Electric Bike Conversion Kit or Electric Bike?

The brake levers are more important if you use pedal assist, I agree of no use at all with a throttle only. However there is a lag between stopping pedalling and power stopping so brake levers that cut the motor immediately may make all the difference between crashing and not, if you use pedal assist.

Front hub is easiest and cheapest unless you specifically need traction e.g. potentially for offroading, or for more than road-legal power.
 
miniyazz said:
The brake levers are more important if you use pedal assist, I agree of no use at all with a throttle only. However there is a lag between stopping pedalling and power stopping so brake levers that cut the motor immediately may make all the difference between crashing and not, if you use pedal assist.
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I've just been out with pedal assist enabled on the top assist and not one single problem stopping however I'm probably using different components than you.
 
My slow progress continues, battery pack assembled, waiting for BMS from China, didn't like the one I got. So got a much bigger amp rating one which has heat sinks on the MOSFETs. Hopefully another 4-6 weeks and it'll finally be running. Its only taken me what 7months?

21.5amp hour, in the end.

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Glaucus said:
My slow progress continues, battery pack assembled, waiting for BMS from China, didn't like the one I got. So got a much bigger amp rating one which has heat sinks on the MOSFETs. Hopefully another 4-6 weeks and it'll finally be running. Its only taken me what 7months?

21.5amp hour, in the end.

205tkbb.jpg
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Is that 36v or 48v? Seems huge for only 21Ah 36v?
 
Energize said:
Is that 36v or 48v? Seems huge for only 21Ah 36v?
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36v and would say its pretty standard size. that averages out at 2150mah per battery. if you brought brand new batteries at 3200mah then yeah you could get it a fair bit smaller 70 batteries rather than 100. but that would cost you a lot.
10s10p

its a rather large battery, most ebike batteries are like 11 or 14ah
 
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Glaucus said:
36v and would say its pretty standard size. that averages out at 2150mah per battery. if you brought brand new batteries at 3200mah then yeah you could get it a fair bit smaller 70 batteries rather than 100. but that would cost you a lot.
10s10p

its a rather large battery, most ebike batteries are like 11 or 14ah
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Maybe it's because of the lack of scale, what dimensions does it measure? My battery is 15Ah but it looks like it's 1/8 of the size of that in the picture!
 
Energize said:
Maybe it's because of the lack of scale, what dimensions does it measure? My battery is 15Ah but it looks like it's 1/8 of the size of that in the picture!
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it certainly wont be 1/8th the size.
bottom edge of pack in the photo is 200mm, long (left side) 280mm, then one cell think so just over 65mm

if you used the best cells you can get, 3400mah then at 15ah you could get it to 1/2 that size.

and if its a cheap Chinese battery, you probably wont have anything near 15ah, one reason I went self build.

Moses said:
How much does it cost to convert? Then how much are retail electric bikes?
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prices rage hugey depending what you want, from cheap Chinese kits to expensive usa made kits and the price of the battery varies massively. not much help. but expect to pay around 400+ for a kit and battery at the low end.
 
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Moses said:
How much does it cost to convert? Then how much are retail electric bikes?
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I wouldn't buy retail unless you're spending £2000, much better to buy a decent bike and convert.
I use the Cyclotricity kits because they might not be the cheapest but they are a doddle to fit and touch wiood, I've had no problems yet.
You could get away with:
Front wheel - around £150
Controller - around £70
Throttle - around £20
Battery - around £200

Not sure on those prices but not far off.
 
Glaucus said:
it certainly wont be 1/8th the size.
bottom edge of pack in the photo is 200mm, long (left side) 280mm, then one cell think so just over 65mm

if you used the best cells you can get, 3400mah then at 15ah you could get it to 1/2 that size.

and if its a cheap Chinese battery, you probably wont have anything near 15ah, one reason I went self build.
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Oh right, 20x28cm that seems about right. The picture just makes it look way bigger than it is. :p

Yeah my battery is using panasonic cells, to be fair a lot of cheap chinese bikes use samsung or panasonic cells.

How much did those cells cost?
 
£70 recycled laptop batteries. well actually that paid for over 200 cells. which some went in the bin and others I might make a battery bank out of.

edit actually far more than that.
got 45 laptop batteries for £50 which are between 4-9 cells each.
and another order of 10 for £15

give it another few years and you'll be able to buy brand new for that price.
around 30gwh of lithium ion cells made in 2015 and by 2020 between tesla gigafactory and two other companies in china(byd and catl), that should swell to 125gwh in 2020. so prices are going to be slashed.
 
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Just found this forum!

Hi all, Interested in this discussion - as have just finished my fourth ebike conversion.
Bought my first purpose made ebike after a serious accident, a BH Neo City, was well impressed, kept me sane during recovery.
Already had two Thorn Raven tours, so, decided to look at converting these as a project (missus having trouble keeping up with me )
Decided on Cyclotricity front wheel kits, these worked, and are still working well.
Then moved on, looking for more comfort, side effects of accident not good. Tried a full suss mtb and decided that was the way to go. Bought a couple of Giant Stances, recommended as good basic bikes.
Fitted further Cyclotricity kits, this time 500w rear wheel kits, again very impressed, had to do a bit of modification, but, no real problems.
Now decided that we have reached the perfect set up, very comfortable, good range and great assistance. All round fun bikes
To the reason I decide to post! I would very highly recommend our final combo to the poster who asked about converting a mountain bike. Also interested in the pros and cons of building your own batteries, sounds interesting, but, is the cost worth it compared with purpose made?
 
I have a spare 500w Cyclotricity rear wheel that I took off after a month and converted it back to a front 250w.
I didn't like the idea of being able to do 24mph on the throttle (yes I know I didn't have to do it) and it scared me a bit even though I can pedal at that speed on the flat.
Twice I'd ran out of juice before a big hill and the bike was not fun to ride up with the weight of that wheel so that made me go back to the lighter front wheel.
I now have a Trek 4300 and Trek 7.5FX with Cyclotricity 250w fronts plus a normal Forme road bike which is way lighter than the other two bikes and feels like cheating.
 
Glaucus said:
36v and would say its pretty standard size. that averages out at 2150mah per battery. if you brought brand new batteries at 3200mah then yeah you could get it a fair bit smaller 70 batteries rather than 100. but that would cost you a lot.
10s10p

its a rather large battery, most ebike batteries are like 11 or 14ah
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Have you tested each cell for capacity, self discharge and impedance? Must have taken you ages.

I've just got a 52v14ah pack from Luna Cycles that cost £400 inc del. Weighs 3.1kg and measures 36cm x 9cm x 9cm. Such a good battery that it's now made my 1.2kw of lipo packs redundant.

SexyGreyFox said:
I didn't like the idea of being able to do 24mph on the throttle (yes I know I didn't have to do it) and it scared me a bit even though I can pedal at that speed on the flat.
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Haha, I put a 2.5kw from MAC motor on my Trek FX and it could do 45mph on the throttle. It didn't stay on the bike long, but it was a fun experiment - wheel spinning from a standstill up to 20mph was interesting!

IMAG03911_zps2fa04726.jpg
 
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amigafan2003 said:
Have you tested each cell for capacity, self discharge and impedance? Must have taken you ages.

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Yep and yep long time, not as long as I'm staging it out though.
And nice bike.

I would like a 1930s ish Peugeot vintage motorbike then put an 8kw rear motor in it, I think that would be cool for around city driving.
 
Edit:-

On second thoughts, linking to a sale thread on Pedelecs is probably classed as selling outside the MM.
 
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