|Thanks for a nice kit, it was easy to assemble. I got about 38km last night and had one green bar left so the range is good. Thanks for providing the small zip ties and bag, it is a very complete kit.
|I’ve had this tricycle for a while but now that I’m over 80 I found I didn’t have the power to pedal it up some of the hills around King’s Park. I rang up Matthew and he came over and converted it to electric. It’s absolutely fabulous now, I use it for a 14km round trip to get the shopping and for exercise. I absolutely love riding and this has now enabled me to get outside and do some exercise whilst being comfortable in the hilly areas. It’s wonderful to ride around King’s park and I don’t know how I managed without it. Thanks.|
A number of years ago I started Solar Bike with a goal to get electric bicycles running on hydrogen produced from algae. There are quite a few hurdles to achieve that goal but it is very possible. It was great to re-visit Prof Peer Schenk, who was my PhD supervisor 5 years ago, at the University of QLD to see the effort he has been making with algal biofuel projects. Many researchers often aim for very technical and highly engineered solutions. Peer aims for a very low energy and low tech solution; he is aware that the energy required to setup and run the operation must not exceed that which you can get from the algal biomass itself.
The top left picture shows some of the hundreds of algal strains Prof Schenk and his team have collected, isolated and grown up as pure cultures in the last 4-5 years. It is a very laborious and difficult task to isolate just one pure strain from a pool of murky water so it is an incredible accomplishment to collect so many strains and identify and characterise their potential practical uses. They often do mutational and selection studies in the laboratory to speed up evolution for higher amounts of oil or other products and then send these strains over to me at UWA to analyse for fatty acid content or other products. The top right picture shows one of their “mid-scale” growing bags that they use to keep stocks of pure cultures for times when the larger ponds get contaminated. The bottom left picture shows a small raceway pond, powered with solar panels, that is used to test both fluid dynamics with different pond designs and also strain ability to survive temperature fluctuation and contamination pressure. You can see from the picture this strain didn’t do so well. The bottom right picture is a much larger facility that is under construction. It is being used to test an extremely low energy input system for growing and harvesting algal strains – using nearly all recycled materials. It is situated on the Brisbane river and they will use brackish water pumped from the river into a top pond. The water will drift by gravity through a series of “growth” and “fattening up” ponds that will be driven by solar powered paddle wheels, then it will pass to a final gravity based settlement pond, the algal biomass will be harvested and solar dried on special mats. Depending on the strains that are growing, they have developed techniques to settle and harvest the algal biomass from the large volume of water. Low energy harvesting of algae from the liquid culture is perhaps the most challenging step to a successful system. It’s part a biological challenge, part chemical and largely an engineering challenge. As well as producing biofuel, another of their aims with this large pond they are building here is to produce algal biomass to feed cattle. Preliminary studies have shown an increase in growth performance using algal biomass. They are hoping to also produce beef that has high levels of the important omega 3 fatty acids that usually come from fish (fish get the good fatty acids from their algal diet). If any phytosterols accumulate in the animals then there is also potential for lower cholesterol and high omega 3 beef! You can see more of their work they do here: http://www.algaebiotech.org/
Good work Peer and team!
This is a Vanmoof bike (No 3) that I converted for the University of Western Australia’s solar-powered electric bicycle charging shed. It came together pretty well with only a few minor considerations. The first of these was the need for an additional set of front brake calipers because the original rim had drum brakes. Because the brakes didn’t then go around the mudgaurd I had to cut the front half off. It will function perfectly well but loses a bit of the original style. The battery holder needs points to attach to the frame and these were absent but a couple of hose-clamps worked well. The bike rides nicely when converted, it is very comfortable and easy to control. The 3 speed Nexus internal hub gear is adequate and works well for all motor powers between 200W – 500W, perhaps 350W would be best suited to the gearing and braking capabilities (legalities aside). The downside is that the bicycle is quite expensive, retailing for around $900. For this price a 7 speed internal hub is deserved. The good points are the frame – it’s awesome and looks very trendy, there are also internal LED lights within the cross-bar that can be charged with a USB – though not particularly bright. There is another model (No 5) that has an internal lock that is very handy but unfortunately rules out use of the tube battery due to space dilemmas. If future models come out with disc brakes, brigher LED lights and a 7 speed hub then it will be worth the price. It should also look better with silver forks and the mini-motor. In its current state it is a trendy, robust, unique and simple electric bicycle that costs around the $2000 mark for all components and delivery.
Matt, July 2012
This was an experiment to test the limits of electric bicycles – it’s an R&D project to one day enter the World Solar Challenge. I put together the most powerful electric bicycle hub, controller and battery components I could find. Selecting the bicycle took a long time. I needed something solid with a decent area within the frame for a battery but most importantly, a stable riding frame that could take the power of the hub motor. The KONA Unit was my choice because it has a plate that bolts to the frame that holds the axle (see here), a feature that would later become necessary. The Kona Unit is a Cromoly single speed 29er (see here for specs). Regular bicycles won’t be able to take the torque of high power and will strip the dropout. This happened to me after riding for 5 minutes with the 7mm aluminum factory plate – even with a regular torque bar installed. There’s no way a regular bicycle could take a few thousand Watts of power without being well reinforced. I made a 7mm stainless steel plate (pic here) for both sides that totally encloses the axle. This has held to date and will not fail. The next point of weakness is the frame itself around where the plate is bolted. The frame is built well so provided this isn’t under very harsh stress then it will also hold.
The motors can take more or less anything that you throw at them – or so I thought. My first effort was to get a rear motor with a 7 speed gear cluster. I powered this with a 72V battery and a 50A controller (theoretically 3600W of power). This went well until the rear dropouts gave way and the motor spun in the axle slot and severed the cables. Next motor, I opted for single speed as there was a higher rated option available and gears just became redundant anyway. With the same 50A controller and 72V battery the bike was extremely powerful and fast; quickly reaching a top speed of approximately 80km/h. It was only just possible to control the bike at this speed and definitely gets the adrenalin pumping but it was way too over-powered and you needed to be very gentle with the throttle. Eventually, when testing what would give first I took it onto the beach and up some sand dunes – really pushing all components hard. Finally, the wires between the motor and controller heated up so much the plastic coating melted and then something gave way within the motor itself – likely a Hall Sensor.
After blowing up another motor, a battery and a couple of controllers I believe the best solution for maximum sustained power with this sort of bicycle lies with a 72V 45A controller and 72V battery. The 50A controllers are a bit bigger and seem to give it extra grunt but the rest of the system doesn’t handle it securely – though this will improve soon. The 72V Li ion battery I’ve been testing it with successfully has a 15Ah capacity. This has allowed me to travel around 25km. With the slightly down-graded 45A controller I expect to get a bit over 30km. I couldn’t suggest using a lower capacity battery as the current drain will be too high and result in a short life or cut outs. I created a battery case from a wooden crate lying around work. Other mould options could be plastic, fibre glass and steel or aluminium. I like the wood though, just need a better carpenter. It should be possible to pack about 20% more battery in there to increase range.
The controller can sit well either below the frame for the larger 50A version or above the box & within the frame for the smaller 45A one. I tried controllers with sensors and ones without. Ones without the sensor are a bit more jumpy upon startup but more importantly they judder at high speed. For the extra potential problems with the sensors I think the performance outweighs their cons. I couldn’t test power outputs accurately because the system blew up my Cycle Analyst computer. Estimates are 3600W with the 50A controller and 3240W with the 45A controller (72V).
Future additions will be hydraulic brakes, suspension forks and a well crafted wooden box to hold the battery. Until you move to a country where laws allow you to ride something like this on the road then I suggest you find a good off road location to ride and get something properly designed from Stealth.
Matt – Solar Bike
This is one we thought would be good so put together at the bike shop. It’s the GIANT SEEK – a very robust flat bar road bike. It’s running a disc version 200W mini-motor and Panasonic 36V 9Ah cylindrical battery. The expected range is 30-40km. For this setup you’d be looking at $900 (bike), $1050 (kit) and $100 (installation), total = $2150. If you live in Perth then you can get one set up for $1800.
Available at Perth Electric Bicycles, Fremantle Woolstores. July, 2012
I purchased a 700C Mini Motor 200W kit and created the battery myself. The battery consists of two 18.4 volt 5ah lipos wired in series, giving a nominal 36.8 volts, but delivers 42 volts at full charge. I have been involved heavily with lipos for the last 4 years flying model aircraft and have dedicated high current lipo chargers. Soldering these batteries is not for the inexperienced. The batteries are model aircraft type from HobbyKing and cost about $43 each, so it makes for a very cheap 5ah pack. For long rides I can take another 4 spare batteries (two packs) in my bike bag and change them when needed. The 3 packs should give me a great range. On my first test with my first battery pack I got 53K out of it! It was a fairly flat ride but I used the motor on any rise in the road. Today I did another ride of 35K with quite a few hills and used 3,500 mah out of 4,600 and that was carrying the extra weight of two spare battery packs. These batteries are rated at 15C and will take a current of 75 amps continuous, so at the 15 amp current limit of the controller, they are having an easy life. The batteries just fit snugly into the tube, which is 65mm plastic downpipe from Bunnings. The battery tube holder is also made from 65mm downpipe and holds the battery tube very snugly but can be easily removed. The end caps are made from 65mm downpipe fittings. The removable top cap is fitted with a switch and a 25amp fuse. The holder is secured to the bike with four 5mm nutserts. The battery tube is painted white to keep the temperature of the batteries down. I started off with it painted black but in testing I found that in direct late summer sun the tube heated to over 45 deg C instead of 25 deg for the white. Both my wife and I are deeply in love with it!
I have a 12 km ride to work (24km return) and wanted to ride every day so my teenage daughter could share my car. After 12 months I decided that my 49 year old body was never going to be fit enough to ride every day so I started researching electric bikes. After months of internet research and test riding the two local electric bikes I decided on Solar bike. Solar bike appeared to have quality parts and battery, a reliable motor and I was confident Matt would be around to offer technical support should something go wrong or breakdown. I emailed and spoke to Matt at Solarbike several times and he was fantastic, always supplying the information I was after without pushing a sale. I eventually decided on the 200 watt mini motor with water bottle style battery. I originally wanted the carrier style battery for extra distance but they were out of stock and while waiting I changed my mind. In hindsight it was the best decision as the smaller battery is lighter and sits better on the bike and still allows me approximately 50 kms of riding. I started charging the battery every 2 days for convenience but I now charge it each night as I usually detour on the way home and travel over 30km and I don’t want to run the battery flat. Not being much of a bike mechanic I was worried about installing the kit myself but decided to give it a shot; I was amazed at how easy it was. About 2 hours and it was going, and that included putting the front wheel on the wrong way so the motor ran backwards. I have been riding every work day for 6 months now and am still loving it. Even on days when I’m feeling tired I know I can slack off and use the motor a bit more without worrying about hitting a headwind or struggling up hills. I also use the bike more for any short trips up to 5-10 kms. Many people have asked me what riding an electric bike is like, the simple answer is it’s like riding on flat ground with no headwind – all the time. I average about 27-28km/h on the flat, and about 20km/h up normal size hills. I’m 90kg’s and reasonably fit and I still get a good workout during the ride as the 200 watt motor needs a reasonable amount of rider input to stay at 28km/h. If you are over 90kg’s or not fit you may want to consider the 350 watt motor. I can confidently recommend Solarbike if you are interested in an electric bike. Thanks for the great electric kit.
Over the past 3 years I’ve purchased 3 kits from Solar Bike. The first 2 are always being used by family members. Recently, I decided to build a high power electric bicycle. I had been looking for a downhill frame but then I noticed the Phasor Prototype frame and the fun began. It has a Fox rear shock and Marzocchi forks, with 200mm front and rear travel. The bike produces 4000 watts and the battery has a 1.3 kWh capacity. The 100 volt battery can be charged in 1 hour. The battery was made here in Perth and the charger is a 1500 Watt Elcon charger. With moderate pedalling, I get 60-70 kilometers out of the battery. My commute to work is 46 km, so plenty left in the battery – especially if speed is kept to 30-40kms per hour with some pedalling. I have the controller in a position for airflow and also easy to touch to make sure it’s not too hot. I’ve had this bike up to 88 km/h on a slight downhill. The battery reads 100.8 volts hot off a charge and drops down to 94 volts after a 25km ride. It’s set to cut off at 84 volts for protection.
It wasn’t cheap but it’s awesome and I’m absolutely loving it. I paid the following for all the main parts:
$1500 Dual suspension components
$750 Kit (Motor, controller and throttle)
$2400 Frame (including postage)
|The Giant Roam (2013) is a 29er that is good for electric conversion (only suitable with mini-motor). If your commute to work involves a fair bit of stop-starting and up and down curbs then an electric 29er is a good option. A 29er is essentially a mountain bike but with the slightly larger 700c rims. With slick tyres, it makes a very handy and fun electric commuting tool. Bike retails for $600, electric kit for $1050.