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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]

To make things easier and to save me breaking the battery up all the time for parallel charging I got a charger for the voltage I wanted for LiPo of course , at the time I was running 16S LiPo, so I wanted it to cut off at 66.4 Volts charging to 4.15 V per cell so it would connect the charger with the pack in series, in other words, I didn't have to break the pack up to charge on the RC balance charger if the cells were reasonably balanced and only put it on the balance charger once every week or two to balance the pack, as I said earlier, it will go out of balance if you take the voltage low enough so either get more battery or try not run it down so low.

unkel

I don't mind plugging and unplugging a few XT60 connectors for charging. Doing it only once a day anyway.

Well, you've converted me already to lipo so!

Thanks for all your help, man. I think I will have some more ordering to do in the next few days. Lots of stuff for projects to keep me busy all winter. Can't wait to test those lipo cells with a cheap pure sine wave inverter as a mini REx for my car too - should add about 3km range in 10 minutes of charging if the inverter can hold peak charge for that long

[Deleted User]

unkel wrote: »

I don't mind plugging and unplugging a few XT60 connectors for charging. Doing it only once a day anyway.

Well, you've converted me already to lipo so!

Thanks for all your help, man. I think I will have some more ordering to do in the next few days. Lots of stuff for projects to keep me busy all winter. Can't wait to test those lipo cells with a cheap pure sine wave inverter as a mini REx for my car too - should add about 3km range in 10 minutes of charging if the inverter can hold peak charge for that long

Haha good luck with that.

Yes LiPo is great for ebikes, just charge in a safe place and store it in the shed, just remember performance will suffer when it gets cold and you will notice it's sluggish with more voltage sag, if your setup isn't pulling enough current to notice then it won't matter.

Or store it in a safe place in the house with a smoke alarm close by.

unkel

All stored and charged in the shed

Lumen

unkel wrote: »

Haha I like the analogy

I want both really. I want to still be able to pedal, but also want it to move at reasonable speed (say 30-35km/h) on its own.

But you agree that the torque on the chain and the gears of a mid motor is pretty brutal. Don't know what you can do about that, except maybe have a clutch mechanism that takes the torque away from the chain / gears while you are changing gear. But that really starts to sound like a slow motorcycle with a manual gearbox to me...

As the father of many bicycle-related bad ideas, and also an enthusiastic user of both motorcycles and bicycles, I recognise the one X to rule them all as a bit of a "design smell".

There are good reasons that bicycles are 10kg and motorcycles are 150kg+, and not just that our political-correctness-gone-mad-nanny-state won't let us have any fun.

I respect Mad_Lad's passion and knowledge in matters of electric propulsion, but his expectations of performance are definitely at the motorcycle end of the spectrum, claiming as he does to have achieved 90kph on an electric bicycle (and presumably on the flat).

A pro cyclist is happy to go up a steep hill at 30kph, putting out perhaps 600W for a handful of minutes. You're talking about kilowatts of power. Time passes differently on a bicycle than it does on a motorbike - I can while away 3 hours on a bicycle no bother, but that time on a motorbike is incredibly tedious. So perceptions of speed and time are relative.

Aside from anything else, crashing faster than 35kph without proper protective gear tends to be quite physically damaging. I have crashed at ~55kph twice in lycra, and the second time I had to go on a course of strong antibiotics as the tarmac wore a hole in my elbow all the way down to the synovial membrane.

Anyway, much as I love motorcycles (and would love an electric one when they're not €30k+) I think there's something to be said for the Colin Chapman-esque principal of virtuous lightness and simplicity which gets lost once you move away from a conventional derailleur-based electrically-assisted drivetrain limited to perhaps 500W. You might go faster but you won't necessarily enjoy it more once the initial rush of speed has worn off.

unkel

Lumen wrote: »

I have crashed at ~55kph twice

Ouch! I have no intention of ever going over 35-40km/h and only on a straight flat deserted cycling lane on my bike with fat tyres, not down a twisty mountain road on a race bike!

Slow motorcycle it is for me, I don't want anything to do with a fast bicycle

[Deleted User]

Lumen wrote: »

There are good reasons that bicycles are 10kg and motorcycles are 150kg+, and not just that our political-correctness-gone-mad-nanny-state won't let us have any fun.

I respect Mad_Lad's passion and knowledge in matters of electric propulsion, but his expectations of performance are definitely at the motorcycle end of the spectrum, claiming as he does to have achieved 90kph on an electric bicycle (and presumably on the flat).

Aside from anything else, crashing faster than 35kph without proper protective gear tends to be quite physically damaging. I have crashed at ~55kph twice in lycra, and the second time I had to go on a course of strong antibiotics as the tarmac wore a hole in my elbow all the way down to the synovial membrane.

Indeed I did manage 90 Km/hr, it's not difficult what so ever, just add voltage for more speed and Current for more torque.

50 Km/hr on the other hand is a good safe max for any Bicycle, you can come off it going down a hill at 60 Km/hr, once the brakes have been upgraded 50 Km/hr is no big deal.

Now , I'm not suggesting our wonderful leaders allow 50 Km/hr , 35 Km/hr ( 21.7 Mph ) for max motor assistance would have a big impact and make much more sense. 25 Km/hr cut off is just too low.

Remember Legal ebikes ( S-Pedelec ) that go 50 Km/hr are allowed with tax and insurance.

We already know the 250 watt power limit is well exceeded with the big players in the Ebike business.

SlowBlowin

If I tuck down and am on a nice downhill section my ebike will do 70 kph, so I totally believe ML can pull 90 kph with 3 times my power.

Some people who are technically minded will always want to push the limits to see what is achievable, I believe ML is one of those people (so am I). If I get a laser pointer, I want modify it to make it burn, if I get a drone I want to make it fly further. This is how progress is made, and a good deal of progress is still made in the garden shed by the modern day eccentric.

I am not saying you are wrong, far from it, the attached picture is from my early eBike speed trials, my last look at the speedo showed 50kph then a few seconds later a sheep decided to jump onto the bike from rock ledge above the lane. The bone was split from the top, hands and knees were a mess, 3 months off work, and my speed trials were at an end. I still use the same bike (rebuilt), and its grand, just what I want although I don't think its been over 50kph since.

Attachment not found.

So whereas I don't disagree with anything you say, I would feel terrible if I was not allowed to experiment, its in my nature and as ML says the current legislation could do with more realistic power and speed levels.

unkel

Got two of these babies in the post today

I used these before on my direct drive motor kit and they weren't as suitable as that motor / controller drew 930W out of them at full throttle, which was far too much for them to survive doing that for a year or so

Deleted User wrote: »

I'd keep your current bike to be honest

They are however, very suitable for my current bike as the 7A controller only makes it draw 250W. And a 100% legal pedelec setup. Tempted to sell it with the battery as a completely working eBike (without butchering it) and use the proceeds to start a new built of a more mid range bike. Tempted by a 29er setup. New or second hand. I'm a bit under 6'2 (1.87m) and fairly heavy at 100kg, so a big bike would suit me

Thoughts of a setup? I have 30A controller and throttle on the way and can make basically any size / voltage battery from 18650s (and maybe later upgrade to the lipo that Mad_Lad suggested)

How to motor it though? I like the geared hub setup, but would need a motor that can take 2kW without going up in flames or melting its gears

[Deleted User]

unkel wrote: »

Got two of these babies in the post today

I used these before on my direct drive motor kit and they weren't as suitable as that motor / controller drew 930W out of them at full throttle, which was far too much for them to survive doing that for a year or so

They are however, very suitable for my current bike as the 7A controller only makes it draw 250W. And a 100% legal pedelec setup. Tempted to sell it with the battery as a completely working eBike (without butchering it) and use the proceeds to start a new built of a more mid range bike. Tempted by a 29er setup. New or second hand. I'm a bit under 6'2 (1.87m) and fairly heavy at 100kg, so a big bike would suit me

Thoughts of a setup? I have 30A controller and throttle on the way and can make basically any size / voltage battery from 18650s (and maybe later upgrade to the lipo that Mad_Lad suggested)

How to motor it though? I like the geared hub setup, but would need a motor that can take 2kW without going up in flames or melting its gears

Bear in mind, you have less torque with a 29er than with a 26 and it puts more stress on the motor.

So I'd highly recommend a Mid drive such as BBS02 or BBSHD from Bafang, best thing about chain drive is that you have the torque in any gear and you need less power, it's easier on your batteries too on the hills.

You'll never look back, hubs are grand and continuous uninterrupted power is great but chain drive is the way to go to be honest.

I wish I could go back to ebiking but I don't get the time and no cycle lanes for Kids in the country , dangerous roads etc it's just horrible, I'd take the lads to School no problem if I had proper cycle lanes and they were safe, country lanes that you have to stop and pull in to allow another car pass is just not good and the speed of drivers on these roads is ridiculous, People just don't think and worse, they don't care.

Having said that, I wouldn't take them on Dublin cycle/Bus/taxi lanes either, ridiculous !

unkel

Deleted User wrote: »

Bear in mind, you have less torque with a 29er than with a 26 and it puts more stress on the motor.

So I'd highly recommend a Mid drive such as BBS02 or BBSHD from Bafang, best thing about chain drive is that you have the torque in any gear and you need less power, it's easier on your batteries too on the hills.

I hear ya. No hills here though to speak off though. And realistically I only use the bike as a local runabout, for a local commute (5km each way) and for taking the dog out.

Also mid drive is well outside my comfort zone to set up, I don't even have the tools to take the bottom bracket out.

And the mid motor setup makes it looks like an eBike in the most obvious way. A Garda probably wouldn't even recognise a bike with a small geared motor as an eBike if you have the battery somewhere discreet (like in a back pack) - stealth!

[Deleted User]

unkel wrote: »

I hear ya. No hills here though to speak off though. And realistically I only use the bike as a local runabout, for a local commute (5km each way) and for taking the dog out.

Also mid drive is well outside my comfort zone to set up, I don't even have the tools to take the bottom bracket out.

And the mid motor setup makes it looks like an eBike in the most obvious way. A Garda probably wouldn't even recognise a bike with a small geared motor as an eBike if you have the battery somewhere discreet (like in a back pack) - stealth!

Taking out the bottom bracket is dead easy.

Tools are readily available.

Guards, couldn't care less, just don't make a nuisance of yourself and you'll be grand.

A hub is find alright if you have no hills and yea , Lucan is dead flat, compared to here anyway, I got a lot of steep hills.

Just don't forget your torque arms if going above 1 Kw !

unkel

Maybe I should just go another wheel kit with a direct drive motor. RWD this time. It will handle all the power I will throw at it (up to say 30A * 58.8V battery or who knows even a higher voltage battery) with ease, so I won't have to worry about the health of a geared hub motor

The main drawback is that if the battery is gone, it will be hard to cycle home but not impossible? And I can still cycle normally on it by pedalling, if I keep at least a bit of throttle open at all times?

[Deleted User]

unkel wrote: »

Maybe I should just go another wheel kit with a direct drive motor. RWD this time. It will handle all the power I will throw at it (up to say 30A * 58.8V battery or who knows even a higher voltage battery) with ease, so I won't have to worry about the health of a geared hub motor

The main drawback is that if the battery is gone, it will be hard to cycle home but not impossible? And I can still cycle normally on it by pedalling, if I keep at least a bit of throttle open at all times?

You should be able to pedal a geared hub without motor power easy enough, much easier compared to direct drive hub.

58 v x 30 amps is 1.7 Kw, that will be probably too much for those little hubs , go easy on the throttle and definitely install torque arms.

unkel

Deleted User wrote: »

You should be able to pedal a geared hub without motor power easy enough, much easier compared to direct drive hub.

58 v x 30 amps is 1.7 Kw, that will be probably too much for those little hubs , go easy on the throttle and definitely install torque arms.

Re-read my post. I'm talking about direct drive

[Deleted User]

unkel wrote: »

Re-read my post. I'm talking about direct drive

Jaysus, hard to keep up, either way, time for torque arms.

unkel

Yeah, I admit I am all over the shop with my thoughts, ideas and plans

I'd like to try all sorts of setups. I know you highly recommend a Bafang mid motor setup as you were very happy with it and you had great craic with it climbing up steep hills. But you do have a tendency to recommend things to other people that work well in your circumstances but might be less relevant to others. There's a bit of that in myself!

I'd like to give a mid motor a try, but it would cost more money than I could justify and it would leave me with a setup that I don't have a need for

I think I'll just settle for a half decent mid price 29er MTB, then when I get that hub motor, I will get my local bike shop to lace it for me in my front wheel. And then just pedal the bike and sent up to a moderate amount of power to it whenever I feel like it, but say rarely more than 1kW, and when so then just for a few seconds, not continuously, and hope for the best.

Current eBike went up on adverts.ie this evening...

unkel

And I will get torque arms!

SlowBlowin

unkel wrote: »

And I will get torque arms!

and not arms like mine......

unkel

Hard to take into account crazy sheep jumping on you and your bike

kiely182

I've bought a 52v kit from the youtuber Andy kirby for 900euro I've done nearly 4000miles on it since April.only problem I've had is a few broken spokes. Battery is still going strong with no noticeable degradation

unkel

Yeah I watch all his stuff, subscribed to his channel. Really like him and the music in his vids is a step up from the pack. And he produces that music himself. I've linked to him once or twice in this thread already.

Not cheap his kits though. GBP739 for a kit with a really cheap direct drive motor wheel, but it has a programmable controller and in fairness a hefty 52V 17Ah (880Wh) battery

Linky

unkel

eBike sold. What's next?

unkel

Right. After watching this:

linky

I'm sold. I'm going to get a fat bike. And think about electrification later

Any recommendations? New or second hand, what size frame and tyres would be best for me (a bit over 6'1, a bit under 100kg)?

unkel

How about

Linky

[Deleted User]

unkel wrote: »

How about

Linky

For a road bike ? unless doing a lot of off road I wouldn't bother, wheels too thick too, I like to pedal a lot and the tyres would greatly increase resistance.

unkel

Deleted User wrote: »

For a road bike ? unless doing a lot of off road I wouldn't bother, wheels too thick too, I like to pedal a lot and the tyres would greatly increase resistance.

I'd say I'm going to take it off road :cool:

Used to do a good bit of hiking in Wicklow, would love to do same on a bike. Here's hoping I can get both bike and dog into Ioniq

krissovo

$100 for this fat boy right now, I ordered one for the craic so hopefully it will fit in my boot.

https://engwebrand.com/?fbclid=IwAR1_e9qi-yZBEXEAmmR-Aeew-Vej4Y4-bFGHfh8yIGS-tWDkpxkR0C6U7kA

unkel

There's one of those on adverts.ie, saw it last night

That price can't be right though, it's ridiculous! Ordered one anyway, thanks for the heads up, krissovo! €91 for an eBike with free shipping to Ireland :eek:

[Deleted User]

That's a mad price, let me know how it turns out.