My Conversion Project: Part 1

morphix

Esteemed Pedelecer
Oct 24, 2010
2,163
119
Worcestershire
www.cyclecharge.org.uk
As my first ebike conversion is now finished, I decided to do a write-up about it which some of you may find interesting, perhaps even helpful.

Background and reasons for doing a conversion

After test-riding an electric bike last November and being impressed by ebikes, (but not by the prices), I decided to have a go at doing a conversion. I'm not the most mechanically minded person, but after seeing some of the conversions in the forum it inspired me to have a go. It looked like a lot of fun and considerably cheaper. What also appealed to me about doing a conversion is that you can choose the ideal bike for you, and then convert it in a way that suits your own requirements, both in terms of how the bike looks and functions.

Choosing the kit

I started this project by choosing the kit. I had seen Vitenso kits mentioned in the forum and after checking them out at rftec I knew right away that was the kit for me because it had an LCD console and I'm a sucker for gadgets. Although there weren't any reviews or forum appraisals of the kits, some of the parts (the motors and LCD) had been used by other notable manufacturers, so I decided the kit couldn't be all that bad and decided to go ahead and order one at 330 euros delivered. That was without a battery. The batteries were available but the cost was off-putting to say the last, at 400 euros..it seemed over-priced to me. I had already heard in the forum about cheaper batteries being available on eBay directly from China, so I decided to come back to the battery question later.

The motor in the kit (2.3kg) was supplied spoked into a wheel. I opted for a front-wheel kit as it seemed a much simpler way of converting a bike from what I'd read. The motor and controller are 36 volts 250 watts rated. I considered 24 volts for the smaller battery sizes, but got the impression that higher voltage is better for ebikes if you want decent performance.



Choosing the bike

Choosing the right bike was quite difficult and I spent about a month looking at different bikes. I live in a second floor flat, and I had decided that I would not be storing my precious ebike in the outside shed. So it made sense to get a folding bike so it would be easier to carry up the stairs and easy to store away in a cupboard without taking up too much space. Obviously the lighter the bike the better too. Initially I looked at Dahon, Raleigh and some other branded bikes but they were all rather expensive or too heavy or just not quite right in how they looked (I'm a fussy bugger!). I finally decided on the Dahon Espresso, a 26" folding bike which I knew converted well. Then just as I was about to purchase one I saw a company called Bicycles4u offering bikes with a frame style similar to the Espresso for £150, so I decided to get one and check it out to assess whether it could be converted.



Modifying the bike

The bike itself had a similar spec to the Dahon Espresso, Shimano 21-speed gears, 26" wheels, V-brakes, folding pedals, quick release saddle, but obviously lower spec components. The bike also weighed 14.5kg only 1kg heavier than the Dahon, on account of having a steel frame as opposed to the Dahon's aluminium alloy. I figured a steel frame would be better for electric conversion with stronger forks. I set about upgrading the bike and fitted a nice comfortable saddle, some comfortable ergonomically shaped grips, and then later I replaced the inner tubes and tyres. The 21-speed gears seemed unnecessary on an electric bike, and the two gear shifts took up too much space on the handlebars. I needed one side free for the throttle and LCD console. So I decided to remove the front gears, leaving the bike with 7 gears operated by a twist gear shift on the right-hand side.

The cost of the bike upgrades came to £65.95, giving me a pre-conversion bike cost of £215.94.

Before I even started converting the bike, I tested it out as a normal bike and rode it a bit to see how it handled and what things would need to be altered or changed, and also to get a feel for the bike in order to make some comparisons when riding unpowered with the motor fitted. That proved quite useful.

Choosing a battery

After reading OldTimer's review of a cheap Chinese LiFePo4 battery he had purchased from on eBay, I decided to take the plunge and order from the same supplier. At this stage I still had no clear idea how I would store the battery and controller. All I knew was, I wanted the battery as small and light as possible, but without sacrificing range too much. The reason for this was I decided I wanted a battery I could remove off the bike and carry.

The smallest battery the seller was offering was 10Ah..way too heavy at nearly 4kg. So I asked him would it be possible to make me two batteries, 5Ah each, with separate BMS and one charger. No problem he said. £174 all inclusive. Sold I said. The batteries arrived in about 7 days from China. They were cube shaped, 10x10x14cm, each weighing 1.83kg. This was about the maximum weight I could comfortably carry around, so I was confident I had struck the right balance between power and weight. I had done a bit of research into batteries on the forum and calculated that they should definitely be good for a minimum of 10 miles. But obviously I was still uncertain at this stage how these small batteries would perform in the real world.

Doing the conversion

The first thing I did was fit the front wheel with the motor and then I started thinking about where and how I would mount the controller and battery. The kit provided a little material controller bag with velcro straps which was pretty useless. Fixing anything to the seat post was quickly ruled out as the seat post didn't have sufficient height and clearance from the rear wheel for a battery and a controller. I had decided at this stage that it made sense to keep them both together, primarily for ease of removal and neatness.

One of my main reasons for doing a conversion was to end up with a bike that does not look like an electric bike. So I wanted the battery and electrics to be discrete and not noticeable.

It soon became apparent to me that the best place to put the controller and a battery, was on the handlebars. My thinking behind this was two-fold. Firstly, since the motor was in the front wheel, it made sense to have everything directly above it. Less wiring across the bike frame, and easy to remove stuff. Secondly, when I eventually get round to fitting a rear rack to the bike, I would want it kept free for carrying shopping and other things.

I found a cheap £5 handlebar bag on eBay which as luck would have it was the perfect size for my battery and controller. It is reinforced inside with plastic which was nice and attaches to the handlebars securely with velcro straps and had no problem supporting the weight. It looked discrete and it was neat.

I continued on with the conversion and fitted the throttle and LCD console. I opted for a thumb-throttle rather than a twist throttle, which as it turned out was a good choice and much simpler to fit.

After trying various places on the handlebar and a bit of fiddling around, it became apparent that the best place for both throttle and LCD, was together, on the left hand side. This not only looked better, but it was more comfortable position.



All that was left was the pedal sensor which fits into the crank and regulates the level of pedal assist power. This proved to be the most challenging part of the conversion so far, mainly because I didn't quite understand where to fit the sensor (my conversion kit manual was in German!) and how the crank assembly came apart. After getting some help in the forum I knew where the sensor had to be mounted and I did a bit of research into the crank assembly and figured it all out. Once I knew what to do the actual installing of the sensor went very smoothly as did re-assembling of the crank. And luckily for me, it worked first time. It was rather pleasing to turn the pedals on the upturned bike and hear the motor whir into action!

Unusually this kit has no brake cut-out levers. The controller is so efficient that it is able to cut out the motor instantly the second you stop pedalling. I had my doubts this would be the case, but was proved wrong as it did exactly what it said on the tin when tested. This I think is a big bonus as it saves the hassle of messing with brakes and means you can use whatever brake levers you like.

There were a lot of loose wires hanging around and I wanted a way to keep these out of sight and neat. Cable ties provided the solution. Using 3mm cable ties I was able to secure the sensor cable to the gear shift cable along the underside of the frame out of sight. The cable ties are so small you can hardly notice them.

So with the battery and controller mounted on the handlebar, and the LCD, throttle and pedal assist sensor all mounted, that completed the conversion work. The total weight of the bike with everything on it, comes to a little over 20kg. I would of liked it below 20kg but it's not too bad. I can carry the bike up and down the stairs folded without straining too much.

With the extra cost of the battery (excluding my spare battery) and charger, plus the handlebar bag coming in at £95, that brought the total cost of the project to £602.




 
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morphix

Esteemed Pedelecer
Oct 24, 2010
2,163
119
Worcestershire
www.cyclecharge.org.uk
My Conversion Project - Part 2



I've now begun making a few final improvements designed to enable the battery and controller to be removed from the bike easily and put back quickly. This includes converting the wiring to DIN connectors and converting the velcro straps on the handlebar bag to Gelert quick-release buckles. I've also sourced a plastic enclosure for the battery which I will pad out with foam inside, just to give it a bit of extra protection should it ever fall. The cost of these improvements comes to around £15.



Function and Performance

The kit itself performed very well. The LCD console makes a huge difference to the riding experience as it provides a lot of information you don't normally get on most electric bikes. As well as 7 levels of pedal assistance selectable from the LCD, there is a power assistance indicator showing you how much power the controller is giving, a battery life indicator, speedometer, journey time and distance covered reading. These are shown in km rather than miles, as the LCD is for the German market, but no big deal. The LCD also has varying levels of backlit which is very convenient for riding in low-light conditions or at night-time.



The motor is very quiet once you get going (a lot quieter than many other bikes I've seen) and is a good all-around performer. On the flat, it can deliver 15mph without any problem and with a bit of light pedalling the speed goes up to 20mph. Throttle-only seems a tad slower, about 12mph on the flat, and struggles a bit sometimes on hills. The motor on pedal assist however, coped well with nearly every hill I threw at it. Pedalling was not difficult even in the highest gear and the motor does not struggle to climb.

The battery exceeded all expectations and managed to provide 18 miles continuous power (at the highest pedal assist level power setting) on a single 2 hour trip before giving out.




Conclusion

Not only have I thoroughly enjoyed the whole process of doing the conversion, but I've learned a lot along the way, both about bikes and the electric side. I've saved at least £400 on what I was originally going to spend on a £1,000 ready-made bike (but in reality probably a lot more if I had bought a well known branded bike). I've ended up with a bike that meets all my requirements and most importantly, delivers where it matters, on performance.

I still have to sort out the gearing on the bike which is not quite there yet. This is more down to tailoring it to my own personal preference from road testing the bike. My own feeling is that a converted electric bike rides different to a normal bike. You shouldn't necessarily expect a converted bike to end up working exactly the same as it did unconverted, but with a motor on it. For one thing, your usage and gearing requirements may be quite different under power, and this is only something you can only establish when you actually start using the bike.

Stats:

Motor: 36V 250W Brushless
Battery: 36V 5Ah LiFePo4
Range: 18 miles (using Pedal Assist at highest level)
Throttle Only Top Speed: 12mph (without pedalling, on flat)
Pedal Assist Top Speed: 20mph (pedalling, on flat)
Motor weight: 2.3kg
Battery weight: 1.83kg
Converted Bike Weight: 21kg






 
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stevebills

Esteemed Pedelecer
Dec 14, 2010
443
4
Came from rftec in Austria.
I thought they were all from China or ebay and I am thinking of building something this year but not sure what
2 build I have a Gary Fisher hardtail and would love a 2500 watt hub on the back with a 60 volt lifepo4 22ah battery
and a 100 amp controller and I need to stop dreaming!:D
 
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morphix

Esteemed Pedelecer
Oct 24, 2010
2,163
119
Worcestershire
www.cyclecharge.org.uk
I thought they were all from China or ebay:D
Hehe nooo quality kit! Made in China still of course, but I reckon this kit is a cut above many of the kind you see on eBay cheaper..worth the extra money in my opinion... you can though I've noticed buy much of this stuff directly from China separately..it might work out cheaper that way but when you take into account the cost of import duty and VAT, plus the hefty shipping costs, maybe not. The good thing about buying from a European supplier who has close working relationship with the factory in China is they can provide proper support and shipping for parts is cheap from Europe.
 
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Spornofthedevil

Finding my (electric) wheels
Mar 18, 2011
19
0
Great build review, well done!

I'm currently considering doing the same to my Trek FX7.5, but am struggling to decide on a conversion kit an whether or not to change the bike and do it on a mountain bike with suspension.

I tested (and hired!) an Ultra Motor A2B today and love it, just think it's very expensive and a bit much when the battery runs out (it's 37kg).

I take it from your review that you'd recommend the process of building your own? Is there anything different you'd do regarding the motor and battery?
 

morphix

Esteemed Pedelecer
Oct 24, 2010
2,163
119
Worcestershire
www.cyclecharge.org.uk
Great build review, well done!

I'm currently considering doing the same to my Trek FX7.5, but am struggling to decide on a conversion kit an whether or not to change the bike and do it on a mountain bike with suspension.

I tested (and hired!) an Ultra Motor A2B today and love it, just think it's very expensive and a bit much when the battery runs out (it's 37kg).

I take it from your review that you'd recommend the process of building your own? Is there anything different you'd do regarding the motor and battery?
Thanks :) The UM A2B sounds like a hoot, but as you say damn expensive and not very practical as an everyday bike.

I would whole heartily recommend the self-build option over buying an off the shelf bike, purely because you can get something to your own requirements and save money into the bargain, if you're prepared to put in a bit of work.

Is there anything different I'd do about the motor and battery... I don't think there is you know. I'm really happy as far as the motor goes and battery really surprised me on the range.. I have no complaints at all about either.

I would however probably choose a different bike I think with hindsight, and probably would of gone for a smaller 20" wheel folder and lighter. I may build another one because it's so much fun and addictive tinkering around. Would probably go for a rear wheel motor too but purely for appearances sake.
 
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Oiseaux

Pedelecer
Jan 19, 2011
128
0
La roche Posay, Vienne, France
You have inspired to go out on a bike ride last week and convinced me to have a go with a conversion kit this week. I am a bit obsessed (it's in my nature) about noise and drag on front wheel hub motors. When I rode the bafang powered off the shelf bike the noise was very pronounced with motor on and when cycling with motor off the drag was very noticeable. When I rode the Giant twist with Sanyo motor I actually thought at first that the motor wasn't working because of the low level of noise and with motor off it felt as if there was no extra drag at all.

Which category would you put your Vitenso motor in.

Happy cycling,

Oiseaux
 
Hello,

"vintenso" is of course build in China but it is a good motor kit
In china you can buy good and bad. The "vintenso" namned kit from rftec is a good kit for converting a bike.
rftec is a serious and honest trader, it is a company i would reconmend.
Not the cheapest kit but good quality for a good price from a honest trader

regards
frank
 

morphix

Esteemed Pedelecer
Oct 24, 2010
2,163
119
Worcestershire
www.cyclecharge.org.uk
You have inspired to go out on a bike ride last week and convinced me to have a go with a conversion kit this week. I am a bit obsessed (it's in my nature) about noise and drag on front wheel hub motors. When I rode the bafang powered off the shelf bike the noise was very pronounced with motor on and when cycling with motor off the drag was very noticeable. When I rode the Giant twist with Sanyo motor I actually thought at first that the motor wasn't working because of the low level of noise and with motor off it felt as if there was no extra drag at all.

Which category would you put your Vitenso motor in.

Happy cycling,

Oiseaux
Hi Oiseaux,

Thanks for your comments :)

To be honest, I don't have much "hands-on" experience with other bikes as I had rode only one bike before I decided a self-build was the way for me...I did look at a lot of videos though of other bikes like Wisper and Ezee and looked at the noise they make.. The bike I tried out before ordering my kit was a Wisper copy-cat with a 250W (I think Bafung) motor..I found it noisier than the motor I have now... I must say the noise did bother me a bit as I didn't want to attract attention when riding.

But to answer your original question... I would say the motor with my kit is quieter than some bikes I've seen. When it gets going I can't hear it and sometimes I forget it is running. But when starting up/accelerating from a standing start (in higher power levels) it can be quite noisy.. it's also noisy when going slow in high power up hills.. I think this is common to many bikes though and is just a feature of electric motors.. I find you can reduce the amount of noise when starting by doing a gradual power increase or just by pedalling to start off.

The drag is not very noticeable at all, compared to the other bike (rear wheel motor) which was practically unrideable without power on. I can ride my bike no problem without power, the only problem I have is that I'm so used to riding it in highest gear on power (which seems like 2nd or 3rd gear!) that when the power is off, it's a shocker to pedal in top gear..I have to reduce gears right down and I move along a lot slower in those lower gears.. I'm wondering if my bike being a front wheel motor also helps minimise drag..


EDIT: I can't absolutely confirm the motor on that bike I tried was in fact Bafung, so don't let it put you off considering it as I know some people do highly rate those motors.. As I recall some people who saw pictures of my review of the bike at the time said it looked like Bafung possibly.
 
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morphix

Esteemed Pedelecer
Oct 24, 2010
2,163
119
Worcestershire
www.cyclecharge.org.uk
Hello,

"vintenso" is of course build in China but it is a good motor kit
In china you can buy good and bad. The "vintenso" namned kit from rftec is a good kit for converting a bike.
rftec is a serious and honest trader, it is a company i would reconmend.
Not the cheapest kit but good quality for a good price from a honest trader

regards
frank
I agree Frank.. You have to remember that rftec are Austrians and they speak very little English, all their instructions are in German..but it's not too difficult to work out from the diagrams and translate parts you need to... The guys who run rftec are helpful and dealt with my questions.

As Frank said, there's good and bad kits out there.. I think it's worth paying a bit extra for a quality kit that has a good controller with an LCD and the support of an established European company behind it. From what I understand, this controller or LCD were being used by Wisper and also the motor by Electric Wheels Company, although I can't confirm the latter.
 
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