2 Speed Xiongda hubmotor

[docnjoj]

Here are some pictures of the Xiongda 2 speed on my trike after the first road test. The trusty 9C is also shown. the shifter makes the handlebars a bit crowded, but manageable. Now if I can only get the automatic shift to work............ Thi trike seems to have good power up a 5% hill in low gear as long as I use the shift button. In auto mode it hunts and pecks, even on a hill. There are four different controls on that one handlebar, so it gets kind of busy. I had to change my 7 speed rear gears for a 5 speed. Should be fine as the highest gears are rarely used at the speeds we travel.
otherDoc

 

[eMax]

I hope you gave the wheel-builder the frame so that he can get the rim central. It needs an off-set if it's a rear motor. Ideally, you need the gears on and all the spacers in place, for him to get it right.

Thanks for the info! Have passed on the info to my wheel builder who definitely has the capacity to set up the offset. The frame is a steel one so should be a bit of room to move also. We will see.

 

[drsolly]

This is great news! My wheel is currently being built now and plan to do some good testing over the weekend. The efficiency seems good. Sorry if I missed something but what bike are you running this motor in?

A Haro 26 inch folder, front and back suspension

 

[drsolly]

How does it compare to your other motors?

In low gear, it's slightly less torque than a 500w motor (but only slightly), and in high gear it's slightly less speed (but only slightly). My use of the bike doesn't need speed, going over rough ground I'm very happy with 10 mph (and this will do 12). On tarmac, if I'm heading back to the car and not stopping every 200m for a cache, then speed is useful, but I'm happy with 15 mph.

 

[cwah]

but for a trike, is 2kg difference that important? why not just get a bpm?

 

[docnjoj]

How does it compare to your other motors?

In low gear, it's slightly less torque than a 500w motor (but only slightly), and in high gear it's slightly less speed (but only slightly). My use of the bike doesn't need speed, going over rough ground I'm very happy with 10 mph (and this will do 12). On tarmac, if I'm heading back to the car and not stopping every 200m for a cache, then speed is useful, but I'm happy with 15 mph.

Those are similar speeds that we use also. I can't go faster than 15 or so on our MUT because of dog walkers, runners and hotel guests on rental bikes.We pick time when there are few of those problems but still.........Anyways another road test today.
otherDoc
@cwah
I have had Bafangs but they were quite noisy, which to me is a no-no. This motor is quiet, so far. Don't need the power or speed of the larger motors.

 

[docnjoj]

Well I just got back from about 4 miles of testing and more bad news. The auto is quite useless as it hunts even on a 4% hill going up. The motor is really slow but can use high gear for starts on level ground. Since there were no markings or stickers on it, I'm afraid I must conclude that it is the regular wind and not the fast wind that I ordered. I only have 36 volts. As a science experiment, this is interesting, but as a usable motor, not so much. Does anyone know how I can tell what wind I have? I will open the motor if I need to.
otherDoc

 

[rj7855]

That it "hunts" going uphill was/is completely expected IMHO, switching gears is done by changing the motor direction ; I guess that takes a couple of seconds and during that time the motor does not provide any power to the wheel and your bike will slow down to below the lower threshold. I don't see really the point complaining about that; it's the same in my 24k € car shifting automatically to second gear on the ramp of my parking garage only to get almost completely stalled and shifting back to first. That'd why you can (both my car as this motor) lock it preventing it from shifting up.

 

[Jonathan in Hiram]

Does anyone know how I can tell what wind I have? I will open the motor if I need to.
otherDoc

No load RPM @ voltage @ low and high gear should do it, if you have a speedo on the wheel you can work backwards from mph to rpm.

Otherwise if you have a video capable camera and you know the frame rate you can put a mark on the wheel and count the frames it takes to make a revolution (or five or ten)as you step through the video one frame at a time and work backwards from that to get rpm.

For instance if you have a video at 30 fps and it takes the wheel say six frames to make one revolution then it's turning 30/6 or 5 times per second which is 5*60 or 300 rpm.

From everything I gather reading the threads and from the manufacturers specs I have managed to get via email I think it takes 48V to run 20 mph-ish on a 20" wheel in high in high gear with one of the fast wind motors.

Since my bent has 20" front and 26" rear wheels I'm considering getting a fast wind rear motor @48V 15A and lace it into a 26" rim, my drag is low enough I think that would work on the flat without overloading the motor and still have enough climbing ability in low to go up my rolling but not ultra steep hills.

 

[docnjoj]

Thanks, Jonathan. I may give that a try as it is the easiest way to compare this motor with others. Judging from what you say, it still could be the fast wind, but the wattmeter in the screen show lower wattage than I am used to. We shall see. It could be efficiency?
otherDoc

 

[endlessly_ending]

Thanks, Jonathan. I may give that a try as it is the easiest way to compare this motor with others. Judging from what you say, it still could be the fast wind, but the wattmeter in the screen show lower wattage than I am used to. We shall see. It could be efficiency?
otherDoc

How much of a difference do you see and to what motors are you comparing to?
I was pleased by the high efficiency when runnung uphill in low gear.
I compared against a geard 250W MXUS from Xin Feng of roughly the same size and weight, that I like very much.
http://www.mxusebikekit.com/shop_show.asp?cid=52

The motor becomes way less hot and thus for the time being I do not further consider to test ATF cooling with the XiongDa two speed hub

 

[docnjoj]

Well here is the bad news.

Suppose that a vehicle has a speed of m miles per hour.

m miles 5,280 feet 12 inches 1 hour (5,280)(12)(m)in.
------- x ---------- x --------- x -------- = ------------------ =
hour mile foot 60 min. 60 min.

1,056m inches per minute.
(the formatting does not hold up for the divisors

So, if you divide that by the circumference of the circle, you will
have the rpm's.

Measured MPH free running
Low=10 mph=168rpm possibly lower
High=18mph=201rpm possibly lower
All free running wheel off the ground for a 20” Wheel with tire measured diameter 20”
These are with a freshly charged battery.
This sure looks like a regular speed motor, not the high speed that I ordered, to me. On the other hand, the graph looks quite similar for high speed???????
Comments welcome since I could be completely wrong.
otherDoc

 

[docnjoj]

Thanks, Jonathan. I may give that a try as it is the easiest way to compare this motor with others. Judging from what you say, it still could be the fast wind, but the wattmeter in the screen show lower wattage than I am used to. We shall see. It could be efficiency?
otherDoc

How much of a difference do you see and to what motors are you comparing to?
I was pleased by the high efficiency when runnung uphill in low gear.
I compared against a geard 250W MXUS from Xin Feng of roughly the same size and weight, that I like very much.
http://www.mxusebikekit.com/shop_show.asp?cid=52

The motor becomes way less hot and thus for the time being I do not further consider to test ATF cooling with the XiongDa two speed hub

Well with a 20" wheel I should be able to get to 12 mph in low gear and maybe 20 or so in high. I like what looks like efficiency but don't really need it with a 20 ah pack. I could use a bit more speed and really need the auto shift. Don't forget my numbers are free running, not with the wheel on the ground with me on the trike. We're talking slow.

otherDoc

 

[panurge]

Hello Doc.
Sad that you have problems with the motor....
With My 20" motor (used on a 22.5+" tires), I get 18Kph in low and 32Kph in high at 37v (9s lipo fresh of charge...) obviously a bit more with 10s, loaded....since your tire is 2.5" smaller or so than mine, you should get a -4kph or so compared to my speeds, but since you use it at a slightly higher voltage (10% or so) the total speed result, shouldn't be that different....
From these raw calculations the 26" wind motor should go 22kph (9s) or 24kph (10s) in high on a regular 20" tire....

About the autoshift....even if theorically the Speed+Amp logic of the KTs seems the best way to go, in the actual real world I'm much more happy with the fixed shift point of the lishui controller. It shift at 15kph and downshift at 12Kph.....without any problem. You know it and in normal circumstances works perfectly, and anyway you may intervent manually if the speed in a commuting segment floats over and under the shifting speed. Also, seems to me that the lishui shifting is faster than the KT (squared) but I have to better compare the two bikes since the 700c is built, but I have no time to truly test it before the Eurobike show.
Hope that you sort out with a working setup for your needs.

 

[docnjoj]

Thanks for that info Jules. I was right about the regular wind vs the high speed that I didn't get, I think. A problem, to be sure. Depending on what Xiongda is going to do, I will ask for the Lishui controller, although the motor is very quiet with the KT sinewave that I have now. I really would rather have a fixed shift point, particularly since the KT vacillates so much. We are gunna try 20 miles tomorrow, except for the 5% mile and a half hill it is all flat. Going down the hill should be no problem We shall see what happens.
otherDoc

 

[Jonathan in Hiram]

At one point in our email exchange I asked Yona at Xiongda what the RPM of the high speed motor would be on 48V in top gear, I just checked the email and she said it would be 290 +/- 15 with the no load current draw being under 1 amp, that works out to 22 mph give or take a bit, that's no load speed so if you figure under load on semi recumbent it's probably about 18 or 19 mph again @ 48V.

If I set up a motor on the Grin simulator in a semi recumbent bike and throttle it back to 19 mph @ 48V under load then lower the voltage to 36V leaving everything else the same I get something like 15 to 16 mph under load and 18 mph or so no load.

I think you have the fast motor but need more voltage.

 

[docnjoj]

Interesting. That would be good if it is accurate. I really need to know how to identify the motor by a serial number. Perhaps Yona can help. My take on load vs no-load is around 50-60% of no-load which would around 10 mph. I'll do some serious testing tomorrow. I really hope that it is the High speed one.
otherDoc

 

[Jonathan in Hiram]

By 50 to 60% of no load speed a lot of motors are starting to seriously drop efficiency and are making heat. Peak efficiency is where you want to be near for flat level cruising and that's more like 80% or even 85% no load rpm.

The green curve on the Grin simulator is efficiency, I set this up to have no load at 20 mph (where the red and blue lines cross zero) and as you can see peak efficiency is not far below that at 17 mph or so. By 50% of no load at 10 mph the efficiency is down to 55% or so and the motor is making a lot of heat.

 

[endlessly_ending]

By 50 to 60% of no load speed a lot of motors are starting to seriously drop efficiency and are making heat. Peak efficiency is where you want to be near for flat level cruising and that's more like 80% or even 85% no load rpm.

One has to be careful in interpreting such plots.
Those are under the assumption that the motor is under full throttle and under full load.

Efficiency raises considerable when load is lowerd (pull back throttle a little bit) even at half no-load rpm.
Those graps are a little bit misleading in this respect, actually better would be to look at heat generation - and thus efficiency - always with respect to torque = phase current (no simu I know of is doing this though).


But anyway, taking half no-load speed as a rule of thumb where any motor becomes more of a heat generator as we would like, is exactly the point why the XinongDa 2-speed hub is my favorite. It effectively extends the usable rpm band down to 1/4 of the no-load rpm on high grades (and even lower with the trottle pulled back a little bit)


Below one can see what torque and power is needed going uphill at various loads and speeds.


(rolling resistance not included)

 

[endlessly_ending]

For those who are interrested:
Bonnie and her father - who invented of the XiongDa 2-speed hub - will be on the EUROBIKE 2014 as well, as she told me
http://endless-sphere.com/forums/viewtopic.php?f=3&t=61795&p=936892#p936892

 

[docnjoj]

I just got an Email from yona and she suggests cutting the temperature sensor to perhaps allow higher rpm. I am finally going to do a complete 20 mile test on both Saturday and Sunday and will report back on Monday. I'll post the diagrams that she sent. Looks interesting. 'Unfortunately she didn't answer my question as to how to know a high speed motor from a regular one.
otherDoc

 

[m52 power!]

Is the lishui controller much larger than the KT? What are the dimensions of lishui?

 

[endlessly_ending]

I just got an Email from yona and she suggests cutting the temperature sensor to perhaps allow higher rpm.

I wonder what she probably meant?
Do you have a new motor version that has a built in termo sensor?
And why should it help any to cut it for running at higher rpm?
Are you really overheating the motor?

Did you check the assistance level of the display?
My Lishui sine plus the KM-5S combo does limit throttle by the chosen level of assistance. Its only in "power" mode that you get full torque and speed

This is not the case with the King Meter (sine or rectangular) plus LCD3 combo. There throttle is completely independant form chosen level of assistance.

 

[endlessly_ending]

Is the lishui controller much larger than the KT? What are the dimensions of lishui?

They are almost identcal in size

 

[docnjoj]

I'm now quite sure that I have the regular speed motor from what Yona states. Here is a picture of what xiongda is asking me to cut.
otherDoc