Help me understand what i just bought... Was i ripped off?

[DoubleM]

Hi,

My first post here and almost a newbie concerning bikes and ebikes.

Last time i ride a bike was like 15/20 years ago but recently i decided to buy an ebike so i started to google and i read a lot about them.

However i'm having some eventual issues what just i bought and i hope you can help me.

My choice went for an ebike from a company in my country that adapt kits on them. I decided for a 48v 500w rear hub motor and a 10.4Ah Samsung (told by the company) battery.

I avoided the 250w rear hub motors because i read they could struggle a bit in steepest hills and it was one thing i didn´t want. I wanted a bike with some hill climbing capacity. I knew a 500w motor will not do miracles but...

In every online simulator i run and every video i watched (and i watched a lot of them!) it seemed the 48v 500W motors fitted my needs.

However, in the first attemp to climb a steepest road (about 12%) near my home, with only the throttle, the bike stopped after a couple of meters. I started to pedal and in fact was a lot easier than a regular bike. I felt the PAS. And if i throttle i felt even more "power"( it's normal since i had the PAS in the max setting?).

Then i did some more tests. With the bike with the rear wheel in the air, it reaches around 45/46km/h (28mph) in the speedometer, however in the road, with my weight (about 80kg / 176lbs) is doesn´t run more than 34/35km/h (21mph). From what i see, these values seem to be from a "unlimited" 250w and not from a 500w.

In some roads with lower slopes (3/4%) it was able to run only with the throttle at speeds around 11 and 15km/h (7/9mph).

In the LCD the higher wattage i saw was like 550w. I think the motors usually reaches a higher wattage under load right? I saw some videos of 500w reaching 700/800w.

Moreover, the motor does a weird sound (at least at lower speeds) i don't know if it's normal or not but i made a movie throttling really slow so you know what i mean.

I confess i'm a little disappointed with it's lack of hill climbing. Maybe in fact it's a 250w instead of a 500w? Do you think these values are normal for a 48v 500w motor? I think something not right here.

I have no idea what the motor/controler are, they have no info at all. Maybe it's a chinese junk...

I know it´s hard to conclude but what do you think? Should i complain?

[youtube]P9u-LmhbGzc[/youtube]

 

[Sunder]

Not been able to watch the movie yet (on phone) but the speeds you describe are reasonable for 500w.

As for going over the 500w limit, there is no set "standard" for how this is implememted. For some 500w means 500w electrical at the battery. For others it means 500w kinetic measured on a dyno, for some it means "whatever I think will best sell on eBay".

500w disappoints most people who want a throttle, because it usually means they're not pedalling. You have a few options:

1. Ask if you can swap the controller for a bigger one. Your battery should cope to at least twice the size and the motor definitely will.

2. Mod the controller yourself.

 

[MadRhino]

Yep. 500w doesn't make a good climber. Double the power, feed it 1000w. The motor will run better when it doesn't risk stalling. A hub motor that stalls is transforming in heat all the current you feed it. The noise is probably the cogging of a motor that is struggling at very low efficiency speed.

 

[spinningmagnets]

That looks like it's a direct drive hub (not a geared hub)? Do you have a model number?

 

[DoubleM]

That looks like it's a direct drive hub (not a geared hub)? Do you have a model number?

Unfortunately i don't.

It seems they tried to cover all the traces in battery, controller, motor... Theres no model number in anything. It's a thing i wish to know too but i really don't know how.

Before i bought the bike i asked them and they told me they didn't know. Only thing i know is the LCD which is a SW900.

Speaking in LCD, one of the advanced menu options is the max amperage the controler delivers and it's 13. I'm not sure if it was the original value but if it wasn't 13 it was 12. I tried to change it to 15 but it was no better.

 

[dogman dan]

Its going to take a lot more than 15 amps to climb a 12% hill well. So you will have to pedal hard up that one.

Your performance sounds about right for the watts you have. But its also possible the wind of the motor is slower than typical. I suspect this because your top speed is a bit low for the wheel off the ground. Unloaded, it should be rotating faster at 48v.

Or,, the speedo is about 5 mph off. The chances of that are greater than the wind being slow. Check your display wheel size setting.

Oh, that's not a 250w motor, its a 500w rated DD motor for sure. To perk it up, feed it 1500w, not 750. But not with that battery.

 

[d8veh]

I'd say that you've got the wrong motor for what you want. You should have chosen a 500w geared motor, which would have given you all the climbing power you need when matched with the right controller.

The motor you have is much better suited to riding on the flat with a continuous speed of about 23 mph, provided that the controller gives enough power. It would work much better at 36v with much higher current than what you have now.

Your LCD shows the power from the battery. 550w seems very low. I would expect a controller of at least 18 amps at 48v, which would be 864w. You should see that any time you're accelerating with maximum throttle. A higher current controller would help with your problem, but your battery is limited to about 20 amps, but it won't last long if you run it at that.

People think that a 500w motor is going to be more powerful than a 250w one. In most cases that I've seen, especially if it involves hill-climbing, you'll get more power from a 250w one.

On our Pedelecs forum in the UK, a guy has been using a 1000w Cyclotricity bike for his regular commute. It has a similar kit to yours but probably runs higher current. He can't run it on maximum all the time because he wouldn't get to work before the battery runs out (range about 10 miles). He's just changed to an OEM 250w bike, which beat his best journey time significantly.

All things considered, if you're unsatisfied with the performance of your bike, I think the best option would be to change the motor to something like a Bafang BPM or Q128H, but you have to choose a motor that gives the right speed. 260 RPM would give you cruising in the 20-25mph range. To get more current, you need a controller and battery, which would be more expensive.

The grating noise that you're getting at low speed is common, but you might be able to do something about it if you have a KT controller. Show us a picture of your LCD to confirm that. There's a parameter in the settings that you can change to get better synchronisation between the controller and motor.

 

[spinningmagnets]

At low power, a geared hub allows the motor to spin five times for every wheel rotation. This multiplies the torque so that a 250W geared motor can climb a little better than a 500W direct drive hubmotor. The place where the direct drive shines is when you apply high power (48V X 30A = 1440 watts). The geared hubmotors have a poor heat-shedding path, so they can get overheated at high amps.

A direct drive has more copper mass, so it can absorb and shed heat better than a geared hub. If you ever upgrade to a high-volt / high-amp battery and controller, then that is what will really "wake up" the motor you have. The kit as you have it right now (36V / 15A?) is only useful on flat ground.

 

[neptronix]

That motor can produce more power and more hill climbing ability with more amps applied.
The question is.. can the battery handle those amps under load?

What you bought was a kit that wasn't specced out for your needs. You didn't get the right information from the vendor, or maybe didn't know what you were looking for. Chalk it up to a learning experience.

http://www.ebikes.ca/tools/simulator.html

Go play with this motor simulator for a bit.. it can be really helpful in determining how much power you need.. how different motors perform in different situations.. etc. Great learning tool.

 

[rumme]

Ive built ebikes with direct drive hub motors and geared hub motors. I think the geared hub motor isn't worth it. They can be noisy, they have more parts to break, and they seem to generate ALOT of heat . The bafang 750 watt nominal geared hub motor I tried, was GARBAGE....my cheap direct drive 1000 watt yescomusa hub motor performed better and it was less expensive .

 

[DoubleM]

Your LCD shows the power from the battery. 550w seems very low. I would expect a controller of at least 18 amps at 48v, which would be 864w. You should see that any time you're accelerating with maximum throttle. A higher current controller would help with your problem, but your battery is limited to about 20 amps, but it won't last long if you run it at that.

I searched online for the LCD options and theres one setting for: "The Current-limiting of Controller. The original Current is 12A. Range:1-20A".

However i don't know if it's safe or even theres any advantage in changing it. Lets suppose the controller is in fact 12A. If i change that setting for 20A, what could happen? I only tried once at 15 but i didn´t feel any change in the performance (but i admit it was a quick test).

The grating noise that you're getting at low speed is common, but you might be able to do something about it if you have a KT controller. Show us a picture of your LCD to confirm that. There's a parameter in the settings that you can change to get better synchronisation between the controller and motor.

The LCD is this one (or at least a close one. Mine has 17 parameters). Theres a list of the advanced options in page 4.

http://www.boatstogo.com/images/Saturn-Electric-Folding-Bicycle/LCD-Instructions-SW900.pdf

 

[d8veh]

Set the current to 18 amps. Your battery dhould be OK with that. 18 amps will give 50% more torque, but your range will decrease proportionally.

I don't know what these guys are doing with their geared hub-motors, but I have many many thousands of miles on just about all the different ones you can get and I've never had a problem with heat because they run so much more efficiently. Also, the Q128c that I use at the moment is absolutely silent at all speeds. It's much quieter than any DD motor that I've ever heard. It doesn't even hum.

 

[rumme]

Set the current to 18 amps. Your battery dhould be OK with that. 18 amps will give 50% more torque, but your range will decrease proportionally.

I don't know what these guys are doing with their geared hub-motors, but I have many many thousands of miles on just about all the different ones you can get and I've never had a problem with heat because they run so much more efficiently. Also, the Q128c that I use at the moment is absolutely silent at all speeds. It's much quieter than any DD motor that I've ever heard. It doesn't even hum.

I weigh 240 lbs and have hilly roads . My bafang 750- watt was extremely dissapointing in both torque and speed. The only positive aspect was the freewheeling function. I sold it and think a well designed efficient direct drive hub motor is a better choice.

 

[neptronix]

Ive built ebikes with direct drive hub motors and geared hub motors. I think the geared hub motor isn't worth it. They can be noisy, they have more parts to break, and they seem to generate ALOT of heat . The bafang 750 watt nominal geared hub motor I tried, was GARBAGE....my cheap direct drive 1000 watt yescomusa hub motor performed better and it was less expensive .

Yeah, you haven't tried many geared motors, have you?

I have a geared motor that produces less heat per watt inputted than your thick lamination yescom produces. Any guess as to which motor i'm talking about?

Again, the ebikes.ca simulator proves what's good and what aint..

 

[rumme]

Ive built ebikes with direct drive hub motors and geared hub motors. I think the geared hub motor isn't worth it. They can be noisy, they have more parts to break, and they seem to generate ALOT of heat . The bafang 750 watt nominal geared hub motor I tried, was GARBAGE....my cheap direct drive 1000 watt yescomusa hub motor performed better and it was less expensive .

Yeah, you haven't tried many geared motors, have you?

I have a geared motor that produces less heat per watt inputted than your thick lamination yescom produces. Any guess as to which motor i'm talking about?

Again, the ebikes.ca simulator proves what's good and what aint..

I tried the bafang, which is supposed to be a name brand geared motor , and I thought it performed poorly.

Yes, the online ebike calculators are nice, to a certain extent, but in real world use, they often are very misleading. A persons body weight, hill conditions , outside temperature, etc can greatly change online calculation estimates. Kinda like how online poker simulations often do not equal LIVE poker situations.

 

[neptronix]

I tried the bafang, which is supposed to be a name brand geared motor , and I thought it performed poorly.

It's a huge error to think that a product is good or bad based on the brand name associated with it. Even worse to believe third party reseller specs, especially when they don't provide dyno graphs. Marketing and specifications rarely line up.

Yes, the online ebike calculators are nice, to a certain extent, but in real world use, they often are very misleading. A persons body weight, hill conditions , outside temperature, etc can greatly change online calculation estimates. Kinda like how online poker simulations often do not equal LIVE poker situations.

You can enter your weight, hill conditions, battery voltage, vehicle weight, motor, controller, battery size etc into this simulator and it is actually rather accurate. I have found it to be +/- 5% accurate. I get a better approximation of what is going to occur from using it versus not using it

With some external tools you can also model aerodynamics.

 

[DoubleM]

Set the current to 18 amps. Your battery dhould be OK with that. 18 amps will give 50% more torque, but your range will decrease proportionally.

I´ll try that. It will output 18 amps even the controller is rated to a lower value, forcing it? Or it will only work if the controller is 18 amps or more?

 

[rumme]

I tried the bafang, which is supposed to be a name brand geared motor , and I thought it performed poorly.

It's a huge error to think that a product is good or bad based on the brand name associated with it. Even worse to believe third party reseller specs, especially when they don't provide dyno graphs. Marketing and specifications rarely line up.

Yes, the online ebike calculators are nice, to a certain extent, but in real world use, they often are very misleading. A persons body weight, hill conditions , outside temperature, etc can greatly change online calculation estimates. Kinda like how online poker simulations often do not equal LIVE poker situations.

You can enter your weight, hill conditions, battery voltage, vehicle weight, motor, controller, battery size etc into this simulator and it is actually rather accurate. I have found it to be +/- 5% accurate. I get a better approximation of what is going to occur from using it versus not using it

With some external tools you can also model aerodynamics.

Yes..but as you mentioned, aerodynamics is also a big factor . I weigh 240 lbs and have 54" chest and 18" arms. My build is definitely not conducive to good
aerodynamics on a ebike...and its these types of factors that can cause big variations from real world riding to online ebike calculators. Then you have other factors, such as my area is VERY windy.

 

[neptronix]

Yes..but as you mentioned, aerodynamics is also a big factor . I weigh 240 lbs and have 54" chest and 18" arms. My build is definitely not conducive to good
aerodynamics on a ebike...and its these types of factors that can cause big variations from real world riding to online ebike calculators. Then you have other factors, such as my area is VERY windy.

So what other method do you use to simulate motor torque, distance, etc so that you can get a ballpark idea of how a given configuration to perform? do you read dyno graphs before buying a motor? how is your method better than mine?

I started out this hobby when i was 270lbs. Now 172lbs.. my cruising wattage is not vastly different though. The main problem with a bike is the shape of what is moving through the air. The simulator i mentioned has helped me find the best motor for what i'm trying to build regardless. I can assume fat me and skinny me use +/- 100 watts and generally be right on that in the real world while looking at what the cycle analyst or turnigy watt meter is displaying.

 

[ScooterMan101]

This , Plus I will add to this but first
...
Can you return the kit back to the person who sold it to you and get your money back ?

I will add , a couple of the newer ( geared ) hub motors have thermal cut off features when combining the right parts ( Motor and Controller and Display ) bought from the same vendor.

For Example there is a newer version ( Luna's ) version of the Xiondga 2 speed hub motor .
However for more power that that one
The New Mac motor that EM3ev.com sells. When combined with the Infineon Controller and New Cycle Analyst V3/V3.1 it will also have a thermal shut off function so that you can go up steep hills and the controller/display will shut off the motor before it gets too hot to do any damage, in other words it saves the motor.
With these two Geared Hub Motor kits you can now run a Hub Motor up hills.

The main difference between the two is that the Mac Motor is more powerful.
( better hill climbing ability when using 25 amps or more, and is faster )

For the Mac Motor you will want a Battery that can put out 25-30 amps .

If you have to keep the Battery and it is a low grade/cheep cells battery , and ,
you do not need to go faster then the Luna's Xiondga Kit would work.

If you get the Mac, and you live in an area that has 12% + slope hills , get the 12T Mac Motor and put it into a 26 inch wheel.
If you have hills that only go up to 6% slope the 6T-10T will work find in a 26 inch rear wheel.

At low power, a geared hub allows the motor to spin five times for every wheel rotation. This multiplies the torque so that a 250W geared motor can climb a little better than a 500W direct drive hubmotor. The place where the direct drive shines is when you apply high power (48V X 30A = 1440 watts). The geared hubmotors have a poor heat-shedding path, so they can get overheated at high amps.

A direct drive has more copper mass, so it can absorb and shed heat better than a geared hub. If you ever upgrade to a high-volt / high-amp battery and controller, then that is what will really "wake up" the motor you have. The kit as you have it right now (36V / 15A?) is only useful on flat ground.

 

[rumme]

Yes..but as you mentioned, aerodynamics is also a big factor . I weigh 240 lbs and have 54" chest and 18" arms. My build is definitely not conducive to good
aerodynamics on a ebike...and its these types of factors that can cause big variations from real world riding to online ebike calculators. Then you have other factors, such as my area is VERY windy.

So what other method do you use to simulate motor torque, distance, etc so that you can get a ballpark idea of how a given configuration to perform? do you read dyno graphs before buying a motor? how is your method better than mine?

I started out this hobby when i was 270lbs. Now 172lbs.. my cruising wattage is not vastly different though. The main problem with a bike is the shape of what is moving through the air. The simulator i mentioned has helped me find the best motor for what i'm trying to build regardless. I can assume fat me and skinny me use +/- 100 watts and generally be right on that in the real world while looking at what the cycle analyst or turnigy watt meter is displaying.

Um...I never claimed I have a better method then you use. I claimed the method of using online calculators will not always equal real world scenarios. This conversation was never about me having a better method then you or anyone else.

Congratulations on all the weight you lost. Low carb diet ?

 

[neptronix]

Um...I never claimed I have a better method then you use. I claimed the method of using online calculators will not always equal real world scenarios. This conversation was never about me having a better method then you or anyone else.

Congratulations on all the weight you lost. Low carb diet ?

I know you never claimed it, it was more of a prod to say.. hey.. do some calculations.. and if you think my method is inadequate.. let's see a better way to do it

Yeah, low carb. I started the diet 4 years ago, lost it all, and stuck to the diet because it just became a way of life.
I tried everything else before to no success.

 

[rumme]

Um...I never claimed I have a better method then you use. I claimed the method of using online calculators will not always equal real world scenarios. This conversation was never about me having a better method then you or anyone else.

Congratulations on all the weight you lost. Low carb diet ?

I know you never claimed it, it was more of a prod to say.. hey.. do some calculations.. and if you think my method is inadequate.. let's see a better way to do it

Yeah, low carb. I started the diet 4 years ago, lost it all, and stuck to the diet because it just became a way of life.
I tried everything else before to no success.

Good for you ! I do the same lifestyle of low carb , but I am a bodybuilder . I believe sugar is the biggest enemy in the diet of Americans. As you know, losing the weight is not as hard as keeping it off . I can stay away from most of the sugar products, but anything with potatoes , is my weak point. The other major factor is drinking water .

 

[rumme]

Um...I never claimed I have a better method then you use. I claimed the method of using online calculators will not always equal real world scenarios. This conversation was never about me having a better method then you or anyone else.

Congratulations on all the weight you lost. Low carb diet ?

Yeah, low carb. I started the diet 4 years ago, lost it all, and stuck to the diet because it just became a way of life.
I tried everything else before to no success.

Its kinda funny, but I play in some local poker games, and everyone at the table is so out of shape . They often start asking me questions about my eating habits and they insinuate they want to do it ...so they will go low carb for about a week or two, then start right back into the bad habits of drinking soda pop, eating twinkies, etc. One of the main traits the human race is lacking on, is discipline.

 

[999zip999]

I say you want a 1,500 watt controller 25 or 30amp and proper battery for it. You can use a 750w motor for 2,000 watts. It's all about a good battery the heart of a an electric bike. Yes it's the battery.