The eBike thread

unkel wrote: »

That's the kind of info I need too, thank you! So all those electric scooters you see everywhere are also not road legal then? Why is nobody stopping them? Is it likely this legislation will be changed soon?

So if this kit had just a 250W motor it would be road legal, it seems to have the sensor that does what you describe?

Linky


I don't really want a bike that's not road legal, but how would a Garda know what wattage the motor is?

I don't particularly want or need a 1000W motor, but my battery has to be 48V and most 48V conversion kits seem to have motors of 500W and over...

A Guard can't know and will most likely not care unless you're not peddling......if you peddle or pretend to peddle there isn't a lot they can do but don't ride around making it obvious, it's a lot easier for me living in the country, I could do what I want but used caution in town, don't ride at 50 Km/h in cycle Cough Cough, I mean "BUS Lanes" and you'll be fine.

One of my first kits I built back in about 2010 used I would pretty much guarantee this exact motor you linked to.

I ended up hacking the controller and running about 5 Kw through it and boy did I have a hell of a time, the acceleration was mental !

Anyway the advice is avoid this motor, they are fine as throttle only setups on more level ground with some small hills but it's all Crank drive these days because crank drive is more efficient for hills, much more in fact.

The downside with these motor kits is they are not really designed for peddling without motor power and there can be some mad resistance when peddling without power.

The kit you linked to, that motor is an absolute B1tch to peddle without power, it's a direct drive motor and the motor magnets create a hell of a drag when no power is applied.

If you want a hub motor kit then the internally geared hub motors such as the MAC motors are one of the best, they have gearing for better toque and efficiency but they are noisier.

This is probably the best place to buy ebike kits, https://em3ev.com/ this guy is called Paul and is from the U.K living in china and has direct contact with the factory that makes the motors and is very well respected on endless-sphere.com

Paul also builds his own battery packs, I advise against building your own from old laptop packs , ebikes have vastly higher power requirements + different cells will have aged more than others and have different internal resistance and you need closely matched cells in a pack, believe me.

I used Hobbyking Lipo in the past and it's great, https://hobbyking.com/en_us/zippy-compact-6200mah-6s-40c-lipo-pack-xt90-1.html

LiPo is great as it can provide massive power from a tiny pack but it is volatile and can not be stored in the house ( absolutely can not be stored in the house )and needs to be charged on a RC balance charger, LifeP04 is safer, much safer but can't give out as high power and also needs RC balance charger, is heavier and bulkier than LiPo, once you know how to handle LiPo it's great and you can build a very cheap pack, the downside is that you need to buy an RC charger and power supply, so I recommend buying the pack from em3ev.

2 in series of the packs I linked to in hobbyking will give you 44 volts and another 2 in parallel will give you 10 ah and double the same for 20 ah of battery or 880 Watt hrs of storage.

The Mac motors are available in 8T windings, 10 and 12T, the 8T is good for level ground and some hills, 10 and especially 12 T are better for steep hills.

8 T will do 28 Mph on 44 volts, 10T probably 20 and 12 T probably 15 Mph.

They are geared hubs and really great for peddling without power because they got a clutch that disconnects the motor mechanically when no power is applied creating 0 motor drag.

Hub motors need torque arms at each wheel nut to prevent axle spin in the dropouts, if this happens under load it can be quite dangerous and break the wiring to the motor and it is a right pain in the ass to connect it all back up again and I'm speaking from experience..........Torque arms are essential.

If you got lots of hills then the Bafang BBS02 or BBSHD from em3ev will be the man for the job, motors are more efficient at higher RPM and the Crank drive motor can use the bikes gearing, a hub motor can not and so when on steep hills the hub motor "can" bog down and most of the power turns to heat and can kill a motor fast but I've climbed pretty steep hills on motor alone with the 8T mac motor @ 48 Volts and roughly 40 amps or 2 Kw pulled from the battery.

For slow steep trails the Crank drive is the best. I've got up Mount Leinster with a Bosch Crank drive @500 watts , but it was very tough and the gearing helps a lot. Some of this was 22% grades !

With motors Current gives you torque and voltage gives you speed.

And I repeat........1860 cells from various sources and different packs, different ages is a recipe for disaster and fire and a potential to burn the house down or block, 18650 need a BMS ( as with most lithium cells ) and to be correctly wired and correctly welded tabs with proper fused links, do not do it.

krissovo wrote: »

I bought a mid drive kit (bafang) from Green Bike kit with a 52v 14.5 ah samsung battery.
It’ was not compliant to EU rules in its raw state as its 500w and did nearly 50kmph at full pelt and would easily overtake mopeds. I have since limited it to a more reasonable 25kmph using the controller. Anything over speed 4 on the controller and my legs cannot keep the cadence to drive it.

The mid drive is really good as it drives the crank and not the wheel so its more natural feeling and also as it drives the gears I can literally ride up the side of a mountain without stressing the motor or battery and I am a big bloke.

Ships from Asia somewhere via Rotterdam so no import taxes and it also came with lights that are powered from the battery. I get can get similar range to some early Nissan leafs but 60 to 80k’s is normal with plenty of assist.

the bafang kit you mentioned is probably the BBS02 and more like 750 watts, they are good kits but they have the issue of resistance without motor power which I doubt is an issue for most as I expect they will ride with some power.

Even the Bosch ebikes are well known for resistance with no power, my 2013 has it and it's only very recently Bosch have addressed this issue.

One of the best are Brose motors but they are expensive, made in Berlin, the best ebike motors come from Deutschland and are unfortunately OEM motors.

One of the best bikes I built was an rear internally geared MAC 8T I got from em3ev.com. I lost 20 Kg with this kit believe it or not, over 3 months..... then I had 2 Children, started working shift and put it all back on and have no time for cycling any more and can't bring the lads out because Irish back roads are extremely dangerous and Ireland lacks proper cycle lanes.

Anyone into cycling should go to Deutschland, it's amazing......

Wtf ? wrote: »

After all your hard work.....https://www.dublinlive.ie/news/dublin-news/scooters-dublin-gardai-video-seized-16147126
Careful now....

Scooters are different, with ebikes all you got to do when in town or in dublin city is pedal and not cycle like an idiot and you'll be fine.

unkel wrote: »

Aye my thoughts too. I'm not interested at all though in the efficiency of the pack, nor its performance, nor its longevity. A perfectly managed LiFePo4 pack will easily last 50 years and tens of thousands of cycles in the Irish moderate climate and still have 70-80% capacity, but that is not something that I am aiming for

Just 100 cycles and poor capacity are fine with me. As long as things are safe...

No harm in trying but don't expect a lot just make sure you use fuseable links , one mistake and the whole lot can go up in smoke, again lithium fires are scary and they smoke like hell and you have to make sure if it does ignite that you can vent the smoke it's highly toxic and it's unlikely you can out the fire out with ease.

xckjoo wrote: »

I'm going to add some confusion by saying that I disagree with Mad_Lad and think hub motors are the way to go :pac:. I think a front hub motor will work for 99% of commuters. Simplest to install, no major maintenance and changes to the mechanics of the bike. Just make sure you include the torque arms and have a steel front fork (no suspension). They do make your bike heavy and you won't want to cycle it with no power, but once it's under way you don't notice. I'd say >70% of my commute is pedal powered due to the motor cutting out at 25kmph (road legal). The motor is mainly for getting me moving and taking the pain out of hills and wind. I haven't used a mid-drive, but I think they might only needed for "fancier" cycling like off-roading.



To get you started, I think this is what you need for a front hub conversion:

• Front hub motor and rim (buy them pre-spoked so you don't have to do it)
• Torque Arm
• Controller
• Battery pack (match power to hub motor) + charger
• Brakes with motor disconnect cable
• PAS (Peddle Assist Sensor) - Get one with the ring you can clip open to save yourself the nightmare that removing the bottom bracket can be
• Ebike computer (the little screen to see what's going on)

Wires and stuff should be included. I like to have a throttle too because my PAS is a bit hit-and-miss but I think this might not be technically road legal so keep that in mind

It depends on what you want to achieve, and what power you want, too much torque and the front forks can break.

Front or rear mounted motors, torque arms are essential.

Again, direct drive hubs are a b1tch to pedal with no power.

Crank drives are more efficient for hills, Hubs are great but they like power.

Front hubs are fine but can spin wheels in the wet and they are not suitable for higher power setups and I'd certainly never consider a front hub because I like a bit of power.

My Bosch bike is very efficient but it only provides 50 Nm of torque but unlike a bub this torque is available at a much broader range because I can use the bikes gearing. They're up to 75+ Nm now and the better bikes provide 120 Nm from the German motor manufacturers , but they're well above 250 watts which is only a continuous limit anyway the peak can run well beyond this.

The worst about legal ebikes is that they provide no assistance beyond 15.5 Mph or so which can be a right pain in a strong headwind but the limit can be removed.

Swings and roundabouts for all setups.

The crank drives are also neater to install because the controller is built in to the motor, less fiddling with wiring and trying to hide wires.

Also ebikes are a target for thieves. You can't buy an expensive enough lock.

At the end of the day I would love a Brose ebike system but they are very expensive, it's crank drive and has no resistance when peddling with no power.

I really miss my 8T Mac motor , it gave me lots of power and I could use the throttle to give my legs a rest if I got tired and no pedal resistance, you will always notice the extra weight but that's what the motor is for at the end of the day.

I also used slick tyres pumped to 90 PSI which makes a big difference.

unkel wrote: »

Or not make the battery myself, but use a pair of hoverboard batteries in parallel. Built in BMS, 3C discharge rating (that's more than I need to charge the car at 860W) and come with XC60 connectors installed. $58 for a 0.3kWh (8Ah) lithium pack, that's very cheap :eek:

Linky


Slight issue is that it is a 36V pack. I saw last night that there are 36V hub motors. That's not the issue. And my daughter has a kids electric scooter which I think is also 36V, so could use that charger. More complicated to find a 36V inverter that can power a 1kW AC appliance

Any ideas welcome...

That ebike kit will run at 36 volts no problem, it's top speed will be lower and less torque. But here's the thing, the controller will have a low voltage cut off for a 48V battery , you'd need the software and cable to adjust the low voltage cut off to make it work with a 36 V battery.

4 ah battery x 2 would be 8 x 3c = 24 amps so it should handle the motor kit but I feel the peak power would be more.

unkel wrote: »

Yeah I've decided I'm going to buy cheap already made up batteries (with BMS) like above. And I think I'll abandon the idea of the "petrol can" for the EV. I guess a single 36V 4Ah battery be good with a 500W motor?

My bike is a Raleigh, probably about 5-8 years old. Model AL6061 "aluminium tubeset airlite", so yes aluminium. Not sure if fork is aluminium too. And yes, I am a fairly big lad, just under 6'2 and about 100kg

I would avoid the front motor, rear hubs are harder to fit but still easy. Few mins job. Snapping forks crossing a busy road is something to avoid.....

The 36 volt battery won't work on the 48 V controller because of the low voltage cut off ( LVC ) , you'd want a 36 V controller. Most of my controllers could be set via software but you might not be able to get it or cable for this controller.

The battery you linked to would likely die fast, it would be 4 ah x the c rate of 3 which is 12 amps and this ebike kit would kill it fast, it's way too much. You have to also think of the peak power.

Lipo is your man for this kind of job, small battery , big power. Or buy a dedicated battery one that you can use on a higher quality kit in the future, ebiking is a lot of fun.

unkel wrote: »

I hear ya. Still in two minds about it though. Now I have abandoned the idea of the petrol can, I could go either

-24V and a tiny 250W motor. This not only would be very cheap, but I could also safely go for a FWD. Fully legal too. And I have a single east facing solar panel on my shed, not connected to my grid tie inverter. It's currently charging a couple of leisure batteries in series, so 24V too. Could charge the bike pack on this with solar for free in no time with my existing basic PWM solar charge controller

-On the other hand I could get a more powerful and versatile 48V battery (much more expensive) and go for a high power eBike. I would have to get a charger, which would not run on solar

Just think about what you want, cheap or good ? Buying a cheap kit and upgrading later is a waste of money and you'll likely have to sell the existing kit on ebay and that's a lot of hassle. Selling in Ireland will be difficult.

The first link you posted to will do the job but be a b1tch to pedal without power, get it in rear wheel setup, it won't be any more expensive. You will need to add a cassette to match the gearing on your bike.

It's a 48V controller so you need a 48V battery and one that can handle at least 25 amps of current. You should be able to find a 36 volt version on ebay handy enough.

Steer well away from unknown battery sources, em3ev builds his own and has a fantastic reputation in the DIY ebike community, check out endless-sphere.

The Mac 8T with 30 amp controller would do the job nicely, even 40 amps with 48V will be around 2 Kw and a lot of fun.

Or get the Bafang BBS02 or BBSHD crank drive, they are not very difficult to fit and you have tonnes of power for all terrain, put the bike in the boot of the car and take it to some trails, it will be a blast and it's a bike that can do anything.

The crank drive will be easier on the battery too as they are more efficient because they can use the bikes gearing.

The BBS HD can be set de-tuned to 25 amps or to the full 30 amps on em3ev when you buy it. I would go with the 30 amp, you don't have to use all the power.

You're talking around 1 K or more if customs get you, they never did get me from em3ev but then again that was several years ago.

You could spend 500 euro's on a kit that is not so good but the choice is yours, the BBSHD would be better than many electric bikes sold that cost thousands more.

Direct drive motors are an absolute pig to cycle without power.

Geared hubs can be got in front wheel format also. ( but I would not use more than 500 watts max )

Fitting a rear hub the first time tok me 20 mins max because I had to get the spacers aligned properly and really bend the frame to get it in, that was back in about 2009/10 they fit a lot better now depending on where you get the kit, Paul from em3ev gets his direct from the factory and deals with them directly. I had 0 issue fitting a mac 8t back in a bout 2011, I really miss that motor.

Next motor I got was a Golden Motor magic Pie II, built in controller, about 750 watts but it wasn't enough for me so I ripped the controller out and put in a 40 amp and boy did it fly haha. Those were the days, but due to it's size it was even worse to pedal without power.

The Golden motor kits are actually pretty decent, easy to fit and built in controller.

All the direct drive hubs, ( without internal gearing ) are designed for those who don't want to pedal or peddle very little, if the battery runs down you will have a very hard time peddling home so my advice is for anyone who likes efficiency or any form of peddling to avoid direct drives like the plague.

Also the crank drive motors are not actually designed solely for high power use, on the contrary , they are better for lower power because you can use the bikes gear and choose a lower gear when the motor starts to struggle.

Crank drives are harder on the chain , gears etc but all this is really a doddle to repair and if you don;t constantly hammer the throttle they will last a lot longer.