2 Speed Xiongda hubmotor

[docnjoj]

it started off fine but after I fiddled with the KT-LCD3 a bit the automatic shift started hunting between low and high.

This is "normal" with automatic shift.
When shifting to low gear, there is much more torque and thus speed rises and so the controller shifts up to high gear - gets slowed down as having too low torque for your break and so on.

Seen from this perspecive its better to not ask for a fixed speed where it shifts gear but to decide on a clever mix of speed and torque when to actually shift up or down.
IMO the KT rectangular controller works pretty well in this regard.

I definitely agree. Apparently there 3 levels of programming A,B,and C. More levels than instructions call for. Interesting. Now I have to figure out what they mean.
otherDoc

 

[endlessly_ending]

Yeah in a 20" wheel you certainly need more Volts if you have a slow / normal winding. The big capacitors in the Lishiu controller are rated at 50V.
The good thing with small wheels is the good efficiency of the motor there.

Did a test ride with 46-47Volts at a decent hill today, with the KT sine wave controller hooked up, 5-10% probably - staying in low gear at a speed of +15km/h (120kg / no pedaling / full throttle ) the motor barly got warm.
This might be more or less the same load you will see in high gear at your small wheels.

The controller got hot though.
Also the KT sine controller does not match with the K-5S display as it seems.

 

[docnjoj]

Yeah in a 20" wheel you certainly need more Volts if you have a slow / normal winding. The big capacitors in the Lishiu controller are rated at 50V.
The good thing with small wheels is the good efficiency of the motor there.

Did a test ride with 46-47Volts at a decent hill today, with the KT sine wave controller hooked up, 5-10% probably - staying in low gear at a speed of +15km/h (120kg / no pedaling / full throttle ) the motor barly got warm.
This might be more or less the same load you will see in high gear at your small wheels.

The controller got hot though.
Also the KT sine controller does not match with the K-5S display as it seems.

Well I did order the high speed wind so I wouldn't have to add batteries. I only need 17-18mph top speed so we will se tomorrow on the bike path. Can't go too fast due to runners with ear plugs listening to AC/DC on 11. Also the dog walkers generally are OK but sometimes we have to stop to make them shorten their leashes. I always stay 1 wheel on the trail even with 4 abreast walkers. If I stop they have to go around us.

 

[docnjoj]

Hmmmmm..........I just ran up the motor with a freshly charged battery and it went to about 45 mph free running. Maybe it is the fast wind. Naturally, the day I want to test, today, it is pouring cats and dogs out. Such is life.
otherDoc

 

[docnjoj]

Well...first report is an F. It hunts for gears constantly and does this on hills in automatic. Yes it works in manual shift, but I don't need extra work to do. I want the automatic to work. Also I cannot roll the bike backwards. The gears lock up. I am writing to Xiongda as we speak.
otherDoc

I just discovered that if you have the switch in the middle "auto mode" the gears do unlock and it can be rolled backwards. It's a start. It seems to work when the power is turned off too.

 

[docnjoj]

it started off fine but after I fiddled with the KT-LCD3 a bit the automatic shift started hunting between low and high.

This is "normal" with automatic shift.
When shifting to low gear, there is much more torque and thus speed rises and so the controller shifts up to high gear - gets slowed down as having too low torque for your break and so on.

Seen from this perspecive its better to not ask for a fixed speed where it shifts gear but to decide on a clever mix of speed and torque when to actually shift up or down.
IMO the KT rectangular controller works pretty well in this regard.

I definitely agree. Apparently there 3 levels of programming A,B,and C. More levels than instructions call for. Interesting. Now I have to figure out what they mean.
otherDoc

Well perhaps not so good. I have a small rectangular controller and it hunted and pecked but never could find the right gear on a hill or on level ground. It seems to shift when it feels like it. Something screwy with the program, I believe. It holds it's gear downhill, but that is not a time that it matters, since it is freewheeling then anyways. I guess I'm the kind of person that needs a "fixed shift point".
otherDoc

 

[endlessly_ending]

If you'd like fixed shifting points the best point for shifting to high gear is past that speed where the high gear has higher torque than the lower gear or in other words where the lower gear runs out of steam in its upper most rotation speed.
Otherwise you get a misbehaviour like you already described before.

But if you are in high gear on a road with increasing grade, then the down shift speed must be at the point where the lower gear has equal or higher torque.


Thats the minimum requirements that make sense at all. Not that this is any new.
But it also means that shifting up and down at exactly the same point of speed never makes sense.

Edit
Depending on the load (weight and grade) and battery power it might be best to shift that "fixed" points as well, as any car does.

 

[docnjoj]

Now that I am over my initial "Shock" of the problem with shift points, I do have some positives to say about the XiongDa motor system.
1. It is fairly quiet and does not make excessive gear noise. Really more like a "woosh". rather than a whine.
2. When held in the correct gear it seems powerful enough for my type of riding, mostly flat but with long 4-5% hills at the end of the 20 mile ride.
In those two areas it meets or exceeds my expectations.
I just want it to shift automatically in a regular shift. I do like the manual control for certain situations, but auto mode is the safest for general riding.
otherDoc

 

[docnjoj]

If you'd like fixed shifting points the best point for shifting to high gear is past that speed where the high gear has higher torque than the lower gear or in other words where the lower gear runs out of steam in its upper most rotation speed.
Otherwise you get a misbehaviour like you already described before.

But if you are in high gear on a road with icreasing grade, then the down shift speed must be at tthe point where the lower gear has equal or higer torque.


Thats the minimum requirements that make sense at all. Not that this is any new.

Yep! That is the way it should be. Kind of like the old Buick 2 speed auto transmission. Either way, the shift point needs to be constant, and hold till torque/speed requirements change. It cannot hunt for the right gear all the time, especially on hills. I can't test tomorrow, but Thursday or Friday I can do 20 miles one level ground with a big hill at the end so I can perhaps keep it in an appropriate gear.
otherDoc

 

[endlessly_ending]

Yep! That is the way it should be. Kind of like the old Buick 2 speed auto transmission. Either way, the shift point needs to be constant, and hold till torque/speed requirements change. It cannot hunt for the right gear all the time, especially on hills.
otherDoc

I guess this will become a never ending side story to the XiongDa concept.
The more options (second gear) the more confusion/ opinions.

 

[docnjoj]

Yep! That is the way it should be. Kind of like the old Buick 2 speed auto transmission. Either way, the shift point needs to be constant, and hold till torque/speed requirements change. It cannot hunt for the right gear all the time, especially on hills.
otherDoc

I guess this will become a never ending side story to the XiongDa concept.
More options (second gear) more confusion.

I hope not since I do like the motor and the concept. I wonder how SRAM solved this problem? They seem to have few complaints, but much higher cost, and don't sell a "kit", only complete bikes.
otherDoc

 

[Jonathan in Hiram]

So what kind of speed did the motor do in the 20" wheel and at what voltage?

Manual shifting wouldn't bother me but I need something that will do 25-ish mph on the flat on 12S with maybe a bit of pedaling on a semi recumbent bike with 20" wheels and still have halfway decent climbing capability.

I've found a small Conhis DD hub that will do my level cruise easily and have some left over but it's not going to climb for crap, even a five percent grade would be a major problem for it.

 

[docnjoj]

So what kind of speed did the motor do in the 20" wheel and at what voltage?

Manual shifting wouldn't bother me but I need something that will do 25-ish mph on the flat on 12S with maybe a bit of pedaling on a semi recumbent bike with 20" wheels and still have halfway decent climbing capability.

I've found a small Conhis DD hub that will do my level cruise easily and have some left over but it's not going to climb for crap, even a five percent grade would be a major problem for it.

Well it is hard to say at this point. It gave hints that it has enough power but I didn't test it by holding it in gear. I was mainly interested in if it would shift reasonably by itself, and it did not seem to do this without dropping out of the correct gear. I'm not sure if this is even the fast wind, since there were no markings on the motor. If the shift problem gets solved, it may be powerful enough for hills. The trike weighs about 40 kilos and I weigh about 100 so close to 300 lbs or so. I will resume testing on Thursday or Friday on a longer (20 mile) rout with a big hill, and we should know more. Oh yes I am using 36 volts from AMP 20 A123 cells. 12S.
otherDoc

 

[Jonathan in Hiram]

Some kind of programmable shift points is probably what it needs, something you can set from the LCD for both up and down shift separately. RPM and current going to the motor (torque) are both known. It seems like some code to stop the hunting back and forth wouldn't be that difficult to implement.

Since the bike weights are dominated by the rider weight there's a lot of difference to account for when setting something like that up, a 90 lb woman on a folding bike with 16" wheels and a teeny battery is a not going to shift the same as a 200lb plus guy on a long bent with 20" wheels and a kwh of cells.

 

[docnjoj]

Some kind of programmable shift points is probably what it needs, something you can set from the LCD for both up and down shift separately. RPM and current going to the motor (torque) are both known. It seems like some code to stop the hunting back and forth wouldn't be that difficult to implement.

Since the bike weights are dominated by the rider weight there's a lot of difference to account for when setting something like that up, a 90 lb woman on a folding bike with 16" wheels and a teeny battery is a not going to shift the same as a 200lb plus guy on a long bent with 20" wheels and a kwh of cells.

Yep those be the problems. I an still not sure why it would upshift on a hill to high gear. That is trouble with a capital T. Oh yeah, the meter was reading 300-400 watts on hills. It actually may be powerful enough in low to haul me up a hill and accelerate, but I wont know till Thurs/Friday when I have time to test again.
otherDoc

 

[docnjoj]

I just read the manual (all36 pages) and there doesn't seem to be much if anything regarding the 2 speed motor. The trike runs fine with the settings of 20" wheel and speed in mph, except, of course for the psychotic shifter. Nothing specific to Xiongda. Am I missing something?
otherDoc

 

[drsolly]

My experience of this is that sometimes the autoshift works nicely, sometimes it hunts. I'm not too bothered, because I've been expecting to do manual shifting anyway. I'm planning to take the bike out tomorrow for some rough riding, I'll see how that feels.

I've also seen the lockup (can't move the bike backwards). Thanks for the tip of putting it in autoshift to prevent that.

Also, I'm thinking about using an Infineon controller on the motor; in that case, there won't be any autoshifting anyway

 

[docnjoj]

My experience of this is that sometimes the autoshift works nicely, sometimes it hunts. I'm not too bothered, because I've been expecting to do manual shifting anyway. I'm planning to take the bike out tomorrow for some rough riding, I'll see how that feels.

I've also seen the lockup (can't move the bike backwards). Thanks for the tip of putting it in autoshift to prevent that.

Also, I'm thinking about using an Infineon controller on the motor; in that case, there won't be any autoshifting anyway

You are a better man than I am..........DrSolly. I have the throttle, 2 gear shifters and some stupid buttons on that screen to watch, so I am in overload with another choice to make. Luckily I ride fairly slowly (15 mph or less) on the bike path. I really want that auto to work. I'm guessing that controller has a reverse gear?
otherDoc

 

[d8veh]

You don't get the lock-up when reversing if you stop in high gear. Just put it in high, blip the throttle, and then it'll roll backwards OK.

I have the first square-wave controller. The automatic shift is generally OK as long as you don't ride at around the conditions for gear-change, where there's a little bit of instability. Even when pedalling at a constant speed away from the change conditions, the controller seems to stop and have an occasional think about whether it needs to change. It also often does it when I go over a bump or change gear. You don't get this with the throttle.

The PAS sensor is the most sensitive I've ever used. The motor stops and starts immediately with the pedals. I lost a magnet from the disc, which made the bike unrideable because of pulsing. As I don't get the pausing when I use the throttle, I'm wondering if your problem is coming from the pedal sensor rather than the gear-change logic. Is the sensor very close to the disc?

 

[docnjoj]

I am only using the throttle. No Pedalec hooked up. It may be that an earlier controller will work better.I did get the sinewave version with the LCD-3 but there does not seem to be a way to alter the shift points. I did write to Yona and she replied with questions. I can't test it until tomorrow or Friday due to previous commitments. Will do 20 miles then for a true test. At least the hi-low buttons keep it in the right gear.
otherDoc

 

[drsolly]

I took the bike out on a rough ride today; about 10 miles over very rough terrain, and lots of stopping and starting. I was in low gear the whole day, except for a short time when I was on tarmac. The autoshift worked fine then. I think it shifts up at about 11mph, down at about 8. Maybe someone could confirm that? But I actually prefer doing manual shift.

I can get up to 12 mpg in low gear (12s lipo), and I tend to ride at about 10 mph maximum, so I'm happy.

I do like the voltage indicator, and the watts.

The temperature gauge does nothing, but my own-fitted gauge told me that the temperature peaked at about 32C, after I rode across a rough field. And the motor felt rather warm to the touch. But I don't see that as a problem.

There's a short pause sometimes when I apply throttle before the controller starts the motor, less than half a second. Slightly annoying. But it beats the pants off the bike I was using for the last few weeks, which had no halls, so getting started was always an issue.

Overall, I love this motor. It's 250 watts, so it's UK street-legal, yet it gets me up hills and over rough ground.

 

[eMax]

I took the bike out on a rough ride today; about 10 miles over very rough terrain, and lots of stopping and starting. I was in low gear the whole day, except for a short time when I was on tarmac. The autoshift worked fine then. I think it shifts up at about 11mph, down at about 8. Maybe someone could confirm that? But I actually prefer doing manual shift.

I can get up to 12 mpg in low gear (12s lipo), and I tend to ride at about 10 mph maximum, so I'm happy.

I do like the voltage indicator, and the watts.

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?

 

[cwah]

I took the bike out on a rough ride today; about 10 miles over very rough terrain, and lots of stopping and starting. I was in low gear the whole day, except for a short time when I was on tarmac. The autoshift worked fine then. I think it shifts up at about 11mph, down at about 8. Maybe someone could confirm that? But I actually prefer doing manual shift.

I can get up to 12 mpg in low gear (12s lipo), and I tend to ride at about 10 mph maximum, so I'm happy.

I do like the voltage indicator, and the watts.

The temperature gauge does nothing, but my own-fitted gauge told me that the temperature peaked at about 32C, after I rode across a rough field. And the motor felt rather warm to the touch. But I don't see that as a problem.

There's a short pause sometimes when I apply throttle before the controller starts the motor, less than half a second. Slightly annoying. But it beats the pants off the bike I was using for the last few weeks, which had no halls, so getting started was always an issue.

Overall, I love this motor. It's 250 watts, so it's UK street-legal, yet it gets me up hills and over rough ground.

How does it compare to your other motors?

 

[d8veh]

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?

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.

 

[docnjoj]

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?

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.

As usual, D8veh is right. I was able to get the offset with some washers and hand spread the rear dropouts a few mm. I do have the 135 mm version, and no rear brakes, so the centering did not have to be perfect. It was close ,maybe 2mm off. The bikeshop tech said that because of the spoke length, I would not be able to dish. If I ever redo the wheel I will get spokes 2 mm shorter. More short road test today.
otherDoc