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Some of you may have seen my dog trike, in Edinburgh. I use it to commute between my home and the surgery with my two dogs, a Chesapeake Bay Retriever called Peta (a North American Native word for golden eagle) and a Hungarian Vizsla called Biba (short for Bibiana meaning lively). It allows me to keep fit by cycling, save money on petrol and lower my carbon footprint.
It is an adaptation of a cargo trike or Bakfiet as they are known on the continent where a human powered goods vehicle is a common sight in many cities. They have also become common in London, where they escape the congestion charge and can be used in wide public squares and can cycle right inside buildings to drop things off.
My trike is based upon a Gustav Werner “Transport” which I purchased from Henry Workcycles in Amsterdam www.workcycles.com. Henry Cutler, an American living in the Netherlands has an extensive, experience based knowledge of this type of machine and is very approachable.
I have the hydraulic disk brake model with the cargo 5 speed hub which is a strengthened hub gear compared to the normal 3,5 and 7 speed offerings from SRAM, and is specifically made for heavy duty applications.
The main modification I made was to fit a pair of steering dampers. I found the trike totally scary to cycle empty. I fitted a pair of generic motorcycle steering dampers described as “classic Kawasaki type” purchased through Ebay. This made a big difference and as well as damping out some of the influence of poor road surfaces it also minimizes the effect of my dogs lurching to one side on sight of a squirrel or rabbit on the cycle track. I exchanged the rear reflector for a 4D Toplight Permanent from Busch & Muller www.bumm.de . This battery rear lamp features a large reflective area as well as permanent rear and lateral illumination. This gives me a safe backup if the main electrical system is down.
The standard fitment rack is wider than standard at 170mm compared to a more normal 130-140mm. I found the Altura Dryline Rack Pack from Edinburgh Bicycle an excellent fit and an appropriate style. www.edinburghbicycle.com
I exchanged the standard saddle and pedals for a Specialised Mens Comfort and Shimano SPD pedal so that I would have the same contact points with my Giant Hybrid and my Cannondale Silk Road. Having tried the trike with the standard pedals, I would recommend a clipless pedal if you are used to them as it is simply far more secure, especially in the wet. It is easy and in my view safer to cycle with the tension in the SPD pedals backed right off. A scooter wing mirror completed the frame customisation.
I bought the trike without the box. Although the box is very nicely finished it was easier to start from scratch with a custom build. Some of the pictures show the first generation box and some are of the second generation box, which is lighter and more (a relative term here) aerodynamic.
I remade the box in birch ply. This is a much better grade of ply compared to the previous WBP having 9 instead of 5 plies. I routered away most of the centres area of the base, excluding the centre which rests on the frame. I reduced the height of the flat front and introduced a sloping detail to the sides. The rear frames are part of the overall box and the sliding door is made from the 12mm ply in lightweight aluminium channel. The box is slightly shorter at 1050mm which is ample for the Chessie which means a shorter front overhang and less steering instability when the dogs leap from side to side. I retained the use of reflective panels on all sides for visibility and have most of a large roll of the road sign quality, silver sheet. Email me if you would be interested in buying a piece. The slots at the back and top of the sides and top surface give an alternative hand position for riding without the assistance.
I chose to have a vertical sliding door on the left side of the rear face. This enables me to release and enclose the dogs without dismounting and gives me the security of knowing that the door is shut when on the move. In a very short period they have learned to jump in and out without assistance.
The drive system
I bought a Schlumpf Mountain Drive www.schlumpf.ch and a larger chain ring. This was fitted at Kinetics in Glasgow www.kinetics.org.uk. Ben at Kinetics has an encyclopaedic knowledge of unusual bike components, together with a superb fitting service and well worth the trip over there to have it done properly, first time. This has given me a higher top gear allowing me to approach the 15 mph speed limit for electrically assisted bi and tricycles and halved the bottom gear enabling climbing of steep gradients if the electrical system is down, with reasonable cadence and without complaining knees. An excellent piece of kit and definitely recommended.
Cycling laden with the dogs every day very soon became a real struggle and so I set about designing an electric assist. The recommended hub motors are expensive and I would loose my hub gear in exchange for a less robust, higher maintenance derailleur. Also, the motor would be expected to work from 0-15mph including getting the trike started from stationary. Having spent a fair amount of time on the internet, I didn’t find a turnkey solution so decided to make my own custom solution – my CHEsapeake and viSLA drive. For the CHESLA drive, the motor drives the left hand side of the cranks, just like for a stoker on a tandem. The motor would be geared down to suit my cadence range and means I am approaching 15mph in top gear.
I sourced a 24V 20AH Lithium Ion Battery from GBP Battery Co. Ltd in China. www.gbp-battery.com
I chose a UK made 4QD Porter controller www.4qd.co.uk/prod/ptr.html which was mounted with heat sink compound onto the aluminium motor bracket. I don’t need regenerative braking or reverse and the 50A capacity is more than ample. The battery condition meter and some of the wiring components were also supplied by this firm. The controller builds up to full power in 2 seconds and falls back in a second, which has proved ideal. It is simply and reliably controlled by a 5 Kohm resistor and a microswitch. When I want the assist, it comes in smoothly as I am pedalling and falls off quickly although not instantly, so you do need to continue to pedal for that extra second or two, something I do subconsciously, now.
The motor is a 250W geared motor from Unite Motor Co Ltd in China. www.unitemotor.com product code MY1018.
I fabricated a drilled aluminium bracket which would fit on the modified boom tube giving some fore and aft movement to tension the chain along with the tensioner. On the right side is the switch box and on the left side is the motor and controller. The motor comes with a 9T fixed wheel and I removed this and using a small brass interface piece made by one of my clients fitted a LHD 13T BMX freewheel.
I replaced the mountain drive cranks with a Thorn Power Pro captain’s crank set from St. John’s cycles www.sjscycles.co.uk. I removed the 39T timing ring and replaced it with a 54T ring and used a single speed chain (to accommodate the width of the teeth on the BMX freewheel).
I used an aluminium enclosure to protect a 30A relay and house the battery condition meter, step down to 12V module for the lighting and fuses. Most of these components came from Maplin Electronics. www.maplin.co.uk
The lighting system
One of the frustrations of the original trike was that the headlamps were often knocked out of position whilst the trike was in the garage in the surgery. Therefore I decided to go for integral headlamps. In addition to the vertical red reflecting strip, on each side of the rear face of the back of the cage, I wanted to add some rear flashing lights. I thought that this might prove a distraction when cycling and worked out that if they were about half way down the box and clear to those following, they would be obscured from my view by my hands. At this height, they were still comparable with the tail lamps on cars.
Most lamp units work on 12V and so I added a 1.1A, 24V to 12V adaptor from Maplin. The circuit was split into a headlamp circuit through the blue illuminated switch at the left hand grip and a flashing side light circuit through the red switch.
The headlamps are a pair of 45 degree beam 3W Luxeon MR16 Bulbs set into circular holes in the plywood using silicon sealer. Sourced from www.superbrightleds.com. Remember to include the sockets if you are purchasing. I protected the back of the bulbs with a small aluminium housing fabricated to suit. They provide an excellent light and although angled down to light up the road, the peripheral beam can be seen for several hundred yards.
The flashing front lights are a pair of 2 LED White Marker Lamps Black Frame from the Mobile Centre www.mobilecentre.co.uk.
The flashing tail lamps are a pair of M5 Series Truck Clearance Marker Lights from www.superbrightleds.com/truck_lights.htm. Again remember to purchase the sockets and the sockets need to be protected as I broke my first pair quite quickly with the dogs’ claws striking them.
Flashing lamps are much better for alerting vehicle drivers to a bicycle but I needed a high flash rate like that of bicycle lamps rather than car flashing frequency, which might have caused confusion., A solution was found thorough a vendor on Ebay. He was able to make me a solid state flasher unit with a customised high flash rate. It has worked flawlessly.
I use a bell on the cycle track but a bell is totally useless on the highway. Having seen the size and weight of a 24V truck horn, I purchased a moped 6V horn and connected a 5 ohm 50W wire wound resister in series from the 24V supply. Perhaps an air horn would have been better for some of the less observant drivers!
I used a lightweight veterinary fleece bedding on the floor, the same as we use in the kennels at the surgery. It is light, easily washed and non slip. I made some wooden hooks to fix it at each corner so that it is not displaced as the dogs jump in and out.
Transporting the trike
The trike is big at 2.4m long and 1m wide and just under 60kg and unless you have a long wheel base van at your disposal, a trailer may well be the best option. I have a 1800mm x 1200mm approx utility trailer and made a shoe on which to mount the trailer before lifting and sliding the whole assembly onto the flat bed of the trailer. This allows the trike to be loaded and unloaded quickly by one (reasonably strong) person.
Riding the trike
These trikes are nothing like bicycles to ride and you should plan some short acclimatisation rides at quiet times of the day, prior to using a trike in rush hour.
Lock the front wheels using the hand brake before getting on (and off).
Take a wide grip on the handlebars for maximum stability.
Expect considerable flex in the rear frame especially if you are a heavy rider.
Expect the odd feeling of being tilted over when riding on a cambered road. You soon get use to leaning the upper body to correct this.
Take corners very slowly until acclimatised. Lean the body into the corner to maintain stability. Put the inner foot down to help keep the weight on the inner front wheel. This is the opposite to a bicycle where you put the outer foot down as the inner pedal could strike the ground when leaning over.
Thanks to Henry Cutler for some of the above points.
Riding for Lepra
In a moment of madness I signed up to do a sponsored cycle ride in the trike. With the dog box removed, the frame made a good base for a sign board during the 68 mile Lepra ride from Edinburgh to St Andrews. It took rather a long time with no electrical assistance. I started about 90 minutes before the official start time and managed to get to Kinross before the first “roadie” caught me up. One surreal moment was cycling up that sharp hill after filling up with cakes at Freuchie. In bottom gear with the low ratio mountain drive range, I was down to about 2mph, so the regular cyclists without a low enough gear were actually walking past me cycling, much to everyone’s amusement.
Replacing broken spokes has been, unfortunately, the major down side of using the trike on Edinburgh’s poorly maintained roads and the proliferation of speed bumps has added to the spoke casualty figure, even at jogging pace. I decided it was time to junk the standard wheels and make up a front set with Hope hub, Odyssey BMX chromed rims and Halo BMX spokes.
On the rear, the rim failed on one of the speed bumps and I replaced it with a Mavic downhill rim and ST Swiss Alpine triple butted spokes with brass washers.
The higher specification wheels have performed much better remaining true with many fewer broken spokes despite the higher electrically assisted speeds ( higher speed being a relative term here!). If I were to start with a new trike, I would specify these high quality wheels.
I am now on a full second set of wheels with mileage and weather finally claiming the first good set. Again a bespoke set, this time made by one of Oak Tree’s clients www.harts-cyclery.co.uk
I am happy for any or all of the pictures to be reproduced subject to the following conditions.
1) That the use is not malicious
2) That the origin of the pictures is acknowledged.
All opinions and methods are those of the author, Alistair Marks, writing as a private individual and no guarantee or warranty is given or implied.
If my ideas have overlapped with those of others, I do not seek to infringe upon any existing patent nor profit from this article and place my ideas in a public forum for free (acknowledged, please).
I would commend the CHESLA drive idea to anyone with a tadpole trike, wishing to extend their range or capability.
I was spotted on my journey to work by a freelance photographer who asked my to take part in a photo-shoot. The results featured in four of the nationals together with a fair degree of editorial latitude, on the text particularly referring to the dogs being a staggering 20 stones between them.
The electric dog trike was the featured readers bike in the August / September edition of Cycle – the magazine of the Cyclist Touring Club. Please click here to see our press cuttings page.