In January 2017 I set about electrifying my HPV Scorpion FS20 recumbent trike. Trikes are great fun to ride, and comfortable too. A lower profile and recumbent position mean they are more aerodynamic, but the downside is their weight. For me, it makes any climb hard going, even pretty innocuous lumps can take some effort. Of course, you can grind away in an ultra-low gear and, with three wheels to keep you upright, you can go as slow as you need to.
After looking at the options of a wheel drive or crank drive, I opted for a crank drive. Wheel drive kits tend to be cheaper than crank drives, but I find the crank drive a more elegant solution. And, If I ever wanted to sell the trike, I could remove the kit, revert the trike and fit the kit to a different bike, regardless of wheel-size. A crank drive will only have a single chainring, but my trike had that already, so it meant I could retain all 27 gears – a 3-speed rear hub gear with a 9-speed cassette fitted.
A Bafang seemed to be the obvious choice. Buying from China, where they are made, is a lot cheaper than sourcing one in the UK or Europe – there are plenty of providers on Amazon but the disadvantage is delivery times are much longer. As I was a bit sceptical about buying direct, I ordered a kit including a 15Ah battery from Woosh Bikes in the UK.
The Bafang kit is very comprehensive and easy to install, thanks to the fool-proof connectors. Instructions are not really needed, which is probably a good thing, as there weren’t any. For those that are doubtful, there are plenty of videos on Youtube about how to install a Bafang…on an upright.
The 250W Bafang crank drive kit laid out. Closest are the chainring cover, cranks and charger. Behind, the motor, spacers, battery with mounting bracket and locking key. Ay the back the thumb throttle, brake levers with sensors and the speed sensor are all connected to the display which has the control buttons permanently wired into it. Excuse the table cloth – I like to keep my workbench looking nice 😉The old BB – a bugger to get out!
First job was the remove the current bottom bracket from the trike. And there I hit the only real problem I had. Even with the right tools, I could not loosen it, so took the bike up the road to my local bike shop, where they dealt with it straight away.
To make working on the trike easier, I made use of our garden table and an axle stand. NOTE: If you want to be able to fold the trike after fitting, make sure there’s enough slack in the cabling to allow for the fold.Once the trike’s bottom bracket is removed, the motor with bottom bracket attached slides in from the drive-side. There’s a retaining bracket to stop the motor rotating within the bb shell and a lockring. Then the chainring and cranks can be fitted. The motor is a 250W one – the lowest power Bafang make, but the only one legal in the UK. Also to be legal you should not have a throttle that can drive the bike without pedalling, and the power must cut out at speeds above 25kmh/15.5mph.I wanted the battery hidden, mounted on the rear rack, so I fixed the battery mounting bracket through the bottom of a rack-bag, using a piece of plywood to the rack to fix the retaining screws into. The bag is supple enough to allow me to slide the battery off it’s mounting bracket and remove for charging and storage. There’s room down either side of the battery for some bits, like tubes and a waterproof etc. This battery has a USB socket, so I ran a 2 metre Apple iPhone charging lead from the bag to the front of the trike along with the power supply.The underside of the rack, showing the wooden mounting ‘plate’ fitting.As the kit is designed for conventional uprights, the wiring to the battery needed extending.The left hand steerer. The control button cable also needed extending, as I wanted the display mounted centrally near the front of the boom. Fortunately, the trike had cable operated brakes, so I could use the levers that came with the kit. They have sensors in to cut the power when either or both brakes are applied. If you have hydraulic brakes, you’ll need to buy brake sensors to fix to the hydraulic brake levers.I mounted the thumb throttle on the right-hand steerer. On the mudguard mount, on the left wheel is the speed sensor. Similar to a trip computer fitting, with a magnet fitted to one of the spokes, this small item needs to work perfectly. If the magnet or sensor move, and stop working, the motor will only provide power for a couple of minutes, then it will shut-down. I have since moved the sensor to the small bracket on the steering arm close to the reflector.There is quite a bit of wiring to keep tidy but a lot is hidden by the seat once fitted. I used lengths of cable management to keep the cables together. I got mine from Maplin, but there’s plenty on Amazon.Once it was all connected, I tested the unit before tidying all the wiring. To fix the display I used on old stem mounted onto the gear stump with a section of unused handlebar I cut down but have since put a lighter handlebar accessory mount in its place.Lots of zip-ties – but they do the job.Everything in place, I used bar-tape over the cables and wires to finish off the bars.
On my first ride out, the motor rotated within the bb shell, even though I thought I had it tight. That pulled on the cable and pulled the main connector apart, and I lost drive. It didn’t take long to sort out.
Since putting it together I’ve ridden several hundred miles without any real issues, though the connection (my extender) to the speed sensor became erratic because it had worked loose, so I soldered the joins rather than just wrapping them… something I should have done in the first place. For the larger cable extension I used plastic-housed screw connectors and wrapped all the connections in waterproof tape.
The trike in its form as at June 2020. I added an Airzound airhorn as I had one lying unused in the shed, but I also kept the bell for friendlier encounters, as the Airzound is loud and aggressive. Generally drivers give me a lot more space and consideration on the trike compared to any of our uprights.The Airzound is mounted to one of the seat tubes and the air tube has enough slack to flex with the steering.I mounted a small frame-bag on the boom to house my iPhone when riding, which is kept charged by a cable back to the USB socket on the battery.The arrangement at the front, with a plastic bar accessory mount holding the display. The headlight is connected to a bottle dynamo on the back wheel and the cable runs inside frame and boom.The flag is home-made. I bought some lengths of bright ribbon through Amazon and stitched them to a small plastic flag (also from Amazon) that is meant for kiddies bikes.
After coming back from a long tour of France I decided it was time to put a motor on the Pino. I had mulled it over for some time and, because a new ‘e-pino’ is horrendously expensive, I decided to fit a Bafang ‘Fun 8’ mid-drive motor. In the UK we are legally limited to 250W maximum power.
I bought the motor and battery together, from ‘Aliexpress.com’ and ordered it from China, as it’s cheaper than using a European supplier, but delivery times are longer. If you are in a hurry for the kit, a UK or European supplier will get it to you sooner.
The battery is a 36V 17.5Ah. Cable brake levers come with the kit but sensors for hydraulic brakes are available. The standard chainring seems to be a 44T but at a pinch and with an adapter plate, a 38T could be fitted. Larger rings are not an issue.
The left-hand Hase crank with freewheel and the motor sitting under the BB shell. The original battery lost much of its performance after 4 years good use, so the one here is a new replacement, but 13Ah, not 17.5Ah of the original.
The Hase crank has a square taper axle – in what I call a ‘square, square’ pattern. The Bafang cranks supplied in the kit are ‘square, diamond’ pattern, so, in order to retain the Hase freewheel, you need to source a ‘square, square’ right hand crank. These are available as a Tandem Captain’s crankset from SJS Cycles. You will have to buy the crankset, as they don’t sell individual R/H cranks.
The ‘Square, square’ hole in the Thorn crank matches the hole pattern in the Hase Pino freewheel crank. Our Pino is 2011. Hase may now use a different crankset, so it’s worth checking before you buy.The Thorn, right-hand crank from SJS Cycles and the 44T covered chainring. You can specify different sized chainrings but we’ve found, coupled to a Rohloff with 15T sprocket, it’s a good size that allows us to climb well and keep pedalling up to 25-30mph.The SW102 controller/display on the left bar. This is not the standard display that comes with most kits but there’s no suitable place for the stock display on the Pino, so I ordered this smaller unit. I added the lumps to the buttons, as selecting up/down on the unmodified rocker switch was tricky with gloves on. Changing power levels is very easy using one’s thumb on the up/down buttons. The cable goes down the inside of the bars for a tidy look. I used bar tape to cover the brake lever clamp as it was uncomfortable in its natural state.The display is very simple with just a power level (1-5), speed, odometer (which I never bother with) and battery capacity indicator. Holding the ‘Up’ button down switches on the rear light – powered from the motor. Our front light is permanently on from a hub dynamo.The thumb throttle at the bar-end on the right bar. I used a stumpy bar-end to support the Rohloff grip shift but as it is effectively on the left, I bought a left-hand grip shifter, so the changing order was not reversed, as it would be with the stock right-hand shifter. A second bar-end fitted lower holds a Topeak Dry bag for my iPhone which I use to navigate and track rides with. The charging cable is connected to a power bank in the pocket behind the stoker’s seat.There’s a lot of accessories on the bars. Left to right… Display/control, Ergon grips, bar-end, bell, 3 x water bottle cages, camera mounts front and rear, bar-end for phone holder and waterproof case, Rohloff grip shift on bar-end, Ergon grip, thumb throttle and mirror.The magnet mounted to the brake lever and the sensor, mounted to the brake lever body so that pulling on the brakes cuts the power to the motor. I used the very useful mouldable glue ‘Sugru’ for the job. It sets in about 24 hours, so a little tape was necessary to keep all in place while the glue set. The brake sensors were extra, but the cables fit in place of the cable brake levers supplied with the kit. All the cables on the kit have different colours for matching male/female connectors as well as different pin patterns, so it’s pretty well impossible to make a wrong connection. I have since replaced the hydraulic brakes with cable ones, and therefore switched the levers for the ones that came with the kit. These have built-in sensors.The wheel sensor and magnet on the rear wheel. These need to be fitted and aligned well, as if they don’t work, the motor will cut out after a couple of minutes if it’s not registering any rotation.
Extras
The Rohloff chain tensioner.TRP Spyre cable operated rear brake and Rohloff ‘click box’. I needed to fit the rear rack with a rearward extension to prevent my heals hitting the panniers when riding.Karon uses a Topeak cross-bar bag to keep a few items that are easy to get to.The original Spinner Grinder forks on the bike needed a thorough service so I removed them and replaced them with new Spinner 300 forks now supplied by Hase. These are actually about 20mm longer than the originals. With plenty of time, I stripped the originals, cleaned and re-greased them then put them aside. Recently the 300s became very sticky and inefficient, so I put the originals back on and have cleaned and re-greased the 300s ready for the next swap. It’s a 20 minute job to swap the forks.
Enjoying the August sunshine of southern france, near Marciac at the International Tandem Rally 2019.
Two and a half years into retirement and we are coping well. We celebrated no more work with a month of tandeming in Germany, down the Rhine, a week with the International Tandem Rally in Oberhausen an der Nahe, then cycling up to Lippstadt for an Army reunion, after which we headed back to the Rhine and followed it downstream to the Hook of Holland and the ferry.
Last year it was Sweden, but a bit too far to cycle we thought, so we drove, stopping in each place for a couple of nights so we could have a day ride before moving on. Sweden was fun with unusually warm weather – which was good – and the island of Öland perfect for riding, though the headwinds were a bit grueling at times.
In December 2018 I was fitted with a pacemaker. After a few years of bradycardia and arrhythmia the docs decided it was time. It took a while to get right, but now it’s settled and I’ve got used to it, I forget it’s there most of the time.
In spring 2019 we headed back to Germany to join Tandemtreffen (TT) for a weekend of tandeming. This was our second TT and just as much fun as the first. We hope to go again in 2020, which will be in the area near the Mosel river.
In the summer of 2019 we set off from home on the 1st July for an epic tour of France, riding to the Mediterranean and on to Toulouse before picking up a car to carry on the the International Tandem Rally at Marciac. After an enjoyable week of cycling within sight of the Pyrenees, we drove back to Caen, dropped the car off and caught an overnight ferry home.
As winter takes a firm grip and Brexit looms, I wonder what will pan out for us in the next few years.
