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The eBike thread

unkel

A quick look seems that this doesn't really seem to fit in the cycling forum. So starting a thread here about all things eBike

I'll get the ball rolling. I have zero experience with eBikes. But I was going to build myself a battery anyway, for various reasons (like in bringing with me in my EV as a "petrol can")

I'm going to buy a solderless kit to make the battery (with 18650 cells I have removed from dead / old laptop batteries). This kit cah handle 20A max, and I would like the battery pack to produce 1kW constant. P=V*I so 1000W = 50V * 20A

This dictates that my battery needs to be nominal 48V (was thinking of making a 24V battery pack, but that won't be able to charge my car)

A quick browse on eBay and Amazon shows that you could buy a powerful 1000W bike conversion kit with everything needed except the battery for about GBP120 (a bit more from Amazon but peace of mind)

What to buy though, front wheel or rear wheel kit? Pros and cons? Any other advice?

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[Deleted User]

unkel wrote: »

I love the torque of the mid drive. That will be impossible to beat with any other setup. And I haven't even gone BBSHD + small chain ring yet. It shouldn't surprise me really, instant torque has always been the most important feature of my cars too. That's why I used to have normally breathing large V8 petrol auto saloons (and I hate the near zero torque of small engined modern cars at idle and their turbo lag). And when these big engined cars were no longer around as a viable family car option, I switched to a fully electric car.

I know the drawbacks, I don't yet know how bad they will be for me. I will go Lekkie chain ring, which seems made to grip the chain much better. I have already ordered a gear sensor (which I might, or might not fit). I won't mind fitting a better chain and I guess I will have to live with a lot of wear on the cassette.

The BBS motors have an IP rating of 65, which means they can stand jets of water sprayed at them, but not being submerged for lengths of time. I guess the occasional dip into a deep muddy puddle should not be a problem

My biggest problem now is to offload my surplus to requirements bikes and start looking for the ultimate bike and then get the appropriate BBSHD kit for it!

It's a shame you never ran real power through a HUB it's mental fun but those torque arms become ultra important.

Nice build Unkle !

It's a shame you didn't get to build a high power Hub, you can't beat a Direct Drive hub motor for sheer raw smooth power running 5 Kw or more peak with no interruption of power for gear changes etc.

Even a 8T mac at 3.5 Kw is amazing.

The Mid drive would be more efficient for Hills and slow hilly trails but you can add a scooter motor that would do anything but it would be a lot heavier.

unkel

Direct drive is out as I want to cycle myself too if I want. Also the torque from stand still (even from a 5kW direct drive) is far lower than a 1.5kW BBS02 in a low gear isn't it? From a quick google it seems direct drive hub motors often don't even make half the torque that their spec sheet claims.

Direct drive are king for top speed. But I've not much interest in anything above 35km/h really...

[Deleted User]

unkel wrote: »

Direct drive is out as I want to cycle myself too if I want. Also the torque from stand still (even from a 5kW direct drive) is far lower than a 1.5kW BBS02 in a low gear isn't it? From a quick google it seems direct drive hub motors often don't even make half the torque that their spec sheet claims.

Direct drive are king for top speed. But I've not much interest in anything above 35km/h really...

Power is power and feeding a Hub lots of amps, will blow any BBSHD out of the water, especially considering the uninterrupted constant smooth power with no need to change gears.

Getting the spec of the Hub right is important. The relatively small power requirements of the BBS02 and BBSHD mean they are smaller and lighter for their power delivery and have the advantage of the bikes gearing for better efficiency for the slow hilly stuff.

The only real disadvantage of a hub is that they can't use the bikes gearing so can't provide max torque in every circumstances.

A hub has max torque at 0 rpm and tapers off the faster it spins.

My Mac 8T could do everything I needed and climb 12% hills at 50 Km/hr at 52 volts no problem @ around 2 Kw. The only place I would not have taken it would be Mount Leinster and I regret not doing it after. The little 50 nm Bosch climbed the 20-24% grades but it was tough as hell and it only did it because of the 3 speed sram gear hub which I messed up by the way and can't get parts because Sram don't make gear hubs any more because most bike manufacturers are using these newer massive cassettes with something like 10 speeds so gear hubs are being seen less and less as well as the traditional 3 speed front chain rings.

I damaged the clutch in the MAC 8T after simply because I had the torque turned up way too much in the controller and it was hammering it from a standstill, if I had to limit the torque at start off it would have been a lot easier on it, today it comes with the upgraded much heavier duty clutch if you buy the "upgraded" version. But the gears and stator were perfect even after all the abuse I had given it. I do miss that motor.

unkel

Deleted User wrote: »

Power is power and feeding a Hub lots of amps, will blow any BBSHD out of the water, especially considering the uninterrupted constant smooth power with no need to change gears.

Are you saying a 5kW direct drive hub motor will be quicker at accelerating from 0-20km/h up a 20% incline than a BBS running at 1.8kW (58.8V * 30A) with zero human effort in either case?

Any link to where I could buy such a 5kW motor? I've seen links for 3kW motors alright, but these typically do not get their full power unless you feed them with 96V. And there's no way one of those will out accelerate a BBS at even 58.8V

loughside

unkel wrote: »

Are you saying a 5kW direct drive hub motor will be quicker at accelerating from 0-20km/h up a 20% incline than a BBS running at 1.8kW (58.8V * 30A) with zero human effort in either case?

Any link to where I could buy such a 5kW motor? I've seen links for 3kW motors alright, but these typically do not get their full power unless you feed them with 96V. And there's no way one of those will out accelerate a BBS at even 58.8V

I think you`ll find the HD will be quick enough

https://www.youtube.com/watch?v=RbiNoNmqUpg

put on a 52 T if you want more :cool:

John Hutton

unkel wrote: »

I love the torque of the mid drive. That will be impossible to beat with any other setup. And I haven't even gone BBSHD + small chain ring yet. It shouldn't surprise me really, instant torque has always been the most important feature of my cars too. That's why I used to have normally breathing large V8 petrol auto saloons (and I hate the near zero torque of small engined modern cars at idle and their turbo lag). And when these big engined cars were no longer around as a viable family car option, I switched to a fully electric car.

I know the drawbacks, I don't yet know how bad they will be for me. I will go Lekkie chain ring, which seems made to grip the chain much better. I have already ordered a gear sensor (which I might, or might not fit). I won't mind fitting a better chain and I guess I will have to live with a lot of wear on the cassette.

The BBS motors have an IP rating of 65, which means they can stand jets of water sprayed at them, but not being submerged for lengths of time. I guess the occasional dip into a deep muddy puddle should not be a problem

My biggest problem now is to offload my surplus to requirements bikes and start looking for the ultimate bike and then get the appropriate BBSHD kit for it!

I have the gear sensor and haven't bothered with it. With the pedal assist I haven't needed to cut the motor mostly and the odd time I need to shift under heavy load I slightly pull the break lever which cuts out the motor and I change then, same as the gear sensor really but it's one less thing to fit AND this way I decide when to cut the motor and I don't have the annoyance of it cutting out under low load when the gear can change perfectly without damaging the chainset.

Would be interested to see what the lecky chainring is like

unkel

loughside wrote: »

I think you`ll find the HD will be quick enough

https://www.youtube.com/watch?v=RbiNoNmqUpg

put on a 52 T if you want more :cool:

You haven't been paying much attention to my priorities

I want torque. I don't care about top speed. If it was top speed I wanted, I'd have no business with a mid drive kit...

SCOL

unkel wrote: »

You haven't been paying much attention to my priorities

I want torque. I don't care about top speed. If it was top speed I wanted, I'd have no business with a mid drive kit...

I'm looking for "top Speed" so should I be looking at a rear wheel kit ? I was looking at a mid drive.

As I said on before my problem is I know nothing about electrics.

unkel

For very high top speeds, you'd be looking at a direct drive motor (can be front or rear wheel). A 1500W rated 48V direct drive motor, fed with 96V will produce 3kW, probably good for at least 80km/h :pac:

SCOL

unkel wrote: »

For very high top speeds, you'd be looking at a direct drive motor (can be front or rear wheel). A 1500W rated 48V direct drive motor, fed with 96V will produce 3kW, probably good for at least 80km/h :pac:

Will a 48V motor take 96V ?

I was going to buy those batteries off Ali Express that you said a while back. I also need to get a battery charger.

[Deleted User]

unkel wrote: »

Are you saying a 5kW direct drive hub motor will be quicker at accelerating from 0-20km/h up a 20% incline than a BBS running at 1.8kW (58.8V * 30A) with zero human effort in either case?

Any link to where I could buy such a 5kW motor? I've seen links for 3kW motors alright, but these typically do not get their full power unless you feed them with 96V. And there's no way one of those will out accelerate a BBS at even 58.8V

Depends, it would be tough enough to start either motor without doing wheelies @20% grade.

that's if of course you're talking about starting at 20%.

You don't need a 5Kw motor but of course one rated for continuous 5 Kw would help due to heat lol.

I was running 5 Kw through 1 Kw hubs though admittedly not at 20% but close.

I did run the magic pi at 3 Kw at 20+ % grades but that wasn't a motor for the job in reality.

You could also run a 16 inch wheel for more torque and easier on the hub.

You need more experience with high power hubs, the BBS02 is naturally going to feel like a rocket compared to your earlier builds.

By the way, any plans to upgrade the brakes on your bike ?

John Hutton

Going over 40 on a push bike is asking for trouble, only safe, imo, if you are in the drops going downhill on a good road.

In any other circumstances you need great brakes and should really be wearing motorbike helmet and gear if you're gonna go 50 or 60 regularly!

SCOL

I have a 66cc 2 Stroke on a bike keep it at around 40 / 45Km per Hour and I have thousands of miles put up on it
I do use the engine to slow the bike down and no problems with breaking but I understand that doesn't happen with
an electric engine.

I'm hoping to use a Trek Hybrid with 29 Inch wheels for my "upgrade to electric" it has standard break pads on the bike
probably go for the mid drive as I don't want to buy another bike. If the breaks are a Issue I'd change the kit over to another
bike something 2nd hand with discs.

I'm going to use this for commuting. Start off on the peddle setting and build up speed I'm not looking for good takeoff speed
but I want it to cruise over 50Km per Hour at full throttle for about 10 miles.

[Deleted User]

SCOL wrote: »

I'm looking for "top Speed" so should I be looking at a rear wheel kit ? I was looking at a mid drive.

As I said on before my problem is I know nothing about electrics.

What speed are you looking for ? and how fast do you want to get there ? and do you want speed on hills ? what size hills etc ?

Most important will be your bikes brakes, if you're not prepared to upgrade then you should forget about it. You're talking about needing 8 inch disks front and rear along with hydraulic brakes.

Direct drive hub motors are very reliable and need no maintenance but are hard to pedal without power to the motor.

Geared hubs provide more torque and need a little more maintenance but probably not for a few years. But it's no harm to open it, clean all the grease out and apply new grease.

Getting speed is easy but you'll use a lot more battery energy depending how fast you intend going.

[Deleted User]

SCOL wrote: »

I have a 66cc 2 Stroke on a bike keep it at around 40 / 45Km per Hour and I have thousands of miles put up on it
I do use the engine to slow the bike down and no problems with breaking but I understand that doesn't happen with
an electric engine.

Yes, some electric bikes can use regen to brake but usually this is limited by the amount of current the BMS + battery can take unless of course your run LiPo and have no BMS and LiPo can take much higher charge current than most Li batteries.

liamog

SCOL wrote: »

I'm going to use this for commuting. Start off on the peddle setting and build up speed I'm not looking for good takeoff speed
but I want it to cruise over 50Km per Hour at full throttle for about 10 miles.

Mod Note: Please be aware that any discussion of modifications to an e-bike must stay within legal limits as per standard boards.ie policy

[Deleted User]

There's nothing illegal about buying or building/modding an off-roading ebike that does not need to comply with the road traffic act.

If there is then close the thread.

SlowBlowin

Deleted User wrote: »

There's nothing illegal about buying or building/modding an off-roading ebike that does not need to comply with the road traffic act.

If there is then close the thread.

Its obviously a very touchy subject, and as the poster mentioned using it for a commute I was not surprised a warning followed.

I only use my high power ebike on private roads, so hopefully this thread will remain, although I share your frustration as there are numerous threads on fast car tuning and fast (illegal) motorbike riding all of which seem to comply with the same policy.

I think the controller has gone on my bike, the original one showed a max of about 1200 watts at full power (52v), can you recommend a modern replacement ? I guess I would go for a new screen and throttle too, would it be best to replace the pedal sensor at the same time ?

[Deleted User]

Oh right, never noticed the "commute"

Well, I was talking about Mount Leinster which is a private road so that gets me off the hook

[Deleted User]

SlowBlowin wrote: »

I think the controller has gone on my bike, the original one showed a max of about 1200 watts at full power (52v), can you recommend a modern replacement ? I guess I would go for a new screen and throttle too, would it be best to replace the pedal sensor at the same time ?

You could get a Lyenn controller. I got one from him before and it was great, should be programmable too so email him if you got questions.

http://www.lyen.com/ Expensive yes, but good.

Or try ebay.

I got no experience with pedal assist systems on DIY ebikes so can't recommend anything.

You could also try em3ev.com also good controllers and programmable so you can make it road legal too when you want to take it on the road.

I must admit though, I'm well out of experience with DIY kits these days. It's years since I built an ebike.

SCOL

I did say commute but It's all on private roads, just to make that clear.

SCOL

https://www.ebay.co.uk/itm/EU-NO-taxes-48V-750W-8fun-bafang-motor-BBS02B-crank-Motor-electric-ebike-kits/253794681242?var=553275505340

I've ordered the same do I need to order the sensors as they don't come with the kit ? or do I really need them ?

unkel

I ordered one as it was not much more than a tenner including delivery (still haven't got it). You don't really need it as John Hutton has explained. I might fit mine at some stage just to see what it's like. Or I might not

unkel

It's a good seller BTW. When I bought mine it read like it included the light and the sensor. And when I contacted them they were quick enough to reply explaining that was a mistake. I then suggested they change their ad and they literally copied and pasted my suggestion

"(includes connector for 6V light and connector for Gear/Shift sensor. Light and sensor do not come with this kit and have to be bought separately)"

Copyright: unkel!

SCOL

Now to order the batteries and a charger.

Am I right in saying that the controller is built into the motor ?

unkel

Yep. All click and play. Very easy setup provided fitting the motor itself into your bottom bracket isn't causing issues.

SCOL

I bought the Kit yesterday, so now I need a battery and a charger.

what's my best option ?

John Hutton

SCOL wrote: »

I bought the Kit yesterday, so now I need a battery and a charger.

what's my best option ?

I got a battery, with charger, from PSW power too, they have a website

unkel

There's different options. PSW Power is a very decent supplier, if you want an all in one solution, go with them. Unlikely you get a better price elsewhere for a similar pack. Their BBS02 motor kit was also the cheapest I could find. And shipped from within the EU, so no customs implications

If you don't have the budget for that, you will have to cut corners like I did and buy some very cheap overstock scooter / hoverboard batteries and connect them in series / parallel. Or build your own battery from dead laptop battery packs or other 18650 cells you source yourself. There is a learning curve here. This is not for everyone.

To update my own situation: I got the new nylon gears, degreaser and grease, so I will refurbish the hub motor from my fat bike with these. And then most likely put it up for sale (provided I am happy it is working perfectly)

I've more or less decided that my end game, and the only bike I will end up with, will be a full suspension 29" MTB (with as wide a tyre as it will fit, hopefully 3"), with a Bafang BBSHD motor. So that's what I will be working towards over the next few months...

SCOL

EU 48V 13Ah lithium ion silver fish electrical ebike battery fits 750W motor for $220
this comes with a charger ?

I like the idea of making my own battery, could I make a better battery for less money ?
and also I would need to buy a charger ?