2 Speed Xiongda hubmotor

[Alan B]

"Your small wheeled, light bike presents a reduced load. Losing 1.5 seconds of time during climbing on a steep gradient is a significant loss of powered time. If it hunts then the loss could be 4.5 seconds or more. I recall someone writing that autoshifting was so slow and late that it was not useful."

You have not presented any examples from your experience of autoshifting being necessary or important. Are there any you wish to share?"

* My "small wheeled bike" is actually heavy, and carries 2 riders And because of the way gravity works, loss of speed during shifting is not dependent on weight anyhow. Also in practice, you can not downshift a Xiongda manually any faster than it downshifts automatically. Please point me to the page of any poster who says otherwise - the elusive "someone".

* "Hunting" is the repeated downshift, speed up, upshift, failure to maintain speed upon upshift, and then resultant repeat of the downshift. It has NOTHING to do with "4.5 seconds or more" of delay.

* The advantages of autoshifting are intuitively obvious. One less thing for the rider to think about. Improved motor life from shifting that is programmed to reduce motor shock and to keep the motor in it's best range. I actually prefer manual shifting cars, trucks, motorcycles, but like the fact that my wife can exploit 2 speed bicycle motor operation without having to think about which gear she is in. If you don't like autoshift, that; your preference. But I have yet to see any posts pointing out any problems with autoshift that would be reduced/solved without it being available. Please point out the thread page of any such posts...

When climbing the duration of the shifting time affects the amount of speed lost.

Hunting causes even greater loss of (time) useful work (integrated torque) and greater loss of momentum and velocity on gradients.

Many have noted it shifts too late on uphill gradients (which is about the only time I would use low gear), and that we know is a "normal" response of a transmission's control system. Unlike a rider with eyes who has lookahead capability the transmission needs to lug down before it shifts so it has already wasted time and is starting late, especially with such a slow shifting process. The optimal time to shift is before the motor lugs and loses speed. Manual and automatic shifting both use the same shifting algorithm, however automatic shifting is reactionary where a rider's shifting can be better timed with experience, anticipating the increased load. Since shifting causes clutch wear reduced shifting increases motor clutch life. On gradients where high gear is adequate there is no need to use low speed at all. It is only needed on steep gradients, and then there is no need to shift until the gradient falls below the required threshold. Shifting more just causes unnecessary wear. If you look at the modeling, in cases that low gear is required, there is no speed at which high gear has adequate torque. So it is not like an ICE where shifting allows it to speed up and then changing gears allows it to continue to accelerate. With the torque curve of an electric it can either start in high gear or not. If it can't start in high gear it can't operate in high gear at any speed - it needs to start in low gear and stay there. It is a "range" selection, not a gearshift. There are many ES threads on shifting and gearing for electric motors, the Xiongda follows the same physical principles.

Compared to a 29" wheel a 16" wheel decreases torque load on the motor by the ratio 29/16 or 1.8125 which is a large reduction, nearly the reduction of low range on a 4WD vehicle (and almost as much reduction as the range shifting itself).

The disadvantage of autoshifting is that it limits you to a weak controller with low voltage capacity and little capability for adjustment or improvement. I do agree it could be good for an untrained user, or one that won't bother to learn how to best time the shift.

This discussion appears to be going in circles so it is probably best to let it drop.

 

[craiggor]

Mine has Never auto changed,is there something in the display settings to turn it on ? All the talk about hunting at the beginning of this thread made me stick with manual change.

Sent from my D101 using Tapatalk

 

[2old]

Too bad d8veh, who started this thread, doesn't seem to post here anymore. He's had a lot of experience with this motor. Starting to rain in socal; maybe there's something like a winter project here (after five or more years of drought).

 

[craiggor]

It depends on which controller and which display you have. IIRC there were at least 3 combinations, and at least one did not offer the autoshift feature. I believe at least two that did offer it were reported to implement it in slightly different ways. There were people who did like and people who did not like each of the combinations for a variety of reasons.

Whether or not the auto shift is a good thing, or a bad thing, is a matter of opinion but there was a majority who were not using it for, again, a variety of reasons.

This is why Baskin-Robbins offers 31 different flavors.

They do not offer any flavors at all which have been shown to cause any significant number of their customers to develop a sudden need to change their underwear, even though there do exist folks who find that a warm and comforting feeling. The majority find it unpleasant.

It would seem that careful and specific control over the timing for commencing an disengage/engage sequence for the two clutches and two gearsets, along with a reversal of motor rotation, combined with a reduction in the frequency of this operation, carries a high probability of enhancing longevity of the motor. This course of action seems best implemented by manual shifting as compared with the automatic function.

For the short version, "Shift less and it will likely last longer".

Cheers,KT36SVPR-XDO20SS controller no plug for the HAL switch KT LCD 3 display.Suppose I stick with the vanilla.

 

[Alan B]

I already posted my results on backwards rolling. If you stop in high-speed mode, it always rolls backwards. If you stop in low-speed mode, most of the time it doesn't rotate backwards, but if you spin the motor in high-speed mode, and then switch back to low-speed mode without putting a load on the motor, it will roll backwards in low-speed mode.

There'e a lot of mechanical noise from the motor, like chattering and buzzing, which I don't think are related to the electrical pulses. I think that this is why you don't get a significant noise reduction with the sine-wave controller. The noise is a little too much for OEM bikes. My thinking is that Xiongda were hoping that the sine-wave controller would solve the noise, but it didn't, so now they are changing the design of some of the internal components, which is what is causing delays to the production. It's only a theory.

Regarding stress testing, I run mine at 20 amps. It's done a very hilly 300 miles so far pulling a total weight of 130kg. I also have a 36v at 44v (12S), but I haven't done many miles on it yet.

An early note from this thread, note especially comment on rolling backwards.

 

[Alan B]

It's a lot easier to open the motor when new for greasing because the chain pulls on the free-wheel, which turns the side-plate, so tightening it on its thread.

another useful tidbit from early in this long thread.

 

[Green Machine]

Can anyone on this long threat please tell me if they have a 3d drawing of the tool required to open this motor? IF someone could agree to share or sell me that 3d drawing i would share pics inside the motor.

By the way i dont jsut need the tool to open the motor and of course we can get it open and have had it open....

i want to have a tool readily avaiallable to custoemrs so in the event of a failure we can sent them the tool and ad replacment part or motor.

And why in all this drivel and badgering of me and demanding this or that info.....none of trolls simply asked me if i would send pics inside the motor?

I am meeting with the owner of Xianghu next week...... i will be sure to send pictures of me and him drinking beers and thumbs upping.

Thanks Alan B for always being so fair and so impartial..... and being a true engineer and always being modest and helpful with your knowledge.

I am happy to send you a kit for testing. You have always been a great asset to this community.

 

[Alan B]

I haven't felt too well the past few days, so I'm slowly working my way through this 51 page thread from the beginning, again. I've seen two ways discussed of getting the motor open, using a pin wrench on the two holes or slots near the axle about one inch apart, and with homemade tools using the threaded holes on the motor side plate with shorter screws than normal. If I come across something specific I'll note it here.

 

[Alan B]

I have purchased 2 of these motors for 700C road bike application.

First of all the motors appear very high quality, they came with sine wave controllers and they operate quietly.

I am having 1 very bad problem which even xingda cannot figure out. That is when in AUTOmatic mode the motor starts in high gear and NEVER downshifts. It doesn't matter if I'm on a hill or not it just does not work. The motor will use high and low when manually shifted from the switch just no auto. I have tried with PAS, with throttle, high grade and low grade hill, level ground, using brakes to simulate loads etc, it just never downshifts!

Xiongda has sent me 2 new batches of motor controllers and STILL it does not work. The latest batch is actually worse, it constantly switches between High and Low gear about 2 seconds apart and never gets above 17/18KPH.

They are completely stumped and so am I, is there anything you guys can think of that would cause this?

Example of shifting problems. More shifting problem and low power and low speed discussion on page 14. Using higher voltage and more programmable controllers is helpful with this motor.

 

[2old]

Eric; my advice:

1) Listen to ones who applaud your efforts, not your detractors.

2) Discount completely anything N37 said.

3) Consider contacting d8veh (he still posts on pedelecs, but apparently not here anymore --- can't blame him if he's encountered some of these individuals).

4) Have seen neither the motor nor the tool that you mentioned, but it may be like a "spanner" we used to utilize when adjusting old time bottom brackets. The tool is "like" Park Tool SPA-2 & SPA-6 "Cluster Cone Pin Spanner". Also put "Bike Hand YC 155 into your browser.

 

[Alan B]

Can anyone on this long threat please tell me if they have a 3d drawing of the tool required to open this motor? IF someone could agree to share or sell me that 3d drawing i would share pics inside the motor.

By the way i don't ... need the tool to open the motor and of course we can get it open and have had it open....

...

Here's a photo of Bruce Teakle's tool:

(From Here): http://bruceteakle.blogspot.com/p/it-seems-clear-xiongda-2-speed-motor-is.html

It is just a lever that mates with two of the motor holes, and appropriate length screws.

 

[2old]

Alan, good find; that tool looks like what we used to use, but ours was either the SPA-type or Bruce's tool, but shaped like a "Y". His looks like it supplies much more leverage.

 

[Alan B]

I would think a simple flat plate could be made that would have the two holes (or all three), a hole for the axles, and a 1/2" square drive for a socket drive could be made by waterjet (it would have to clear the edge of the motor). Perhaps stainless steel, or thick 6061 Aluminum.

 

[Alan B]

I took the bike out for a test run. It's powered by 12s of Lipo. ...

In low gear, the top speed was 12mph, in top gear it was 20 on the level. That's pretty good for a 250 watt motor.

I took it to my local steep hill test road. It climbed it at 7 or 8 mph, with only a very slight encouragement of pedalling; most of the hill it could climb without any help.

...

The autoshift does work; when the speed falls to around 7 or 8, it changes to low gear, and at 12 or so it changes to high. But, obviously, it has no anticipation. When it changes gear, you lose power for about a second. My feeling is that I'll prefer to make my own choice when to be in low and when to be in high, based not only on my current speed, but also on what I can see coming up ahead of me. So I think that for me, the autoshift won't be very useful.
...

Another comment on autoshifting, this from page 11. Lots more discussion and testing from page 12.

On page 16 otherdoc indicates a new controller has fixed most of his shifting complaints, however from his current sig it appears he no longer uses the XD motor on his trike, so it appears he may have given up on it for some reason.

 

[Marin]

Eric; my advice:

1) Listen to ones who applaud your efforts, not your detractors.

2) Discount completely anything N37 said.

3) Consider contacting d8veh (he still posts on pedelecs, but apparently not here anymore --- can't blame him if he's encountered some of these individuals).

4) Have seen neither the motor nor the tool that you mentioned, but it may be like a "spanner" we used to utilize when adjusting old time bottom brackets. The tool is "like" Park Tool SPA-2 & SPA-6 "Cluster Cone Pin Spanner". Also put "Bike Hand YC 155 into your browser.

if there was a like button I'd like, LIke,

 

[cycleops612]

Eric; my advice:

1) Listen to ones who applaud your efforts, not your detractors.

2) Discount completely anything N37 said.

3) Consider contacting d8veh (he still posts on pedelecs, but apparently not here anymore --- can't blame him if he's encountered some of these individuals).

4) Have seen neither the motor nor the tool that you mentioned, but it may be like a "spanner" we used to utilize when adjusting old time bottom brackets. The tool is "like" Park Tool SPA-2 & SPA-6 "Cluster Cone Pin Spanner". Also put "Bike Hand YC 155 into your browser.

if there was a like button I'd like, LIke,

If there were a like button i would "like" the idea of a like button.

 

[Alan B]

For a moment I was going to look for the like button to like the suggestions of having one.

 

[2old]

Eric & Alan, one last minute thing. The tool was basically a flat plate like Alan described with a "yoke" to go around the axle and a handle for leverage. The "ears" were tapped and allen screws a little longer than the thickness of the metal were tightened and protruded slightly. These were inserted into the holes. Sorry if I'm being too simplistic.

 

[Alan B]

Eric & Alan, one last minute thing. The tool was basically a flat plate like Alan described with a "yoke" to go around the axle and a handle for leverage. The "ears" were tapped and allen screws a little longer than the thickness of the metal were tightened and protruded slightly. These were inserted into the holes. Sorry if I'm being too simplistic.

That's about right. As I understand it there are a couple of ways to get traction on the side plate to loosen and rotate it. The pin holes (or slots) and the screw holes. There are some differences between variations of the motor depending on whether front or rear types (at least). I would caution against using anything in the screw holes that doesn't match their threading. Applying force to the threads should only be done with a matching thread, otherwise the threads could be severely damaged.

I found one tool that levered the axle threads against the threads in one hole with a rectangular aluminum tube. I didn't link that (it is in this thread) because that could easily cause thread damage. There are also folks using combination wrenches to lever a capscrew against the axle (or the freewheel threads). Again this could cause thread damage. It would be better to lever against an axle nut, but the example photos didn't do that and it appeared to be levering against threads which concentrates a lot of force on their weakest feature.

The disc brake mount is on the wrong side plate, so that doesn't help.

I don't have one of these motors in hand to really inspect it, so I'm depending on what I can find on ES and elsewhere for this info.

 

[Green Machine]

ok thanks guys for all your help. I really appreciate.

I am gong to be taking a long break from this forum ... but i will be sure to check back from time to time. i gotta keep my eye out that i am not being slandered because there are some serious liars and trolls in our midst.

i will check back for a bit because i will be meeting very soon with the owner of xiongda and visiting the factory... i will be sure to post a pic of drinking beers with him and acting silly.

I love 97 percent of the people here.. but miss what it use to be when it truly was free.

But its getting way to negative for me....

Also i have my own forums and webistes i have been neglecting and i only have so much time.

I never meant to spam you guys...i alwys considered es my home... if anything i always strived to gain acceptance from my commmuntity which to me is more important than to most.

Its the nature of the universe at some point the trianing wheels should come off and its time to fly.

Leaving for china in the morning......

ERIC

 

[2old]

Eric & Alan; I've never seen one of the motors, but the tool seems like the Pittsburgh Adjustable Pin Wrench (Harbor #36554); should make it non-adjustable since it's for one "spread" and with a longer handle for more torque. However, I could be very mistaken.

 

[craiggor]

Here's D8veh method of opening a new unused hub.

I would not like to try and hit the spanner hard on a used hub in case I damaged the thread on the free wheel. Mine had done 1400 miles when I opened it.so I made a tool similar to Bruce's,out of some scrap I had lying around it all ready had the big hole in it and one of the small holes witch was slightly to big.I put some washers in that to take up the slack.I'm no engineer so any one with a welder grinder and drill could knock one of these together.

 

[cycleops612]

Probably a silly suggestion, but maybe hold the disk brake hard on, and twist on the tire/rim?

 

[Alan B]

Probably a silly suggestion, but maybe hold the disk brake hard on, and twist on the tire/rim?

As I understand it, the disc mounting holes are on the wrong side plate.

The black tool a couple of posts above looks like it would work.

Using a combination wrench as shown above that levers against the freewheel threads could easily damage those fine threads.

 

[docnjoj]

"On page 16 otherdoc indicates a new controller has fixed most of his shifting complaints, however from his current sig it appears he no longer uses the XD motor on his trike, so it appears he may have given up on it for some reason." Quote from AlanB.

Yes I did give up after the 2nd time rebuilding the motor. The new controller worked fine for shifting, but then that damn Sun gear stripped again. I broke all 3 hardened screws trying to open the motor and put the motor back together with steel epoxy in the screw holes. I don't use it because I may have to rebuild it again and can't put screws in the holes.
Now using a Cute100H. Not as versatile as the 2 speed, but doesn't break.
otherDoc