Noobie planning an Electric bike with >30 mph

[Drunkskunk]

The thing about Direct Drive hub motors are that they don't do to well on steep hills. And me being a "heavy rider" weighing in at 110 kilo I don't think direct drive motors will do it for me. Not only because I am heavy but also because there are a lot of ups and downs hills on the way to work.

Yeah, that's not even wrong, It's completely off the mark.

Here's a short vid of a direct drive pulling up a few hills.
[youtube]5JPDF1V7Brg[/youtube]

Direct drive can handle larger hills and more weight. They just aren't as efficient doing it. Lets compare two 500w motors, the MAC and the 9C. A geared motor like a MAC makes around 25% more torque at it's peak power (1500watts) than an equivalent speed 9C motor at the same power.(which is direct drive). However, the 9C can be pushed up to twice the power(3000w), making far more torque. Direct drive make up for less initial torque by being able to shed a lot more heat.

While you can oil cool a geared motor to shed a little more heat, melting of the windings is only one failure mode. the gears can simply self destruct from too much torque, regardless of how cool you keep them. If you're running at the point where you need active motor cooling on a geared motor, you're running them on the verge of self destructing.

 

[macribs]

Great video skunk I check out the Austin Hills also. Your tomato is fairly heavy bike I guess. May I ask what is the combined weight of you and your bike? I must have been misinformed or probably more accurate I have misinterpreted what I've read regarding all the wonderful things about geared hub motors. Your statement contradict what I thought was a fact.

Well except for the extra weight of direct drive this is very good news for me, as direct drive motors seems less costly. And as they have a larger surface area they will stand the heat better. So will a fork stand up to the test of a 2WD DD set up? Torque arms included......

According to your calculation 2 x 9c would give me peak output of 6.000 watt? Well I guess then even a fat bloke can fly
What kind of speed will I see with a 72V or 96v battery pack?

 

[macribs]

I commute 16Km everyday, the kit I started out with was a 1000W Direct Drive hub motor, and a Lithium Ion 48v 15AH battery. 30mph all the way, everyday, reliable setup.

I'm also commuted with a BMC Geared motor briefly, 40mph top speed on 75volts. Very torquey motor and powerful but the motor heats up very quickly and you can't "crank" the throttle quickly or the gears would slip, its just not as durable as a direct drive.

I have direct drive setups that I commute with that regularly hit 40mph+, and are reliable.

Thx. First hand experience is king. Well then I have some more reading to do in order to decide which direct drive motor to go for
The cromotor mentioned by spinning magnets seems the tits although it retails for top dollar. I will need to gather more info of what can be achieved with the Cromotor compared to other Direct Drive hub motors. Might not be mandatory with a 2WD setup to gain acceptable speed, and durability. I think I will start off by looking and reading here at this great forum.

How is the acceleration from a direct drive in general, and the Cromotor in special compared to geared motors?

 

[middriveebike]

..I would prefer to loose the derailure and the cassette and use a single speed setup and enclose both sprocket and chain...

Why make it more complicated and more expensive by using CVT? Derailure and cassette would work just fine, at least for me. People say that if you are driving an automatic car, you are missing out a part of the driving experience.

 

[macribs]

..I would prefer to loose the derailure and the cassette and use a single speed setup and enclose both sprocket and chain...

Why make it more complicated and more expensive by using CVT? Derailure and cassette would work just fine, at least for me. People say that if you are driving an automatic car, you are missing out a part of the driving experience.

Well I discarded the initial idea of both belt drive and also CVT. But I am fairly sure I still would prefer to enclose both sprockets and chain.
Single speed also makes for a cleaner look, and if I do enclose the sprockets and chain I think it will mean less wear cos of no sand tearing between chain and sprocket. But mainly it is really just a fixed idea I got when looking at a certain bike a kickstarter. I just immediately felt I needed something similar, yet fully dampened.

Btw I have had both cars with sticks and cars with auto. I have some great memories from owning various rare and weird european and japaneese sports cars. They all had manual transmission. And they gave me great pleasures manhandling them on twisty roads.
As I am no longer a spring chicken racing around tight bends always hunting for maximal powerband of the engine I must say that for a daily driver I now prefer auto over manual, I choose a roomy saloon with leather and comfy seat over trumped up l a r g e turboed jap anyday.

But going electric is also about environment and small foot print as well as fresh air.

 

[macribs]

Well the cromotor mozilla looks sturdy. Expensive but a monster. Yet i can not let go of the idea of a 2WD just yet.
Imagine a cromotor in the rear with an direct drive motor in the front as well. I guess for even more steep climbing, or even mad acceleration one could choose a DD hub in the front that is made for higher torque. I saw one manufacturer had different windings for different usage.....with a set up like that I could run both motors at acceleration, steep hills etc and just shut off front motor when cruising speed is reached. Or one could do one better and program the controller to shut down automatic when certain speed is reached. Or even make a "flooring" function ie with a snap for full throttle use both motors when speed exceed a set point cut power.


What direct drive hub motors are winded especially for climbing and extra torque? Or could that torque wind be fixed with most motors if asked before purchase? I see Crystalate The Crown got different windings.


Possible one could experiment with different wheel sizes as well. Does mismatching wheel sizes f/r inflict any negative issues?

 

[biohazardman]

I commute 16Km everyday, the kit I started out with was a 1000W Direct Drive hub motor, and a Lithium Ion 48v 15AH battery. 30mph all the way, everyday, reliable setup.

I'm also commuted with a BMC Geared motor briefly, 40mph top speed on 75volts. Very torquey motor and powerful but the motor heats up very quickly and you can't "crank" the throttle quickly or the gears would slip, its just not as durable as a direct drive.

I have direct drive setups that I commute with that regularly hit 40mph+, and are reliable.

Likely gears not slipping but you were loosing sync as that's what it sounds like. Controllers programming must be spot on for your rated amperage and phase amps or it sounds awful and doesn't go fast. If that is not enough these parameters change as you change the voltage you run.

 

[Ohbse]

To achieve your stated goals affordably using the minimum amount of parts that are actually available for not ridiculous money:


~5kw, 20km range
Crystalyte H40 Direct drive hub, rear wheel drive. Ventilate covers to deal with heat. Dual beefy torque arms.
Adaptto mini-e. Set for 60a battery, make sure you configure the thermistor to ensure no heat related motor death.
72v nominal of lipo, 20s 10ah minimum. You can achieve this easily with 8x 5s 5ah bricks from hobbyking and a plug and play harness.

This setup will get you to work at 30-40mph, full throttle from every light with a little energy to spare. I know because I have a very similar setup, only with the smaller hs3540 motor.

If you would like to go faster, upgrade to a Crown/Cromotor and an Adaptto Max-E. If you want to go longer, buy some more lipo bricks or build an 18650 based pack using Sony VTC5 or LG HE2 cells.

 

[macribs]

To achieve your stated goals affordably using the minimum amount of parts that are actually available for not ridiculous money:


~5kw, 20km range
Crystalyte H40 Direct drive hub, rear wheel drive. Ventilate covers to deal with heat. Dual beefy torque arms.
Adaptto mini-e. Set for 60a battery, make sure you configure the thermistor to ensure no heat related motor death.
72v nominal of lipo, 20s 10ah minimum. You can achieve this easily with 8x 5s 5ah bricks from hobbyking and a plug and play harness.

This setup will get you to work at 30-40mph, full throttle from every light with a little energy to spare. I know because I have a very similar setup, only with the smaller hs3540 motor.

If you would like to go faster, upgrade to a Crown/Cromotor and an Adaptto Max-E. If you want to go longer, buy some more lipo bricks or build an 18650 based pack using Sony VTC5 or LG HE2 cells.

Yeah you know how it is, we often start out with one goal and then we fancy more as we see all the great stuff people put together. I was just thinking of a commute bike and not much more. But as I spend time here on this fantastic forum I get more and more drawn into the idea of "go big or go home"

I stated 40 mph would be a bonus. Yet when I see all the people riding 50 or even 60 mph, well lets just say an itch started.
And the craziest of it all is that many of the builders here ride their bikes like it was no tomorrow. They even bring their toy to go DH, or ride rough trails blazing fast. With jumps and twists and what not. And that might be worth exploring. Would imagine great power in a bike will give us the same joy of riding we once had as kids. Btw just as I started to feel I got a better understanding of how e-bikes works I came across yet another thread. This time is was The Specialized Big Hit FSR.
He went for a lighter motor, with smaller 35mm stator Crystalyte HT3525. To get max power out of that motor he went for 100 volt but reduced torque. 5.000 watt from that motor without risk of meltdown. So I guess more reading is the only way to get a better grip on what factors that affect the final output of an electric motor. From what I understand he get as much power from the cheaper HT3525 as others get from the Cromotor or the crown. And the bikes seems to respond well to the throttle, with fast pickup and overall good speed.

So you do not fancy the idea of 2WD? Better to get all power from one motor?

 

[Ohbse]

Unless you need more power than one motor can provide, or the accompanying factors with one powerful motor (single heavy axle etc) are not workable for whatever reason then I believe a much more simple single motor, rear driven setup is best for cost, complexity and predictability reasons.

A cromotor running >10kw on a Max-e will be more than enough for almost any sane person. Comparable performance to a mid range sport bike up until a certain speed if you keep the bike light. At that point it's pointless IMO having a second front motor as the front wheel will be off the ground anyway.

Things can get very, very expensive (for a bicycle anyway) once you start getting up in the speeds. >40mph motors need to be much larger or cooled, batteries need to accommodate the exponential increase in wh consumed which increases weight. Weight + speed leads to breaking everything that's not designed for serious abuse, you end up running high end downhill components or motorcycle parts, at which point it becomes borderline as to whether you would have been better off building a proper motorcycle from the get go.

Make sure you know what you're taking on before you pull the pin on a monster build, both in $$ and in what you're going to end up with. I have personally been thrown right off the back of my hard tail running 4.5kw and have some scars to prove it. I don't know you or your experience level or history, but for somebody with no 2 wheeled experience jumping to a 40kg 10+kw bike is probably a much shorter route to the morgue than most!

 

[macribs]

Well the reason I still am kind of hung up on the 2WD is that I am a heavy person. And I also live in an area littered with hills.
So my thinking was that a smaller, different winded front DD hub motor would help in acceleration, climbing steep hills and prevent flipping the bike in steep hills. Both motors engaged in start off till cruising speed is reached. Then switch off front motor. Or not if warp speed is the goal
But I got to say the more I read about the Cro mozilla it seems all the speed, acceleration and hill climbing a heavy person could ask for will be managed with a RWD.

So will there then be any advantages of going for 2WD? Well redundancy is nice. Less chance of overheating components is another. And then there are the extra traction, acceleration and less chances of flipping bike. If I will end up doing a 2WD I am not so sure anymore. As the cromotor seems to handle anything.

I have years of experience as a motorcycle riders, and started out with a motoX dirt bike like many other kids. Then there was scooters, sports bikes and later maxi scooters. But I haven't owned a bike for some years now. And all the threads about them crazy speed monsters here kind of makes me wanna do the same thing. A DH bike seems to me like the perfect bike to start with. Durable and strong frame, suspension and spokes. Yes they are hi priced, but I don't see the need to start out with a brand new DH bike. A second hand will do just fine.

I will try to plow through more threads and do even more reading this weekend so I get a more basic understanding of the physics behind it all, and learn more about what other have achieved with their builds.

 

[macribs]

If using a Cromotor @ 72v or 96 v what kind of acceleration can I expect?
In numbers, say 0-30 mph, 0-40 mph, 0-50 mph and ehh uhm 0-60 mph?

Have anyone tested? Sure the result will not be equal for me as I am a heavy dude. But it makes it easier to imagine what to expect, and where to draw the lines for this project. Acceleration can be even more addictive then share top speed.

 

[Brake]

Cromotor at 70v pulling 7kw 0-30 in half a block. Roughly 10:1 power to weight.
It all depends but I think power to weight ratio may help you get an idea.
Brake

 

[Tench]

This to me is a classic case of a noob wanting to run before he has learnt how to walk. No disrespect to you, you are here starting out on a journey we have all encountered before you. And my advice would be to build 2 bikes!

First go with a rear HS3540 dd hub in a 26" steel commuter bike with a V2 CA and 40a controller fed by 10 4s 5ah hard case packs arranged for 72v and 10ah, this is for your journey needs. Building it will be a very valuable experience equipping you with far greater knowledge and a little feel and experience to then decide on the fun bike build spec.

You may feel building 2 bikes is added expense, I would say not, the first build will open your eyes to help ensure you get the expensive power build right first time without wasting money. You will also still have your commuter when the power bike is laid up with a burnt/fried component.

Then on the power bike you can have the programmable controller if you wish and the V3 CA. The programming of these alone is still not something I want to take on yet! So I would advise a simple straight forward plug and play commuter build first.

 

[macribs]

This to me is a classic case of a noob wanting to run before he has learnt how to walk. No disrespect to you, you are here starting out on a journey we have all encountered before you. And my advice would be to build 2 bikes!

You will also still have your commuter when the power bike is laid up with a burnt/fried component.

Then on the power bike you can have the programmable controller if you wish and the V3 CA. The programming of these alone is still not something I want to take on yet! So I would advise a simple straight forward plug and play commuter build first.

What you say makes sense. A daily rider might not need all the hi end techy stuff. Nor the hi speed or great acceleration. About the programming I am not worried. For years I made a living out of vb, c+, c#, python and .net. Even if software is written in a language I don't have first hand experience with I feel it will be doable. A go-fast-thrilling-accelerate-hooligan bike is for sure gonna be made. But I might take your advice and make a sane bike first.

 

[MadRhino]

I see nothing wrong about building a powerful bike at first try, if you are a rider to handle it. H motors are lightweight and fun at 10 Kw, but they don't last very long when you beat them. A bike built 70 Lbs, cromotor in a 24" wheel, with an 18 fet 4110 set to pull 150A off 24s lipo, is enough to scare most dirt riders. It accelerates like a 250cc MX without a clutch

 

[macribs]

I see nothing wrong about building a powerful bike at first try, if you are a rider to handle it. H motors are lightweight and fun at 10 Kw, but they don't last very long when you beat them. A bike built 70 Lbs, cromotor in a 24" wheel, with an 18 fet 4110 set to pull 150A off 24s lipo, is enough to scare most dirt riders. It accelerates like a 250cc MX without a clutch

Alright! Thank you MadRhino.
Acceleration like a 250cc Mx now that is great fun. That will help my "midlife crises" for sure
Yet cheaper then a Porsche and more fun to ride.

What about the cromotor, will it last with that kind of power?

 

[MadRhino]

It will last if you keep the rides short. You can't feed a hub motor to saturation, hard accelerating repeatedly for a long ride, not until they make them liquid cooled. I ride 24s 1p most of the time, that doesn't let you ride long enough to fry a big hub, unless you act stupid while climbing very steep.

 

[999zip999]

It' just how much time before melt down.

 

[MadRhino]

It' just how much time before melt down.

Yep, once you know the limit you can make it last very long. My Demo 8 has over 35 000 Km done with the cromotor 1 never opened, on and off road, riding very aggressively for short rides less than 15 Km.

 

[Tench]

The different opinions of how you should proceed are all correct, each one coming from some ones previous experience of their own builds that they are happy with. So how you proceed is up to you. When you come up with a plan and detailed spec run it by the ES to see if there is any obvious incompatability with your parts or spec choices then go for it!

 

[underdog]

I feel like weighing in here. I hope you dont mind...

Having gone threw all the same considerations, ideas and thoughts you are doing here, I can imagine the confusion. Since cost is an important factor, and learning is one of the side goals, I say "build to wreck". In the last two years I have tried ALOT of different setups. For a first build, I would say simplicity is the key. Over-complexing everything will have you frustrated spending most of your days in the garage insted of the road.

Before going all out buying expensive parts, you should fry at least one cheap part. My favorite "cheap" motor is the 9C (or 9C-clone). Its cost-efficient, yet posesses the potential of 70 km/t if used correctly. If you worry about hill-climbing and torque, just put a 24 inch rim insted of a 26 inch on it. Abuse this motor until it takes suicide. By that point you have enough experience to buy expensive (hopefully having learned what not to do). :lol: The problem of building fast bikes is that they are inspiring, and as time pases, you will always want "just a little bit more". And at some point, something is going to brake down. Better to have spent 100 USD than 350 og 450 USD when that happens... And belive me, a 9C has enough power to kill you without hessitation. No need for a cromotor to do that!

I Wish you all the best on build. Do share pics on the way.

Regards
Magnus

 

[macribs]

It will last if you keep the rides short. You can't feed a hub motor to saturation, hard accelerating repeatedly for a long ride, not until they make them liquid cooled. I ride 24s 1p most of the time, that doesn't let you ride long enough to fry a big hub, unless you act stupid while climbing very steep.

Hm you know in the fun of it all, it is possible to forget the heat build up. Maybe I should see about liquid cooling that cromotor just to be safe.

I've found maybe a solution for the batteries, the new Sony VTC 5.

Sony VTC5 18650 2600mAh 30A


Model SONY-VTC5
Producer Sony
Type 18650
Max discharge current 30 Ampere
Capacity 2600 mAh
Nom voltage 3,7 volt
Full voltage 4,2
Recargable Yes
Battery type Hybrid IMR Li-Ion
Weight 44 gram
Length 65,2 mm
Diameter 18,45 mm

Seems those hybrids will pack more punch, not as much a lico but as a crossover more safety as well. But those are expensive so you wouldn't believe. So still got my green sun screen cap on and are doing some calculations.

I thought maybe a 24S5P setup. That would give me 96 volt nom but close to 110 v peak so then I can not use the Adaptto Maxi E.
But I can use one of the Lyen controllers with the hi voltage IRFB4115 MOSFET's. That controller will not cap at 98v. Ot will go all the way up tp 132 v.

Just for the fun of it will a 30S5P give noticeable more acceleration and top speed then 24S5P?

And what kind of power will the cromotor be able to draw from the controller at full throttle?

Have yet to sort out BMS. So I will keep looking and reading up on that as well.

...................................................................................................................................................................

It' just how much time before melt down.

Yep, once you know the limit you can make it last very long. My Demo 8 has over 35 000 Km done with the cromotor 1 never opened, on and off road, riding very aggressively for short rides less than 15 Km.

Good point made MadRhino. I am focusing to much on the heat build up.

.......................................................................................................................................................................

The different opinions of how you should proceed are all correct, each one coming from some ones previous experience of their own builds that they are happy with. So how you proceed is up to you. When you come up with a plan and detailed spec run it by the ES to see if there is any obvious incompatability with your parts or spec choices then go for it!

Great advice, I will be sure to do that. Thx.


.......................................................................................................................................................................

I feel like weighing in here. I hope you dont mind...

Having gone threw all the same considerations, ideas and thoughts you are doing here, I can imagine the confusion. Since cost is an important factor, and learning is one of the side goals, I say "build to wreck". In the last two years I have tried ALOT of different setups. For a first build, I would say simplicity is the key. Over-complexing everything will have you frustrated spending most of your days in the garage insted of the road.

Before going all out buying expensive parts, you should fry at least one cheap part. My favorite "cheap" motor is the 9C (or 9C-clone). Its cost-efficient, yet posesses the potential of 70 km/t if used correctly. If you worry about hill-climbing and torque, just put a 24 inch rim insted of a 26 inch on it. Abuse this motor until it takes suicide. By that point you have enough experience to buy expensive (hopefully having learned what not to do). :lol: The problem of building fast bikes is that they are inspiring, and as time pases, you will always want "just a little bit more". And at some point, something is going to brake down. Better to have spent 100 USD than 350 og 450 USD when that happens... And belive me, a 9C has enough power to kill you without hessitation. No need for a cromotor to do that!

I Wish you all the best on build. Do share pics on the way.

Regards
Magnus

Hm well if one was to try that as a baby step approach what would I be able to do with a 9C, a Lyen controller and a buttload of LiFePO4 batteries? I mean if I should go this route I would have to use cheaper components elsewhere also. Not sinking in 2-3K in batteries just to save 200 $ on a motor. Will a LiFePO4 battery pack give enough punch to be able to reach 70 Km/h? How far can I ride on a 96 volt 15 Ah setup? Will the acceleration be whooping fast with a 24" wheel mounted 9c and 96 volt 15 Ah?

 

[Brentis]

With all due respect, you need to stop asking these repetitive ?'s.
This battery, that controller, how about these motors etc.
You have been given valuable info from several members that have spent a great deal of time and energy to answer and walk you through the basics.
I'd suggest you stop, reread this thread about 3 times.
Use this valuable ebike tool ebikes.ca/ebikes simulator
Then you'll be better equipped to understand the relationships between the various components and the basic theories that have been given to you.
If you are for real and not just dreaming about bikes, you will find less and less help if you ask the same ?'s repeatedly.
Nobody wants to waste their time.
Hope that isn't too harsh.

I'd suggest you walk before you run.
From reading your other thread you started wanting a commuter.
Start with that, a basic hub kit that you can cut your teeth with and understand the limits of the various components.
50kph is a very realistic for a 48v kit, you don't need 96v cromotor setup to have the e grin. Enjoy that, out grow it then build the next fix.

Good luck

 

[underdog]

I feel like weighing in here. I hope you dont mind...

Having gone threw all the same considerations, ideas and thoughts you are doing here, I can imagine the confusion. Since cost is an important factor, and learning is one of the side goals, I say "build to wreck". In the last two years I have tried ALOT of different setups. For a first build, I would say simplicity is the key. Over-complexing everything will have you frustrated spending most of your days in the garage insted of the road.

Before going all out buying expensive parts, you should fry at least one cheap part. My favorite "cheap" motor is the 9C (or 9C-clone). Its cost-efficient, yet posesses the potential of 70 km/t if used correctly. If you worry about hill-climbing and torque, just put a 24 inch rim insted of a 26 inch on it. Abuse this motor until it takes suicide. By that point you have enough experience to buy expensive (hopefully having learned what not to do). :lol: The problem of building fast bikes is that they are inspiring, and as time pases, you will always want "just a little bit more". And at some point, something is going to brake down. Better to have spent 100 USD than 350 og 450 USD when that happens... And belive me, a 9C has enough power to kill you without hessitation. No need for a cromotor to do that!

I Wish you all the best on build. Do share pics on the way.

Regards
Magnus

Hm well if one was to try that as a baby step approach what would I be able to do with a 9C, a Lyen controller and a buttload of LiFePO4 batteries? I mean if I should go this route I would have to use cheaper components elsewhere also. Not sinking in 2-3K in batteries just to save 200 $ on a motor. Will a LiFePO4 battery pack give enough punch to be able to reach 70 Km/h? How far can I ride on a 96 volt 15 Ah setup? Will the acceleration be whooping fast with a 24" wheel mounted 9c and 96 volt 15 Ah?

Baby steps approach would be to buy a complete 500w kit and lug it on a bike, and upgrading piece by piece from there. I would not feed a 9C that much volts in stock configuration. I have been running a stock 9c at 74 volts, and that is just about the limit before it starts arching inside. When I go all out in low speed I can actually hear (and feel) the arching. If you want more volts you can open and modify it accordingly, with bigger phase wires and what not. Maybe slap a thermistor in there for your CA3, for added lifespan even. Its the perfect motor for modifying and learning the tricks of the trade. I dont know why you would considder it a noob-solution. To much bike-porn lately perhaps?? :lol: And acceleration-wise: I wheely with my 48volt 30A 9c with treangel-mounted pack easy.

Where in Norway do you live by the way?