UK newbie needs advice on 1st Ebike Build.

Hello Again,

Just been re-reading some of your replies and have a few questions (please don't laugh I told you I was new to all of this),

What does high discharge mean on the battery( Dev8h said it had to be high discharge when talking about bottle type batteries)?

I think CST means cassette, When talking about Bafang cst, Are there any other makes that take a proper cassette (splined) or are most the screw on ones?

What is the opinion on the Magic Pie 3 1000 48v kit? On ebay UK for £899, Is that a good price for the full kit inc 48v12AH Lipo battery and built in controller?

The choice of kits available are unbelievable so I need all opinions available please.

Thanks J.
 
High discharge rate means able to give high current for its size. Some of the cheaper bottle batteries can only give 1C, which means an 8.8 aH one can give 8.8 amps continuous, which is hardly enough for a 250w motor. They can give double that for a short time, but the chemistry in the battery can't work that fast, so the voltage starts to drop (voltage sag), and if you drive the battery too hard, you can shorten its life. The latest ones with Samsung and Panasonic cells can do nearly 3C, so the same size battery can give 20 amps continuous and as high as 40 amps for short bursts, so they can be used for 350w and 500 motors and controllers.

There are a few other Cassette motors. Bafang, MXUS and Xofo all make a 500w CST motor that share the same casings, so look identical. MXUS make a smaller 350w one and, even smaller still, there's the Q140 type. There's a few others that are a lot more expensive.
 
Thank you for clarifying that for me, so the bottle battery that you listed on my shopping list would be ideal for my needs then (36v 11ah).
So if I was to pair that battery to a 500 watt cst motor on my boardman hybrid, would I be able to keep the 10 speed gearing that's on it?
Maybe I could have the shifter altered to work with a 9 speed cassette if a 10 will not fit?

What sort of speeds would be achievable if I put some pedal effort into the equation ?
Thanks again J.
 
I think that that bottle battery should be OK with the S12S controller (23 amps), but the KU123 and S12P might be a bit to high on current. I haven't tried one of these batteries, but they fit them to some OEM bkes with CST motors.

10 speed gears should fit without modification.

The Bafang 500w CST motor is 270 rpm, so with 36v battery and 700c wheel would give a no-load speed of 24 mph, so about 22 mph on the road. You could get another 3 to 4 mph if you used the three speed switch on the KU93 controller. I use a CST at 36v in a 26" wheel and a KU123 controller with the three speed switch enabled. I get an easy 22 mph, and about 24mph with medium pedalling.
 
Hi all,
Excuse my lack of knowledge please but is it possible (if they would fit as I have 2 sets of bottle bosses on my bike) to fit 2 bottle batteries and link them together to get more power?
Or doesn't it work like that??
If it is possible what would I need to be able to do this?
Thanks in advance and apologies if this is a stupid thing to ask lol.
 
:oops: I take it from getting no responses that my question was a ridiculous one lol.
This is all so confusing to me, so I really do need all the help I can get.
Thank you d8veh for all your help so far and after thinking about it your shopping list seems ideal for what I want really but it's just the battery scenario I'm unsure of now.
Thanks J.
 
hi

sorry missed you post at first

yes you can parallel them together like that, in fact I'd recommend it as a minimum for what you want to build

trick is to charger them both up before you connect them together (so they're the same voltage) then connect them up and leave them connected... it's not a big deal with those kind of low capacity batteries, but it's worth doing it right :)

(if they were high capacity batteries and you connected them while one was empty and one was full, the fill one would discharge into the empty one (charging it up) very quickly and could do some damage :)
 
Can two bottle batteries really fit in your triangle? most of them pull upwards from their retainer, so you need more space than their actual size. Ifthis one were1mm longer, you wouldn't be able to get it out. you can see that there's no room in this triangle for s second one, but I'd need exact sizes of your frame to judge yours..

 
knighty said:
UK here too (Sunderland)

just wanted to say I do 40mph everywhere on one of my bikes and no-one every bothers me :)

I got a 1000watt 48v kit on ebay, a 72v 10ah battery from bms battery, and then a 72 controller on ebay

how good are you with electrics ? - it could well be worth buying yourself some cells/bms (battery management system) and connecting it up yourself, that way you fit them to whatever shape you want

I don't have a lot of faith in those bottle batteries at all :-o
Click to expand...

Hi there makkum! I'm about 20 miles North of you.

There's not so many police on patrol now, and I think they have better things to do than bother with bikes. Still. it's better keeping speed down when they are around. The thing I have to watch out for (and I can only do about 28 on the flat) are cars, other bikes, pedestrians looking at you then pulling/walking out in front of me because I'm only a bike and they only looked once so don't get an estimate of speed. I do mainly short journeys and the average speed is just a little over 15mph. And the roadworks are about to start again....
 
hiya!

yeah I agree, the biggest danger is people pulling/walking out in front of you

I normally keep the speed down, but it's nice being able to keep up with traffic etc.. or accelerate and get out of the way...

much safer doing 40 with the traffic than doing 30 and having people pass you tbh :)
 
I've had a long running problem where the bike would only start slowly, and speed picked up over a couple of miles so didn't want to use 72V, I just kept it at 36V - sometimes it suddenly kicked in at full power so I didn't want to risk it. I think I've solved it now so I can put my two 36V in series (bad original Crystalyte wire on one of the hall phases). I don't think I can honestly say I won't be using the extra speed at times :wink:
 
knighty said:
hiya!

yeah I agree, the biggest danger is people pulling/walking out in front of you

I normally keep the speed down, but it's nice being able to keep up with traffic etc.. or accelerate and get out of the way...

much safer doing 40 with the traffic than doing 30 and having people pass you tbh :)
Click to expand...

I have someone pull out on me every 20 miles or so. Perhaps more often. Sometimes junction after junction. On my last ride I was heading to a traffic island, watching the stream of traffic coming in from the next exit, traffic that should give way to me, just wondering which one was going to hit me. Sure enough, It was a bird in a probe that got her whole car out in front of me before realising she had nowhere to go. Again, I just rode round them without giving it any more thought. I was approaching at 20mph without assistance.

In the uk we have low bike usage and a high fatality rate. The dutch have 30 times more cyclists and a third of the fatalities. This is not a good place for going quick. Cars will insist on passing you, even if you are doing 30mph in a 30 zone. It is just instinctive. They will be convinced they can do so before a pedestrian central reservation. Before they know it there doing 40mph in a 30 zone heading towards the reservation convinced they should be passed you as they put you up the curb cutting back across. There is no safe speed to travel along with traffic. A speed they expect you to be doing is safest.


My cst goes a few mph faster than d8veh's through using a higher voltage. 12s 44.4v. Just 15amps though from a ku63. Mine would not go faster with higher currant as it only wants 14.7 amps at full speed. Around 26mph with light pedaling. GPS varified. Higher currant would only help me reach top speed faster.
 
Hi All,
Thanks for sharing your experiences with me and highlighting any possible dangers i'm going to encounter on my travels.

I have experienced many of the scenario's mentioned in the above replies so i am aware of how Stupid other road users are and taking all this on board i don't think a 30mph + machine is probably the safest thing to build.

I commute in rush hour traffic some of the time where those sort of speeds aren't possible any way due to the volume of traffic on the roads, So taking that in to account i'm definately going down the slower but more stealthy aproach.

I went to the Bike show at the NEC over the weekend and had my first ever go on an Ebike, All be it a limited 250w 15.5mph one, But i must say i came back with a massive grin on my face thinking of what a slightly faster/ more powerful one will be like...I'm hooked :D :D .

My commute will be so easy on one of these and if i'm not feeling very energetic i'll let the motor do most of the hill climbing lol, Should hopefully cut my journey time down from 28 mins to low 20's ( possibly).

The bikes i tried at the show were pedal assist, is this something i should go for? any opinions on the benefits of this over a throttle/thumbshifter type system?

Thanks again Jay.
 
A throttle is very handy in a lot of situations. Pedal assist is better once you get going. I noticed at the show that throttles are starting to become a rarity. I think that the UK companies are gradually preparing for full EN15194 compliance. Are you going to build your own bike or buy a ready-made?
 
Hi,

I was asking about throttle types because I noticed that at the show the bikes I took out didn't have throttles, They were pedal assist only.
Is it easier to build a bike with a throttle/thumb shifter or one with the pedal sensor or do I need both? ( I don't have a clue and this will be my first attempt at creating a Ebike).

I'm going to be using the mountain bike I've just bought ( GT Agressor Xcr) as the base for my build, It's a 26" wheel model with hydraulic disc brakes and a 140mm suspension fork with lock-out.

D8veh, you made a list of parts for a build on the 1st page of this post, Does that and the speeds achievable only apply to a 700c wheel?
If so what would I need to get into the mid 20's mph on a 26" wheel build??

If any one on here has any recommendations for a parts list for my build ( inc where to get them from) I would be very grateful, I know different people like different makes and suppliers so on, so it should be interesting to see what ideas are thrown into the mix ( If any one actually does lol).

Ideally i'd like it to look fairly stealthy ( some thing like what Nader on here builds ) but if that's not possible due to my speed requirements as small and discreet as possible please.

Thanks in advance J.
 
Hi Again,

Can anyone tell me if this item 181216043604 on Ebay (uk) would be any good please?
I don't really understand what it is I should be looking for on the spec's sheet but its rated at 20 A continuous discharge and 40A max and is the price ok for what it is?

Thanks J.
 
loxster said:
Hi Again,
Can anyone tell me if this item 181216043604 on Ebay (uk) would be any good please?
I don't really understand what it is I should be looking for on the spec's sheet but its rated at 20 A continuous discharge and 40A max and is the price ok for what it is?
Thanks J.
Click to expand...

it's hard to tell because the cells inside are unknown... so they could be great, or crap, or somewhere in-between... probably somewhere in-between

this place is cheaper for a simmiler battery...
http://www.bmsbattery.com/36v/571-bottle-ebike-battery.html

make sure you pay through paypal, because there service has a reputation for being a bit crap... but I've ordered from them 6 times without any problems :)



also.. for people pulling out infront of you... fit a crazy bright front light... I have one of these
http://www.ebay.co.uk/itm/18w-36V-48V-led-head-light-super-white-electric-motorcycle-e-bike-motor-12-90v-/390569930300?_trksid=p2047675.l2557&ssPageName=STRK%3AMEWNX%3AIT&nma=true&si=6fmDg6ivOQd3Wa7Xja3sEa5V9Io%253D&orig_cvip=true&rt=nc

it's crazy bright... so much so that I've got it pointing right down so the focal point is about two foot in front of the bike but it still sents plenty of light out ahead.. makes you stand out a bit and from a distance people arn;t sure if you're a pedal bike or a motorbike (I guess) and they give you more room (deffo. more room)
 
Thank you Andrenoites for the link to your build, I would really like to go the hub motor route/ Bottle battery if possible as it still looks like a bike to the un-trained eye :wink:

It's looking like a 500 watt cst hub motor, Controller and 36v 12 a Bottle battery at the moment unless some of you wise people on here can recommend me some thing better.??

If it was your £700 what would you do????

Is it possible to but my own 36 hole rim ( A better/stronger one than the std one supplied) and have it laced up to the motor??
If so can any one recommend a good wheel builder to me and a few ideas on good strong rims.
Looked for 36 hole Mavic rims or some thing of that quality but they are hard to find.

Thanks J.
 
I like riding with pedal assist. It saves me having to operate something else. Preserving some of the cycling experience. Throttles can be fitted too, but there is a 6.5 kmh limit. They are for walking the bike around. So having one won't look out of place, although I can't imagine your going to have the limiter in place.

I couldn't see a 12ah bottle on bms. Will it support at least 15 amps? Even that is half what a cst could take if ridden appropriately. Any less than 15 amps from the battery and you would have to stay in legal mode. 15 amp is just enough for the little 6 fet controller to be used unlocked. You would want to know there was headroom to mod the controller really though. Under 15 amps the cst might not be worth having. D8veh might hook you up with a smaller cassette carrying motor, saving about 1.5kg if you do stick with such power levels.
 
Thanks for the advice on bottle battery compatibility!
I thought that the one I put a link to could run 20a continuos? Isn't that good enough?
Can anybody tell me if I can buy my own 36 hole rims and have it laced to the motor?
This way I can get a good quality make ie mavic etc or does it have to be Ebike specific?
Thanks again J.
 
loxster said:
Thanks for the advice on bottle battery compatibility!
I thought that the one I put a link to could run 20a continuos? Isn't that good enough?
Can anybody tell me if I can buy my own 36 hole rims and have it laced to the motor?
This way I can get a good quality make ie mavic etc or does it have to be Ebike specific?
Thanks again J.
Click to expand...
Yes. Of course you can.
 
Hi,

Can anyone recommend me a quality 36 hole rim to have a motor laced up to?

Am i right in thinking some thing along the lines of a good quality down hill rim ( mountain bike) would be needed for the weight etc of the motor?

Like i've said previously, I have no idea what is needed to build my E-bike :roll:

Thanks J.
 
On all my bikes, I use cheap Chinese double-walled rims. I've never had a\problem apart from the occasional need to re-tighten a few spokes after settling in.
 
Hi,

I've made the mistake of reading through a lot of posts on here and searching the Net looking at different vendors and I've realised that going the bottle battery/small hub motor is not going to do it for me long term.

The Gt I've bought should hold up to some mild abuse on the local single track and bike parks near me so I've decided this is the route I intend to go ( Thanks to everyone who have helped so far with ideas and tips ) .

Reading some of the posts it seems a Mac 10T from Em3ev and one of his 50v triangle batteries will do the trick, can anybody foresee any problems with this set up? Or recommend any other set up?

Would this set up achieve mid 20's mph and 16-20 mile range with me pedalling?

Thanks again J.
 
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