So Alfie has ridden 41,932.27km and it was time for an upgrade… so I bought a Bafang 8Fun bottom bracket electric motor, fitted it myself (with the help of Klaus) and have now ridden with it for 300km. Here is the story of the motor fitting…
An electric motor? At my age??!!!
The first thing to say is, why the heck have I bought an electric motor? I’m only 44!!
I can blame riding-partner Klaus for this as he first started talking about it many months ago. He thought an e-motor would be a good addition to his trike, particularly as his SRAM Dual-Drive in the rear wheel has started packing up. He decided he would buy a new rear wheel with an electric motor in it (in place of the Dual Drive) and spent a lot of time looking at a website, elfkw, and choosing exactly what he would have.
Klaus and I cycle at a very similar speed on the flat, although he is way quicker on hills. I am possibly marginally faster around sharp corners but apart from that he is probably always a little quicker than me and our compared average heart rates show this when we ride together (his is usually 5bpm less than mine). No problem in normal usage, but if he had an e-motor I would never be able to keep up!!!
I started to think about them myself. I had previously said that I wouldn’t need electric assist until I was 60 but the more Klaus talked about it, and he talked about it A LOT, the more I started to think it was a good idea. But I would have to have a different option as I like my Alfine-11 hub gear and so wanted to retain the existing rear wheel set up. The only real option was a bottom bracket motor (where the pedals are). I began seriously thinking about this.
I emailed Neil at ICE who gave me some advice. ICE used to fit a bottom bracket motor (by Sunstar) but now only supply a rear wheel motor. However, Neil suggested I considered the Bafang 8Fun motor which he knew had been fitted to some ICE trikes.
Marc, a reader of this blog who also has a blog at https://etrike.wordpress.com/, pointed me to a thread on BentRiderOnline (a recumbent forum) from a chap who had done this very job on his trike… and there were some useful photos.
So a couple of months of googling, reading all about the subject… and then I saw a good deal on an 8Fun from China and pressed ‘buy’.
There are lots of different wattages – from 250 to 1000 watts – but European laws say maximum 250W with a cut out if you go over 25km/h. Bafang make 250, 350, 500 and 750 watt motors so the 250 is the weakest. Everyone suggested I went for a 350 or 500 but I was aware of the law and if I had an accident when using a more powerful motor than is legal I could be in a lot of trouble. I didn’t think it worth the risk so stuck to the fully legal 250W. It would also mean the battery would hopefully not drain as quickly.
This is what would come in the kit.
I had a few issues with delivery of the motor and its 12aH bottle battery – I was a bit of a numpty and didn’t realise I would have to pay customs and VAT on the motor. But it arrived in due course and the whole kit cost just a shade under 800€ – pretty good value!
And here is the battery and its holder.
I had done plenty of reading, as I said above, and realised I would need to buy a speed sensor extension cable as on most bikes the bottom bracket is very near the rear wheel but mine is a long way away. The cables are just 5€ each so I bought three (from Australia) as I wanted to make sure it was long enough. A good thing, too, as I needed all three.
Research had told me that I also needed a few other tools in order to fit the motor.
It was time to buy a proper bike toolkit – James has one in the UK but I didn’t have one here and they are good value on eBay so I bought a 44-piece bike maintenance kit.
I would of course have to remove the old pedals and bottom bracket and so asked Neil at ICE if I needed a special tool that wasn’t in my bike toolkit. Yes I did, a Shimano Hollowtech II tool (my bottom bracket was a SRAM GXP which is the same time) so bought one.
From reading the thread on BentRiderOnline it also appeared that a lockring tightening tool would be needed to stop the motor rotating under its own power. A Park Tool was suggested with this photo:
So I ordered the relevant tool, also some bar-ends (as I realised there would be a lack of space for the display unit), some new SPD pedals (as I was very unsure if I would get the old, silver ones off) and a new rear light for Alfie.
So everything was ready. Everything had arrived in the post and Klaus had booked a day off work to come and help me with the challenge of fitting the motor to my bike. We were all set!
Fitting the motor to the trike
Klaus and I have done lots of bike maintenance over the last year or so. With three trikes and a velomobile doing reasonable mileage there’s lots to do. We have moments of incompetence but also many successes and I tried to decide how successful we would be with this install.
My estimate was that fitting everything on the handlebars would be a problem but the biggest issue would be to fit the new brake levers (which have a cut-out for the motor) on the right hand side handlebar due to my Alfine trigger shifter. I reckoned that could take us two hours. Klaus was slightly more positive about our skills, but we both realised we were going to be using a lot of guesswork.
The day Klaus had booked off work was a bit damp. Rather than work in the cramped and cold garage I decided we would do the work in my lounge so I brought Alfie upstairs.
I had some large sheets of cardboard left over from last month’s furniture building so I laid that on the floor to protect it.
Klaus arrived and after a cup of tea and some biscuits we set to work.
Removing the old pedals and bottom bracket
First job – to remove the pedals and old bottom bracket.
Item one was to remove the screw from the left hand side pedal.
My special tool was put into service – it’s what the small middle bit on the right hand side picture is for:
But it didn’t fit!!! OH NO!!!!
Fortunately a standard large allen/hex/imbus key fitted this slot but it took us a while to find one large enough and long enough so we could exert enough force to unscrew this screw. I think it took fifteen minutes.
This was slightly worrying as this was literally the first step in a quite long procedure and it had been very difficult. I would not have been strong enough to do it myself alone. Possibly a bad sign.
But it was done, at last – hurrah!!!!
We had watched a video on YouTube about how to remove these pedals (or equivalent ones) – my iPad is hooked up to my TV and we watched several videos to give us a bit of a clue. So we knew that after removing the screw from the pedals we had to take out a little plastic widget and then pull the pedal off. It should just pull out. But did it?
We tried and tried and tried, including knocking it lightly with a hammer (we didn’t want to bend the medal of the frame at all so had to be super-careful).
Absolutely no luck.
Then Klaus suggested I check for videos on a Kurbelabzieher as he thought that would be a tool that might do it. So I found a couple and it seems there is a tool you screw into the pedal thread and then you can undo the pedal.
This is what we were looking at on the trike.
The YouTube video makes it look very easy – as long as we had the right tool. I said to Klaus, “Can you check if there is a Kurbelabzieher in my toolkit?” and he had a look and he said “no”. This was another major problem – we had now been working for an hour and only managed to undo one screw. There was nothing for it but to head to the biggest bike shop in Kempen and hope they had a Kurbelabzieher of the right size. I took the photo (above) with me to refer to in the shop and we hopped in the car to Metternich, the big bike shop on Vorster Straße.
They had two Kurbelabzieher in stock, looking very different to each other. One clearly wouldn’t fit, we hoped the other would and so bought it for 7€. The chap said that if it didn’t fit and we didn’t damage the packaging at all he would give us a refund.
We arrived back, having used 1 hour 45 minutes of our day to remove one screw. If this Kurbelabzieher didn’t work then the whole project would fail at this early point.
Fortunately it did work. Hurrah!
So the 7€ tool was used once, took about two minutes, and then I went to put it into my bike maintenance toolkit – at which point I noticed that there was one in there after all. And it would indeed also have fitted. So I now have two pedal removal tools, if anyone ever needs one!…
We tapped out the right hand side pedal (having split the chain earlier) and progress had finally been made… after two hours we had removed two pedals.
The next thing was to remove the bottom bracket. We prepared ourselves by watching another YouTube video and then offered up my special tool to the bottom bracket. Hallelujah, it fitted!!!!
Because it wasn’t very deep it kept slipping off but eventually Klaus managed to unscrew the bottom bracket left hand side. It was then a very easy job to remove the other side and slide the entire bottom bracket out.
And this is what was left.
We had been working for two and a half hours and it was now lunchtime – I had made a chicken biryani for us to eat so we took a break to eat it. I was wondering how much progress we would actually make today as I had choir at 7:45pm and Klaus would have to be home before that. And this was just the easy bit we had done! Still, the biryani tasted nice and we fortified ourselves with a few more biscuits before resuming.
Fitting the Bafang 8Fun motor
This was the easy bit – and it was really easy!
We just had to screw the chainring onto the motor (with the supplied bolts) and then screw a plastic guard on the other side of the chainring. This lot was then all slotted into the bottom bracket. Easy!
There was a lockring and a plastic cover. We discovered the difficulty of doing up the lockring, first doing it by hand and then using the special tool I had bought. Except…
The correct tool, which I had bought, is a Park Tools HCW-17. Here is a picture of one in action on a normal fixed gear bike:
And here is the picture of the tool from BentRiderOnline that I had seen:
Can you spot the difference? The nose is missing from the tool being used on the trike. This is because the motor fouls a bit of the frame. So we couldn’t do the lockring up as tightly as we wanted. Oh well, it’d have to do.
Once the lockring was as tight as we could make it we put on the black plastic cap.
The new pedals cranks went on very easily and we fitted the new SPD pedals to them.
That took less than fifteen minutes, but now we had the challenge of the wiring, the brake levers, the speed sensor, the thumb throttle and fitting the display and the on/off switch.
It was clear from the first moment that the power cable from the battery wasn’t long enough for my preferred initial position (on the back of the seat or in the sidepods), but should work from the water bottle holder area on the boom which would do for the time being although would mean there was rather a lot of weight forward.
Anyway, what was the bigger challenge was to get the old brake levers off and the new ones on. I was dreading this as I thought I’d have to dismantle the Alfine shifter. Fortunately the cable for the Alfine shifter was narrow enough that we could squeeze it through the small gap in the brake levers and fit them without completely disassembling the shifter. I thought that would be a two hour job but we managed it in ten minutes.
We then had to fit the speed sensor which is used to automatically power off the motor when going over 25km/h (this is a European law). We found a good mount for the sensor near the back wheel and had to use all three extension cables to reach it, but that worked fine.
The wiring for the Bafang is easy – there are colour-codes and it was dead easy to work out what went where. We fitted the bottle cage mount and the bottle and wired everything up.
My excellent foresight in buying bar ends was rather less efficient than I had thought as the bar ends were oval, not round, so the display for the motor didn’t fit on them. Klaus spent ages trying to work something out and eventually succeeded with the use of some cable ties. I knew I would have to order some properly round ones as soon as possible.
As we had removed the front derailleur (not needed, there is only one front chainring with the Bafang) we also needed to remove the JTek friction shifter for the gears. We could not undo it. But as we weren’t going to need it again Klaus collected a giant mole wrench (called an Englisch, in German apparently) and pulled the whole thing off. It looked rather sad and crumpled afterwards but wouldn’t be needed again.
We also fitted the thumb throttle and touched it briefly… and the trike rolled across the floor. It works!!!!!
The room was like a bomb site!
The fitting of the various electronic bits had taken hours, partly because there just simply wasn’t room on the handlebars for all the gubbins. I had to keep moving my existing bar ends (which I rest my hands on, and which hold the bell and mirrors) and we fiddled about with lots of options, but the main problem was that the on/off and motor assist level switch was on an extremely short cable to the display so had to be right next to it – and there wasn’t room. Oh well, something was cobbled together and so it was time to carry the trike outside and test it as it was already 6pm.
So we carried Alfie downstairs, got everything ready and I pedalled down the road – VERY FAST.
Wheeeeeeeee, it was great fun! A strange sensation but nice and quiet and it worked well.
After 100 metres I turned round and it was Klaus’s turn. He travelled a few metres, then nothing. Everything stopped. No power. Uh oh…
A quick look and the cables between the battery and the motor had come apart. So we tried to plug them back into each other but the two ends no longer reached each other. Why not???
We soon noticed – the motor unit had rotated under its own force and was just stopped by my headlamp. Clearly our lockring needed to be tighter but the tool was too big. Frustratingly we had to leave it there for the day – a bike with lots of wiring messily cable-tied to the frame and a rotating motor.
Still, excellent progress had been made and it was clearly going to work OK – if we could tighten that lockring up enough.
Frank to the lockring rescue
Frank my landlord is extremely good at mechanical things and when I showed him the problem (and the photo of the tool with the cut nose) he instantly set about fixing it.
The result had a sharp edge
So he ground it down a bit
Frank then used this tool on the lockring and was able to turn it at least an additional 180 degrees so much, much tighter. Since then it has stayed put so this was a success and well worth modifying the tool.
Fitting the battery to the trike
My reading of reports about motors on trikes suggested that battery placement is rather important for the handling.
Friend Kim, who fitted a rear wheel motor to her partner’s trike, had told me that having the battery on the rear rack was sub-optimal in terms of weight and centre of gravity when cornering. She wished she had been able to mount it much lower down.
Marc (who has etrike.wordpress.com) had offered this advice to me:
I got a battery on the boom of my second Sprint with the big wheels, but even while having a hub motor as ‘counterweight’ in the rear of my Sprint, the rear wheel gets awfully light when braking…
In your case, I’d mount the battery to the seat as well. It will help in preventing lifting the rear wheel while braking.
Don’t use the rear frame triangle to mount the battery! You don’t want the heavy battery attached to the rear swing arm!
If you can fit your battery directly under the seat, fine! Depending how the battery gets mounted into its frame mount, it will likely be very fiddly to take it on and off, though. Probably its better to just use the inner two cross beams of the seat and mount the battery on the left side under the seat. As near to the frame as possible.
He pointed me to this picture of one mounting possibility that he uses:
As mentioned above, initially the battery cable wasn’t long enough to have it anywhere but the bottle bosses on the boom, so that’s what I did at first to test the trike. It rode OK and the weight wasn’t too bad, although the back was definitely lighter (and it was a bit awkward to wheel it as when I lifted the back end up the nose wanted to really drop), but I did notice a very strong shimmy if I took both hands off the handlebars when riding at any speed. It happened within a second and was very strong, shaking the trike from side to side, so I had to always ride with one hand on (which is difficult when putting on gloves underway, for example). I experimented with riding the trike without the motor running – still shimmying. Then I experimented with removing the weight of the battery from the boom and riding along – no shimmy. So clearly the battery on the boom was unbalancing it.
Marc had sent me a few options of things I could use to attach the battery to the seat. I showed these to Frank who thought about it a bit (as always) and said he would get back to me as some of the eBay options would work out quite expensive. Frank had decided to use a piece of aluminium as a frame which would be attached to all three seat crosspieces.
Thus I needed three clamps to attach it to the frame and the nice clamps Marc had showed me were 16,50€ each. Ouch!
The first thing Frank did was to lengthen the cable for me so I could temporarily ride with the battery in my sidepods.
I took the trike for a 20km ride like this and it was fine but I had problems with the cable trailing out of the sidepod onto the ground and also the weight on the sidepods meant they kept slipping to the left hand side.
Frank of course had some kind of brainwave and produced these items for me a day later:
A piece of aluminium for the frame and three clamps that are something to do with sewage pipes (I didn’t enquire too deeply).
Here is a close-up of one of the clamps on the frame:
And here are all three, roughly in position.
The next thing was to drill holes in the aluminium sheet of metal to fix it to the clamps.
It looked like it would all fit, so the next job was to paint it.
After the first layer of paint had dried Frank decided to drill the holes for the Battery clamp.
Then it was time for the second and third layers of paint, black to match the trike.
Here is the framework in position.
And now with the battery clamp in place
And with the battery clipped in
Sorry for the mud in the pictures – I didn’t have a chance to clean the trike before my photography session. But it shows that the battery is liable to get a bit mucky in this position.
But I am currently riding without a rack on Alfie so using the sidepods which means the battery isn’t particularly visible.
Overall this battery mount seems to work very well. I can access the battery to remove it once I take the sidepods off (for charging – I don’t bother to remove it when parking the bike somewhere as I don’t leave the bike for long) and the weight distribution is good. I have, however, had a recurrence of the shimmy when riding fast on bumpy surfaces, but not at slow speeds. I don’t know how to prevent this but overall it isn’t a massive issue as I am aware of it, but it is a slight shame. Perhaps I will think of a solution.
Fitting all the gubbins on the trike
As mentioned above, one of the biggest problems with this installation (once I’d got the old pedals off) was fitting everything on the trike.
The kit comes with the following:
The problem for me with a recumbent trike was fitting the very large display to the handlebars. I didn’t feel I actually needed the display to be that visible and would have happily had it one the crosspiece of the frame or something but I did need the thumb switch with the + and – buttons to be reachable and as the cable was so short this meant that I also had to have the display to hand.
So eventually, once I bought some new bar ends that were actually round (although marginally short), I managed something. Initially I had the display on a bar-end at the top of the handlebars with the thumb throttle below it, but I discovered that I almost never use the thumb throttle but the + – buttons are very important so they are now at the top of the handlebar directly in the right place for my thumb.
With this photo you can see the display unit (currently off) with the On/Off and + – buttons to the right at the top of the handlebar. Below is another bar end with the mirror on and also with the thumb throttle next to the mirror.
You can see the cable from the Display unit disappears down the end of the handlebar (I have a plug sitting on the top which I need to cut away a bit so it fits better).
This is nice as it gets some of the cabling out of the way of my hands – there is nothing to foul them when holding the handlebars. Our first version of this, on the day I initially built up the motor, was much worse with two cables running down the handlebar where my hands were. But things were subsequently refined!
And here is a close-up of where my left hand is – with easy reach of the + and – buttons which increase the power assistance from 0 (off) to 9 (the maximum).
And this is what it looks like from the other side – spattered with mud, but it is December!
This is a close-up of the brakes in place.
As you can see, I not only have the usual brake cable but also an electronic cable. This is vital, as I will explain below.
The Bafang 8Fun is supplied with the cabling nicely colour-coded and it was easy to use. However, all those cables have got to go somewhere… and there are a lot of them!
The main cabling loom comes from the motor to an area where it splits into four (two brakes, speed sensor, display and on/off switch). On my trike this has to be slightly to the left hand side as the cable to the display is a little bit shorter than ideal for a recumbent trike.
And of course all these wires need to be attached to the frame. I have done it initially with reusable cable ties quite loosely and will sort everything out a bit neater when I have used the trike a bit more and decide what is best.
This is the main connector from the motor to the battery but I undo a different section when I take the battery out.
So this is the installation complete for the time being and pretty much how it will be long-term. Only time will tell if the battery is firmly enough secured in its current place and if there are any other issues.
How does it ride?
As I am writing this I have covered 300km in the trike with the electric motor. That is 25km with the battery on the bottle mounts, 35km with the battery in the sidepod and 240km with the battery on the seat.
As with most e-assist options, there are different levels of help that you can choose.
Setting up the motor software
The Bafang 8Fun comes with a display unit which shows speed, level of assistance, time of day, distance covered (total and trip), remaining battery capacity and also has a backlight. There were no instructions with the parcel I received of the motor and gubbins but the internet has the answer to everything and I found a manual on how to program the display unit here.
At the beginning you choose miles or kilometres, set the clock but you also have to set the wheelsize (it offers from 8 to 32 inches). I set this to 20 (my rear wheel is 20 inches) but after a short time of use I noticed that it was overreading my speed compared to the Garmin so I set it to 19 and it is much nearer the real speed. This has a bearing on its use because I have set it to stop offering assistance at 25km/h. This is the law in Germany (in Europe generally, I believe). The unit allows you to set the maximum at which it offers assistance as much as 40km/h.
One thing I have discovered, whilst using the motor, is that although it does indeed cut out at 25km/h, the thumb throttle has no such limit and if you use it without pedalling but using the gears correctly on the flat it will power me to 40km/h. The law says that e-assist such as this (that is not classed as a pedelec, i.e. needs special testing and you must wear a helmet etc) must only work when you are pedalling. So I shouldn’t use the thumb throttle on public roads/cycle paths (and I don’t). It is OK to use it when off-road though.
The unit offers also 3 gradations of assistance. There are three options:
Initially I tried 1-3 (there are only three different stages) but decided I wanted a bit more choice. So then I set it to 1-5. That worked fine on my own but when riding with Klaus I found I couldn’t quite match my speed to him; I was either a bit too slow on level 2 (say), or a bit too fast on level 3. So subsequently I changed it to the 9 options and that works really well. If you are cruising at 18km/h on 4, if you switch up to 5 you get about another 1 km/h. So on level assist 9 it is happy riding at 25km/h (at which point the assistance stops). With nine different levels I can easily just press the + button to give a little more help if I go up a slight incline and if I am running ahead a bit I can press [-] and slow down.
I knew when I bought this that gear changing might be a slight issue. This is because with the Alfine (as with a Rohloff gearbox) you have to briefly come off the power when changing gear. No problem when you are pedalling – you just ease off the power for a millisecond – but with an electric motor that doesn’t know what you are doing you might get a lot of graunchy gear changes.
I assumed that I would have to either stop pedalling (the motor takes about half a second to detect the cadence has stopped and to stop itself) or dab the brake pedal. A bit of experimentation, when riding with Klaus, showed the first option was hopeless as he nearly ran into me a couple of times. Stopping pedalling just takes too long and you lose too much speed.
However, the brake option is instant and doesn’t slow you down when it is just a tiny pull for a fraction of a second. At that point you change gear, and the motor kicks back in again a second later (it takes about a second to respond to the pedals turning). I am doing this with the left hand brake whilst the right hand is involved in gear changing and I have got pretty slick at it. I only mistime it very occasionally (which produces a jammed gear at the back or a nasty noise).
I discovered an error code when setting off one day – but had already read about this previously as it’s a common problem if the speed sensor stops working. Indeed the little magnet on the spoke of the rear wheel had twisted round. I put it back into position and everything was fine.
What’s it like to ride with the motor?
My first experience of the motor is that it is very quiet. It makes sometimes a weird rattling noise at a particular speed but changing speed or changing the assistance level fixes that. Otherwise it’s pretty quiet.
It gives you the feeling of riding with a tailwind when in the lower assistance levels. In the higher levels, when pulling away at traffic lights you can really feel it pulling you along.
My riding with Klaus has also shown some differences. We ride at a similar speed, as previously mentioned, but he said he has had to get used to me being a different speed. Previously he said he always knew where I would be and adjusted his riding to that but now I am unexpectedly faster. It will take a little time to get used to it. I did also initially find my steering seemed a bit less precise but I think this was because of the battery on the boom and that affected steering as that has settled down, but for my first ride with Klaus we had a couple of odd corners where I felt I got a bit close to his trike.
Klaus and I often compare our average heart rates when riding together. Usually mine is about 5bpm more than his but now that has changed – I seem to be ten or so less. I have also found that I definitely seem to sweat less as I don’t have to work as hard on hills.
The big issue with ebikes is battery life and range anxiety. I haven’t run any proper tests of course but I did ride 125km over two days using assistance level 5 mostly but with a fair bit of 9 and it was only at the end that the battery was too low, so that is a good sign. Further experience will show how well that goes, but at least the bike is still usable when the battery is flat although hills would be more challenging with just the large chainring at the front.
And what about Klaus’s electric motor that he has been talking about for so long? Well, he has put it on the back burner so it’s just me who’s electrified at the moment but this was definitely the best way round to do it – if he had gone electro before me I would have had no chance to keep up.
All in all I would say that this is a very good option for an ICE trike. The motor and battery cost £460 plus 150€ customs and tax. I also spent a bit on various tools needed to remove the old pedals and tighten up the lockring, but overall it was a very cost-effective way of giving my trike a new lease of life and allowing me to be a bit more lazy!
Thanks again to Neil at ICE for his advice, as well as Kim and others at YACF including Tigerrr who has electrified a few bikes, and of course Marc and his blog and his helpful advice. And to Klaus and Frank for helping me fit the motor and for not calling me lazy!