2 Speed Xiongda hubmotor

[Alan B]

Normally you might have to choose top speed and hill climbing in a compromise. With this motor you get the 1.8:1 two speeds to help with that. So you can choose winding/wheel size for a top speed on level pavement, and use the low gear for climbing.

Mid drives are nice, with lots of gear choices. But the useful range seems to be limited to less than 3:1. You can get a little over 3:1 if you use an 11-36 or wider gearset, but realistically the USA power level mid drives don't need that wide a range. With my BBSHD I don't need to use the lowest couple of gears, and for decent chain life one should not go much below 14 teeth, so the range needed seems to be less than 2:1.

So the Xiongda is rather like having the highest and lowest useful gears of a mid drive.

 

[bigoilbob]

"Several message indicate that to get higher speed one should order a motor with specified smaller wheel size."

I think you got it versa visa. Please point us to these posts. If a motor winds out at ONE given r/m, ~260-270 in the case of ALL X motors, I believe, then the ONLY way to INCREASE top speed (and thereby DECREASE hill climbing power) for a given motor, is to lace to a bigger wheel..

We seem to have a misunderstanding and I am not going back to chase down the messages again. Perhaps an example would be appropriate.
"... to get higher speed one should order a motor with specified smaller wheel size."
If one wants a higher speed motor for a bicycle with 700C wheels then one should order a motor for a 24 or 26 wheel size.

We don't order hubs "for wheel size". We figure out our needs (hill climbing ability, speed), look at the wheel size(s) that will fit our build, look at any lacing limitations, and back calc the hub that best meets those needs. And while a given hub might not be able to power you to a proportionately higher speed for a given increase in radius between the axle center and rubber on the road, unless you are so underpowered that you'll stall out at a LOWER top speed with a larger referenced radius, we NEVER assume that a "smaller wheel size" will INCREASE top speed....

 

[bigoilbob]

"Several message indicate that to get higher speed one should order a motor with specified smaller wheel size."

I think you got it versa visa. Please point us to these posts. If a motor winds out at ONE given r/m, ~260-270 in the case of ALL X motors, I believe, then the ONLY way to INCREASE top speed (and thereby DECREASE hill climbing power) for a given motor, is to lace to a bigger wheel.

Anyone who can demo one of those X tables showing that different motors of theirs (whether wider or thinner or higher or lower voltages) have differing max radial velocities, please post. Actually, I'm surprised that all of them I've seen DO have the same max radial velocity, and I might very well be making an observational mistake. Feel free to smarten me up some......

I have a motor that I ordered for a 20" wheel that has been gathering dust since I bought it about 2 years ago, as I have never laced a wheel with it. Normally the RPM should be higher than 270 because it would run too slow otherwise.
I am getting really curious to know the RPM now, I will try to find some time to test it asap.

Many thanks for your observation. I back calc'd my max "effective" (i.e. provides some torque) r/m for my motor, and it is ~315 r/m instead of the ~270 reported by Bonnie. Now, that is at ~52 volts, and it drops down some by the time I get to 47-48 volts. But you are sure on the right track. But concurrently, you can ask Bonnie for your performance table, and compare it. FYI, with my 16" wheel. I am still drawing amps at ~15 m/h, fully charged, and if your load is small enough you should be able to beat that by ~25% (with the 48 volt motor). G'luck!

 

[knutselmaaster]

We don't order hubs "for wheel size".

In fact, I do order for wheel size. But as stated, I'm not yet sure if there is a difference.
I do know that if an order is big enough, I can demand a programmed max speed on the KT controller. (yes, of course I understand that this has nothing to do with the rpm of the motor itself)

Edit; from an efficiency point of view, and keeping in mind the legal speed limit, the best is to have a motor that has a max rpm at about 15% above the speed limit. This way, as most electric motors are the most efficient around 85% of their max rpm, the losses are low at high speed. (we have a 25km/h max speed here in Europe and thus are relatively often running at that speed as it is easily attainable and a comfortable cruising speed)

 

[bigoilbob]

We don't order hubs "for wheel size".

In fact, I do order for wheel size. But as stated, I'm not yet sure if there is a difference.
I do know that if an order is big enough, I can demand a programmed max speed on the KT controller. (yes, of course I understand that this has nothing to do with the rpm of the motor itself)

Edit; from an efficiency point of view, and keeping in mind the legal speed limit, the best is to have a motor that has a max rpm at about 15% above the speed limit. This way, as most electric motors are the most efficient around 85% of their max rpm, the losses are low at high speed. (we have a 25km/h max speed here in Europe and thus are relatively often running at that speed as it is easily attainable and a comfortable cruising speed)

"...the best is to have a motor that has a max rpm at about 15% above the speed limit." "The best" is to design your install to best meet your needs, "the speed limit" being only one of several parameters. For example, in stop and go riding, only a fraction of your power will be applied at ~85% of max r/m, most of the time, with most hubs. Pretty much blowing that "efficiency" out of the water. FYI, the increase in "sweet spot" use fraction is one of the advantages of a 2 speed hub.

Here was MY view, on MY build. I wanted efficiency, hill climbing power for 2, and speeds low enough to be safe with a tandem recumbent. So, my 16", 48 volt, Xiongda, 2 speed front hub can only make ~15 m/h, but is ideal for us. It can take us up hills and we can tour towns and villages on vacation. We can also use it for 85% of our urban commuting needs in south St. Louis, Mo., USA. If you want to go faster, farther (and your needs to do so are only for you to judge), spend the extra hundreds/thousands to do so, SAFELY. The name of the game is to match your actual requirements, of which "speed limit" is only one piece of many.....

 

[knutselmaaster]

Yes, indeed you're right.
With the 2 speed motor and European max speed, the efficiency is very good with what I stated above though. Even in start stop situations, you don't stop every few meters. I cannot imagine a motor rpm more efficient than "~25km/h = ~85% of max rpm". Even if you never reach 25km/h (like in extreme start/stop situations), the low gear will take you to about 17km/h and the high gear will function as an overdrive for the moments that you go a bit faster than 17km/h, making it run above 60% of the max rpm, at least. (Which definitely is not fast on an ebike by the way, I don't even go that slow on a normal bike)
Of course one can imagine usages and situations that make that this doesn't apply but generally speaking it just fits about every bike and situation.

If the legal max speed is much higher, one should think a bit more about what the usage of the bike will be as you'll loose torque if the max rpm gets higher, a compromise based on rider and circumstances should be found.
The motor reaches 25km/h so easily, while the torque in low gear remains sufficient, that that compromise isn't needed here, you'll always have torque and speed enough.

 

[Lost]

Exchange automatic shifting for a color screen is not what I would do.

So the Luna version does not have the automatic shifting? Does it do the PAS?

Thinking more and more of a DD.....

 

[markz]

Yes Direct Drive is much better, go with dd.

 

[Alan B]

The Luna version has manual shifting, and it comes with a PAS sensor.

Luna has paired the motor with a different controller and display than the factory. The Luna display has some diagnostic features that could be helpful if there are any problems.

I haven't installed it yet, so don't have any operational comments.

It came well packed. The rim brake style front motor, mounted in a 20 inch rim, including the cable and spokes, (without rim tape, tube or tire) weighs 139 ounces.

This is a sample provided for evaluation.

It will be a couple of weeks till I get to the testing.

 

[2old]

Deleted; sorry.

 

[slacker]

according to luna's website 6.5 pound's.

 

[2old]

Deleted; my brain is mush.

 

[dustNbone]

Isn't there 16oz in an lb? That would make 139/16=8.6875

 

[markz]

454 grams, 16oz, 2.2kg in a pound

 

[Alan B]

454 grams, 16oz, 2.2kg in a pound

2.2kg in a pound??

 

[knutselmaaster]

As you can see on the previous page of this topic, the bare motor ways 3,45kg.
http://lmgtfy.com/?q=Convert+3.45+kg+to+lbs
The motor in the wheel ways 139oz
http://lmgtfy.com/?q=Convert+139+oz+to+lbs

Which makes a difference of 1.1 lbs (rim+spokes+nipples)

 

[Alan B]

As you can see on the previous page of this topic, the bare motor ways 3,45kg.
http://lmgtfy.com/?q=Convert+3.45+kg+to+lbs
The motor in the wheel ways 139oz
http://lmgtfy.com/?q=Convert+139+oz+to+lbs

There are many variants of this motor, so the weight changes a bit with each one. Since this wheel came pre-built I didn't have an opportunity to measure the bare (front, non-disc brake) motor. Anytime people are quoting weights or widths they should also state the variant to keep the data useful.

 

[knutselmaaster]

Yes indeed, the front and rear wheel version are quite different in size and shape. It mostly is the aluminum casing that changes though (which has a small influence on total weight), as the internals should be quite similar. As copper windings and magnets give the power (which is similar throughout all versions), and make the largest part of the total weight, the weight difference between the front and rear models (disk/no disk) shouldn't be more than a few percent though. Maybe 10-15% at most...

 

[Alan B]

Yes indeed, the front and rear wheel version are quite different in size and shape. It mostly is the aluminum casing that changes, as the internals should be quite similar. As copper windings and magnets give the power (which is similar throughout all versions), and make the largest part of the total weight, the weight difference between the front and rear models (disk/no disk) shouldn't be more than a few percent though. Maybe 10-15% at most...

I would agree that the differences should be relatively small. However one purpose of review is to post data and avoid speculation where practical.

 

[robocam]

So you have the Luna version? How is it? Have you had a chance to test it yet? =)

Does anyone know how it compares to a gearless hub motor? Let's say we're talking about the same voltage (52V). How many amps would I have to send that motor for it to have the same amount of torque as the Xiongda in 1st gear? I'm trying to find a good hill climbing hub motor (20" wheel) for my trailer. I wonder how much force it can push my trailer with. I don't want something that has so much torque it just spins the wheel. My trailer will have around 100 lbs in it.

So far on my list I have the Xiongda and Ebike Kit units from Luna and this one on Amazon (and eBay). I'm drawn to the lower price. 26A isn't bad though. Is there a significant difference in torque between 36V and 48/52V (at around 5 to 10 mph)?

https://smile.amazon.com/gp/product/B01C6QZ2US

The Luna version has manual shifting, and it comes with a PAS sensor.

Luna has paired the motor with a different controller and display than the factory. The Luna display has some diagnostic features that could be helpful if there are any problems.

I haven't installed it yet, so don't have any operational comments.

It came well packed. The rim brake style front motor, mounted in a 20 inch rim, including the cable and spokes, (without rim tape, tube or tire) weighs 139 ounces.

This is a sample provided for evaluation.

It will be a couple of weeks till I get to the testing.

 

[robocam]

How would I activate the regen braking? Do I just short the brake connector on the controller?

The regen braking from the Amazon kit would be nice on a trailer. When I'm pulling 40 lbs with mid-drive trailer it takes a fair bit longer to stop-- enough that it is disconcerting when switching from a regen capable setup. In a small 20" wheel it should work well with that weight. The Xiongda setup is lower power, but if you like lower speed setups and have steep hills it might perform well.

Any updates on the kit Luna sent you, Alan?

 

[Alan B]

So you have the Luna version? How is it? Have you had a chance to test it yet? =)

Does anyone know how it compares to a gearless hub motor? Let's say we're talking about the same voltage (52V). How many amps would I have to send that motor for it to have the same amount of torque as the Xiongda in 1st gear? I'm trying to find a good hill climbing hub motor (20" wheel) for my trailer. I wonder how much force it can push my trailer with. I don't want something that has so much torque it just spins the wheel. My trailer will have around 100 lbs in it.

So far on my list I have the Xiongda and Ebike Kit units from Luna and this one on Amazon (and eBay). I'm drawn to the lower price. 26A isn't bad though. Is there a significant difference in torque between 36V and 48/52V (at around 5 to 10 mph)?

https://smile.amazon.com/gp/product/B01C6QZ2US

The Luna version has manual shifting, and it comes with a PAS sensor.

Luna has paired the motor with a different controller and display than the factory. The Luna display has some diagnostic features that could be helpful if there are any problems.

I haven't installed it yet, so don't have any operational comments.

It came well packed. The rim brake style front motor, mounted in a 20 inch rim, including the cable and spokes, (without rim tape, tube or tire) weighs 139 ounces.

This is a sample provided for evaluation.

It will be a couple of weeks till I get to the testing.

My ebike projects have all been placed on hold due to other demands on my time combined with poor weather and storm damage here in California. I don't ebike in wet weather, and it has been extremely wet this winter. The test motor is packed back in the box waiting. I did take some photos of this motor kit when I received it:

https://goo.gl/photos/AQLKjVJR2VocPWoDA Photo Album for the Two Speed Motor Ebike Project

I was planning to install the test motor wheel on my mid drive folding ebike, I think I will instead procure a second bike to put it on. I want to have a pair of folding bikes for various uses including camping, and I don't want the two projects interfering with each other. I should be ordering the second bike soon. The weather pattern is improving, lately it has been teasing us with a few days of dry weather, and then another storm passes through. There are a lot of slides blocking the bike lanes, water is still seeping out of the hillsides making unsafe conditions in the bike lanes, and my favorite bike loop has a bridge out. The infrastructure will take a long time to recover. I have been enjoying an electric Leaf in this weather.

While I haven't tried this motor yet, I do have a bike with a DD rear and a geared front hubmotor that provides an interesting platform for comparing the two motor types. The geared motor produces a lot more low speed torque for the same current than the DD motor. I expect this two speed motor (in low gear) to produce even more low speed torque than a standard geared hubmotor. The speed will be reduced of course, but the weight of the small two speed motor is lower than the larger geared or DD hubmotors, and the torque produced per amp is higher. I have experienced this on the all wheel drive Ebike that a lot more current and power is required in the rear DD motor to have similar torque to the front geared motor.

Most users are annoyed by the unpowered cogging resistance of DD motors compared to the zero resistance coasting of geared motors, however that is to be traded off with the potential of regen / electric braking that DD motors provide. The usual cheap controllers have poor regen / ebrake control, it requires an expensive sinewave controller to get good braking control (variable, etc).

 

[ScooterMan101]

You got a front version ?

I and many others are looking for reports on the testing on the rear 2 speed hub motor .

For instance the rear needs a frame with 143 mm drop out spacing ?

If so that would work with modern bikes that have the rear , through axle design. With of course custom made plates for both sides of the frame to be able to use a bolt on axle.

Luna has paired the motor with a different controller and display than the factory. The Luna display has some diagnostic features that could be helpful if there are any problems.

I haven't installed it yet, so don't have any operational comments.

It came well packed. The rim brake style front motor, mounted in a 20 inch rim, including the cable and spokes, (without rim tape, tube or tire) weighs 139 ounces.

This is a sample provided for evaluation.

I was planning to install the test motor wheel on my mid drive folding ebike, I think I will instead procure a second bike to put it on. I should be ordering the second bike soon. T

 

[robocam]

Thanks for that comparison. Do you think the Luna 2-speed hub motor at 52V/20A will have more torque than a DD at 52V/40A (at around maybe 5-10 mph)?

Could I just short the phase wires together as an electric brake on a DD? I don't really need anything fancy for my trailer because I will only activate its brakes when the ones on my bike can't slow it down enough. This seems like it would be much easier than trying to implement surge brakes. I'd have to find a way to mount brakes on both wheels and then come up with a way for the cable to be pulled when I slow down. With a DD, all I'd have to do is press a button.

...The usual cheap controllers have poor regen / ebrake control, it requires an expensive sinewave controller to get good braking control (variable, etc).

 

[knutselmaaster]

XiongDa claims 70Nm of torque in low gear.