What component does what regarding speed limit?

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nosmo   1 mW

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What component does what regarding speed limit?

Post by nosmo » Jun 11 2013 3:22pm

Hi,

I am glad a found this forum, its hard to find info on e-bikes, much harder then on RC vehicles.

I am planning in buying a conversion kit and a new bike with it. This is a cheaper option then an e-bike and I have more tweaking options.
My plan is to make my bike a bit faster then the 25km/h (15mi/h), rather go 30-35 km/h max.

Most conversion kit motors are 250Watt, which is country regulation. People say a higher speed is possible at 36V with a 250W motor, but I dont understand what limits it, programming or hardware?
Is it the motor, the motor controller or the LCD display?
The luxury conversion kits have a nice 5 or 6 step LCD display with an option to alter the max speed limit.

So I am a bit lost, where is the speed limit cap regulated?

Can anyone give me some insight on this?

Thanks
Last edited by nosmo on Jun 11 2013 3:27pm, edited 1 time in total.

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wesnewell   100 GW

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Re: What component does what regarding speed limit?

Post by wesnewell » Jun 11 2013 3:27pm

Please go to the User Control Panel, select Profile, and then enter your city, state/province, and country into the Location field (country minimum) and save it. This will help people help you. Example: Wylie, TX, USA. Without knowing what country you are in it's hard to make any recommendations. Thank you.
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Mongoose 26" Ledge 2.1 mtb bike $99, yescomusa.com 48V 1000W rear hub kit $200, Hua Tong 72V 40A controller $35, 10ah 24s lipo $217=~43mph, range=45 miles @ 20mph. 25K miles and still going strong.
Huffy Fortress 3.0 with MXUS 3000 4T motor, 24s lipo, 96V 60A controller. Total cost with extras <$700. Top speed ~50mph
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Re: What component does what regarding speed limit?

Post by electr0n » Jun 11 2013 3:52pm

Any electric motor will go faster the more voltage you give it. The limitation will be in the controller that comes with the kit and the maximum voltage it will accept. There may also be hard wired speed limits in some controllers as well. The smaller motors will also be limited by the maximum power they will accept without burning up. When a motor is being sold as 250 watts or whatever that's really just a guideline and you may increase the power somewhat by increasing the battery voltage as long as the controller will handle it.

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Drunkskunk   100 GW

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Re: What component does what regarding speed limit?

Post by Drunkskunk » Jun 11 2013 4:16pm

Welcome to the forum.

Not every kit is going to be the same. Some may limit the top speed by the motor's voltage. Meaning at 36 volts, the fastest the motor can go is still under the speed limit.
Others will limit the speed by software. The controller will override the throttle once a certian speed is reached, or limit the current so that only enough power can be used to reach a certian speed.

I know that many of the Infineon controllers have a 2 wires externaly connected that are the speed limiter. simply unplugging them allows greater speed. But the design is such that an internal solder connection could be made by the vender to limit the speed, and would need to be desoldered to unlock the greater speeds.
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Re: What component does what regarding speed limit?

Post by Blackssr » Jun 11 2013 5:42pm

wesnewell wrote:Please go to the User Control Panel, select Profile, and then enter your city, state/province, and country into the Location field (country minimum) and save it. This will help people help you. Example: Wylie, TX, USA. Without knowing what country you are in it's hard to make any recommendations. Thank you.

Wes, how many times do you think you have said that on this forum? :D ... You are like the location police.... :lol:
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friendly1uk   10 MW

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Re: What component does what regarding speed limit?

Post by friendly1uk » Jun 11 2013 5:59pm

Have you been looking at the Q100 motor? In a 26" wheel the 201 variant is limited to 15mph by the controller. Turn the limit off and 18mph is about it. The 328 variant will manage about 20-22mph and respond well to a bit of pedaling. That is about the 250w limit. You can get to the speed you require, but any sort of wind or hill will have a large effect. It won't like working under 15mph though, it would burn out. Slower you went, the quicker the motor would overheat. Check out the ebikes.ca simulator for the figures. It draws nice plots for motor and battery combinations. It's an excellent tool. The 201 is slower, but puts up a better fight against the wind and does a better job of going slower. Resisting overheat better.

I expect to be happy with the 328, except for the burning bit. I'm going to use the same 250w controller, on a similar motor, that can take more power. I will still be using the 250w controller, so no power change. The motor will just be more capable under stress. As a bonus, moving from a mini motor to a mid sized gives some leverage advantage. But gains 2kg.

The geography I have seen over there was great for bikes. If your used to cycling, and it's long straight roads, with little time spent under 15mph, the Q100 328 might be ideal. It can also lead to disappointment and offers no real upgrade path. You need to be sure it will be enough. I don't think it offers any lasting fun factor, It just leads to a rapid cycle. One is on the simulator. I'm not sure which.


They call them kits, but it is a kit of all the bits everyone will definitely need. Anything specific to your bike won't be included. Consider torque arm fitment before you buy the bike, along with how your battery pack is going to mount and if using a pedal assist sensor you might need another crank thats long enough to hold it.

Because I want my wheels to match I went over 1000 hurdles and burnt off £125 from my wallet. It can cost more than expected.
bmsbattery sent me broken and incorrect stuff, and won't even talk to me about it.

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Re: What component does what regarding speed limit?

Post by d8veh » Jun 12 2013 4:19am

When you convert a bike with a kit, you can make the speed whatever you want. The first consideration is the motor speed. 201 rpm is 25 km/h at it's nominal voltage. Batteries spend most of the time at about 10% above their nominal voltage, so a 201 rpm motor will actually spin at about 220rpm or 28km/h. You can increase the speed of the motor by using a battery at a higher voltage than the motor's nominal voltage, so if you go from say 36v to 44v (actually from 40v to 48v), the 201rpm motor spins at 268 rpm or 34 km/h. Always ask for the motor RPM when buying a kit or motor because it immediately gives you an idea of the speed potential and what battery you need. You'll notice that many motors are 201 rpm because that's the European limit.

The Chinese controllers and their associated panels are not normally restricted in any way, but if you buy a more expensive European kit, or a Chinese kit sourced in Europe it may well be limited by the supplier. Many of the newer Chinese kits have LCD displays, where you can get into the settings and change the speed limit.

If you find a kit/components you like, post the details here and we can advise you on whether it can reach your target speed or what you can do to change it.

Some guys on Pedelecs forum have had success to increase the speed and power of cheap European supplied Chinese kits with 201 rpm motors by adding a small booster battery. The booster battery can be made from cells from laptop batteries that you can get for a few euros, although you need an additional charger that costs about 20 Euros:
http://www.pedelecs.co.uk/forum/electri ... d-48v.html

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dogman dan   100 GW

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Re: What component does what regarding speed limit?

Post by dogman dan » Jun 12 2013 5:42am

In general, if you buy a more powerful direct drive kit from a vendor outside of your country or region, you will see about 30-35 kph from 36v, and 40-45 kph from 48v. Vendors in country, or in Europe may be more likely to sell kits with slow top speeds. USA allows 32 kph in most places, so slow kits don't sell here much.

The same direct drive motors can get to 65 kph on 72v.

As you increase voltage, the no load rpm of the motor increases. If amps remain the same, total wattage increases as you increase voltage as well. So more volts tends to mean more horsepower.

4 things affect real world motor speed.

1 voltage. For a given motor, more voltage gives faster rpm.

2 motor winding, combined with wheel size. At a given voltage, different winding arrangements in the motor determine motor rpm. A smaller wheel covers less distance per revolution

3 Actual speed limiting. Many controllers have a "euro mode" that roughly halves top speed that can be disabled. Some may include three speed switches to select three speeds vs two. Devices like a cycleanalyst can also have speed limiting functions.

4 wattage. It takes about 400w to go 35kph on flat ground. So a kit designed to provide only 250w typically wont reach 35 kph. Often very low wattage kits are low voltage, so if the controller will tolerate 36v instead of 24v, you can add a battery increasing voltage, and get to 400w. Or the same motor can run on more volts with a controller upgrade.

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wesnewell   100 GW

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Re: What component does what regarding speed limit?

Post by wesnewell » Jun 12 2013 11:18am

Blackssr wrote:
wesnewell wrote:Please go to the User Control Panel, select Profile, and then enter your city, state/province, and country into the Location field (country minimum) and save it. This will help people help you. Example: Wylie, TX, USA. Without knowing what country you are in it's hard to make any recommendations. Thank you.

Wes, how many times do you think you have said that on this forum? :D ... You are like the location police.... :lol:
Not enough, as there's still people that haven't filled in the location. It should be a required field during sign up, but no one has done it yet. Until it gets done, I'll just keep posting it in threads where the original poster doesn't have it filled in.
Need Advice? https://endless-sphere.com/forums/viewt ... =3&t=66302
Mongoose 26" Ledge 2.1 mtb bike $99, yescomusa.com 48V 1000W rear hub kit $200, Hua Tong 72V 40A controller $35, 10ah 24s lipo $217=~43mph, range=45 miles @ 20mph. 25K miles and still going strong.
Huffy Fortress 3.0 with MXUS 3000 4T motor, 24s lipo, 96V 60A controller. Total cost with extras <$700. Top speed ~50mph
My videos https://www.youtube.com/channel/UC0KW4U ... _G2wQhptMg

nosmo   1 mW

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Re: What component does what regarding speed limit?

Post by nosmo » Jun 12 2013 2:29pm

Wow, what many reactions, thank you all for replying!

I still have a lot to learn, motors, rpm, windings, power usage etc, they are all connected. I do have some experiance with rc heli's and brushless motors and lipo's, but bikes, high power motors is all new too me.

Reading all of your reactions I can conclude I probably need 48V if I want higher speeds. more voltage = more RPM. What I dont get is the 250W or 350W motor difference, do 350W motors have higher RPM at lower Voltage? Or they just draw less power? V * A = Watt

Higher voltage also means heavier battery, dont you want a lighter bike with the best top speed?
Ideal solution would be to have a 250W motor, running at 36V, using high density cells (NMC?).
250Watt is still legal, dont know if you can spot a 350W motor from the outside.
btw, my new bike will have 28" wheel size

are speeds of 35kmh (21mph) possible with a 250W motor at 36V?

Dont know if its allowed, but do people have links to shops, within Europe or outside, or can suggest some brands. Most used are the 8Fun motors I think.

The post about Q100 328, running slower speeds makes it too hot, I wil be cycling slower too.


Yep I am still a bit lost, have to re-read all these posts a few times to fully understand it all :)

Btw, country is mandatory during account creation, location isnt. Confusing bit is I filled in country, but I had to fill in the same info in location apparently.

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dogman dan   100 GW

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Re: What component does what regarding speed limit?

Post by dogman dan » Jun 13 2013 7:01am

Just knowing which continent is more or less enough, and I also wish that would appear automatically.

Keep reading, it only took me about 3 years to begin to understand about half of how motors work. Grin Cyclery has a really good FAQ page that explains motors.

It's hard to pin down the difference between a 250w motor and a 350w motor, unless you begin to talk in terms of a particular brand and model number of motor. In most cases, law enforcement will have no clue how to spot a 350 w motor in a place where the limit is 200 or 250.

Just pick a small motor, rather than a dinner plate size direct drive motor. Then run it at 800w or less. The motor can handle it. V times amps equals watts.

So make 15 amps of 48v, or 20 amps of 36v your controller size. Then when you see a cop, clown pedal like mad. You can legally pedal 40-50 kph right?

nosmo   1 mW

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Re: What component does what regarding speed limit?

Post by nosmo » Jun 13 2013 11:26am

Isnt there a golden combination? I mean for certain criteria there must be an advisable brand/type of motor, controller and battery right?

I want a bike that can go 35kmh max, front wheel, 28", not too visible and not too much noise. Rather use 36V because of the lighter battery. So what brand and type would suit my needs best? Thats the answer I am trying to find out on this forum.

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Re: What component does what regarding speed limit?

Post by d8veh » Jun 14 2013 4:01am

nosmo wrote:Isnt there a golden combination? I mean for certain criteria there must be an advisable brand/type of motor, controller and battery right?

I want a bike that can go 35kmh max, front wheel, 28", not too visible and not too much noise. Rather use 36V because of the lighter battery. So what brand and type would suit my needs best? Thats the answer I am trying to find out on this forum.
You can't always get what you want. 25km/h with a 250w kit and 10aH 36v battery will be light. When you want to go faster. it becomes more complicated. If you really want 35km/h sustained without too much pedal effort, you need something more powerful, heavier and more expensive. 35km/h with a 250w kit is possible, but you have too pedal quite hard as well.

I think that we need to go back to start and get all the info before we can recommend anything. All we know is that you want 35km/h and light:
How heavy are you?
How far do you want to go?
How hilly is the area where you want to go?
What bike do you want to convert?
How much do you want to spend?

nosmo   1 mW

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Re: What component does what regarding speed limit?

Post by nosmo » Jun 14 2013 4:34am

Hi d8vey, thanks you for your reply. You are right, hard to give advice without knowing all the details.

>How heavy are you?
about 74kg/163pounds

>How far do you want to go?
10km to and 10km back

>How hilly is the area where you want to go?
none, pretty flat over here :)

>What bike do you want to convert?
Dont know yet, want to buy a new one, that I can also use without electronic support

>How much do you want to spend?
on the conversion set, about 700 euro's, which is about $922

I want a front motor, not too big so its not very noticeable. A battery thats not too heavy. I want max speed of 35kmh with light peddling

I was looking at 8FUN-motor BPM (bafang) 350W motor with a panasonic 9,6a 36v battery, what I understood, these battery's are not as heavy.
Last edited by nosmo on Jun 14 2013 5:52am, edited 1 time in total.

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dogman dan   100 GW

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Re: What component does what regarding speed limit?

Post by dogman dan » Jun 14 2013 5:37am

Sustaining 35 kph will take about 400-600watts depending on the headwinds. So get a 36v 20 amps controller for that bafang. Then you will have 700-800w for those windy days.

Most of the time though, you will cruise with some pedaling closer to 400w.

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Re: What component does what regarding speed limit?

Post by d8veh » Jun 15 2013 4:02am

nosmo wrote:Hi d8vey, thanks you for your reply. You are right, hard to give advice without knowing all the details.

>How heavy are you?
about 74kg/163pounds

>How far do you want to go?
10km to and 10km back

>How hilly is the area where you want to go?
none, pretty flat over here :)

>What bike do you want to convert?
Dont know yet, want to buy a new one, that I can also use without electronic support

>How much do you want to spend?
on the conversion set, about 700 euro's, which is about $922

I want a front motor, not too big so its not very noticeable. A battery thats not too heavy. I want max speed of 35kmh with light peddling

I was looking at 8FUN-motor BPM (bafang) 350W motor with a panasonic 9,6a 36v battery, what I understood, these battery's are not as heavy.
That should be quite achievable then because you're relatively light and the roads are flat.The BPM needs 20 amps or more, which is too much for a 36v 10 aH battery. There are 8.8aH bottle batteries with Samsung 22P cells that can do it, but I've only seen them as OEM, which brings me to a suggestion. The Oxydrive kit will do 40km/h. It's really nice looking, especially if you choose the right colour bike to go with it. It has a bit more power than the Q100 and average Bafang 250w kits.
http://www.oxydrive.co.uk/

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Re: What component does what regarding speed limit?

Post by nosmo » Jun 15 2013 5:50am

How do brand motors do it? for instance, the new Bosch motor, is a 250/350W motor, has a 36V battery. There are dongles out there that can fool the Bosch motor, making you go 40kmh, instead of 25kmh. So that would suggest it would be possible with a 350W motor.

So the trick is finding the right motor (brand&type), finding the right controller and battery to go with it. Going faster will mean more needed Amps, so finding a battery that can deliver that is important and of course the controller should be able to handle those currents.

I will have a look at the Oxydrive, looking at the shop the prices are a bit more then my budget. I probably want to by a hybride bike, or buy a cheap second hand city bike and convert it to electric.

Bit confused about the different codes used by Bafang BPM, code 10 or code 11 would suit my needs. Are this really different types of motors, or same motor but different voltages are power usage?

And I learned that a aluminum fork is not as safe as a steel one, usually city bikes have steel, so should be ok there.

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Re: What component does what regarding speed limit?

Post by d8veh » Jun 16 2013 4:10am

The BPM Code numbers are probably the number of turns of wire around each pole of the motor, which has a direct effect on speed. The problem is finding a supplier that has the code number that you want. Most sell a high speed and a low speed one.The Code 10 or 11 would be right for your speed, but don't forget that these motors are a lot heavier, which is why they produce more power - then you need a bigger battery to provide the extra current and range. I don't think that you need a BPM because it's flat where you live.

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Re: What component does what regarding speed limit?

Post by nosmo » Jun 17 2013 12:06pm

hasnt anybody created an excel sheet with brand, motor, type, rpm, power, windings, maxspeed, etc?

People say 250W motors cant achieve 25+ km/h, but there are different professional brands that can do this at 36V.
Also increasing voltage can make your motor go faster, but isnt always the answer to more RPM.

So the search for the right motor continues... :) Thats what makes it fun right!

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Re: What component does what regarding speed limit?

Post by Drunkskunk » Jun 17 2013 12:50pm

There isn't a problem to get a 250w motor to run faster than 25kph. Simply feed it more voltage through an unrestricted controller, and it will go faster.

The problem is it's survival at those speeds. at 25kph you're pulling 250watts or so, and the motor is happy. at 35kph you're pulling closer to 400 watts, and the motor will overheat in time, But that may take a half hour at constant speed, depending on the motor and how it's used. Most people will see that as no real problem.
But as your speed increases, the time the motor can run before overheating decreases. At 50kph you'll be pulling around 1000 watts, which would melt many 250 watt motors in seconds.

The other problem is the gearing in the motors. it's designed to handle 250 watts. as you increase the power, you increase the likelyhood of the gears failing.
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Re: What component does what regarding speed limit?

Post by nosmo » Jun 17 2013 2:57pm

good points Drunkskunk, so now you're making me wonder what the difference is between a 250w motor vs a 500w version. Thicker wiring? More windings?

I still have to get into the whole windings, wire thickness, voltage and RPM radio.

Less windings = more rpm = more heat?

The challenge is to get a high RPM motor, with good enough torque, running at a low voltage.

But I did discover reading this forum, that the perfect motor is dependent on the total weight of bike+driver, landscape, pedaling yes/no. too bad there's isnt a wizard somewhere choosing the perfect combo :)

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Re: What component does what regarding speed limit?

Post by d8veh » Jun 18 2013 3:26am

As a general rule, the bigger the motor, the more power it can handle. The only two things you need to worry about are the RPM at nominal voltage, which you can change to the RPM you want by using a battery voltage higher or lower than the motor's nominal voltage, and the motor's power rating.

A 250w motor will probably be OK at 35 km/h for you because you're light and your journeys are flat. When the motor gets up to speed, the current goes down, so it's not really a problem to go fast. The problem would be if you used a fast motor struggling to get up a hill or in a very strong headwind.

The 350w and 500w Bafang motors are the same weight as each other, so there's no advantage with the 350w one. It's better to get the 500w one. These motors weigh nearly twice as much as the 250w ones, and like I said before, you need a heavier battery too. I think that a good 250w motor will be more suitable. The motors from MXUS and Dapu are half-way between, but I don't know anyone selling them on their own. I'll be testing a MXUS in a couple of weeks if you can wait for the result.

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Re: What component does what regarding speed limit?

Post by nosmo » Jun 18 2013 3:46am

hi d8vey, thank you for all the information, I am probably going for the oxydrive, sounds like a descent kit

and according to the seller
we never used Bafang motors on OXYDrive's. The speed mI quoted is 32mk/h on pure power (throttle only). If you pedal a bit you easily cover 35-38kmh depending on battery charge level
so thats the speed I am looking for. btw, 32kmh on throttle only is not bad.

Next step is to find out what type of bike to get, carbon front fork, or aluminum. Finding the right toque arm and finally figuring out how to build it on the bike. Hopefully the speed sensor wont be too big of a hassle to put on.

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