by Peter Pedals
Nimbin, New South Wales

I know that there are many people living in the hills around Nimbin who regularly have to carry all their groceries and other purchases up steep slopes. The same may apply to hilly rural areas all over Australia. It is frequently not for the sake of getting themselves home, but to get their shopping home that people would put down concrete strips and/or purchase a four-wheel-drive vehicle. There is a much cheaper alternative, one that helps us become independent and less reliant on fossil fuel corporations.

This cart will take the shopping to places inaccessible to a four-wheel drive.

I was approached by a friend, who knew about my experimentation with pedal/electric transport, about using an electrically-powered bicycle to carry shopping up a steep hill. I pointed out that her hill was too steep to cycle up, that a bicycle is not the most appropriate device to carry a lot of shopping, and that walking next to it whilst trying to balance it and assist it up the slope is very awkward. I suggested that an electrically-powered two-wheel cart that you walk behind would be much more appropriate, and so I built two prototypes to prove to myself that the idea is indeed viable. I have used two 26-inch mountain bike wheels on each cart and an aluminium frame with a 12-volt battery, and either one motor that powers only one of the two wheels or a motor to drive each wheel. I designed the carts to hold a large black plastic chest with hinged lid, which is available from both Supercheap and was also available from Bunnings. This chest will carry pretty much everything that will fit in a boot of a small car. I also managed to get a black plastic wheelbarrow-type tray to fit on it for carrying rocks, soil and even a lawnmower.

I have tried it out and found that I could carry quite large loads up a steep hill without a huge amount of effort. Large rocks, ditches and very long grass on the track still present a problem, especially with the single-wheel drive. We decided to cut the tall grass to see how much difference short grass makes. In this instance it was easiest to push the mower down hill to widen the track, but hard to drag the mower all the way back up the hill. Of course, the shopping cart could even carry a lawnmower up the hill when the lawnmower’s own wheels are too small to easily push up a rough track.

Comfortable walking speed

The trick with the powered handcart is that it must be propelled at a comfortable walking speed using a motor designed to propel a bicycle at a fast running speed. Using a 24-volt motor, I thought a good start would be to supply it with 12 volts instead of 24. But this was not enough, the gearing needed to be much lower than for a bicycle. From a company called Eazyride you can purchase a 42-tooth freewheeling chain ring (sprocket). I got two of these and two 52-tooth chain rings from bikes I got from the tip. I bolted the 52-tooth chain rings onto the 42-tooth chain rings and mounted these onto the wheels. The thread on them is the same as on the standard bicycle clusters. The 250-watt bicycle motors were purchased from Oatley Electronics (www.oatleyelectronics.com) and come with a nine-tooth sprocket. With a 12-volt battery this now got it moving at a steady walking pace. I used a circuit breaker as an on/off switch, but the problem with that was that it would start with a jerk. So I decided to make it 24 volts after all and got a 24-volt 500-watt motor speed controller from Oatley Electronics and a lever throttle from Epac (http.//epacpower.com.au). The controller has a half-speed setting which I employed. I could now go at any speed and start smoothly from a stop. I used two 12-volt 10Ah sealed lead-acid batteries connected in series. Lithium ion batteries would be a lot lighter, but also more expensive.

I am very pleased with my powered handcart. All I have to do is walk behind it and guide it. It will get to places where a four-wheel-drive car won’t go, and it doesn’t incur the fuel costs, the expensive vehicle maintenance or the amount of road maintenance required from driving a vehicle on a dirt road. And it’s a lot cheaper to start with.