2 Speed Xiongda hubmotor

[knutselmaaster]

That is what i had;
The (7speed) wheel fitted without stretching but i could not get the disc in the caliper.
I had to put an extra ring on the axle, disc side, to get it right, forcing me to stretch the frame.
It wasn't hard on the aluminum frame though.
Just to say, the given sizes are in an ideal situation, it is very possible that you need to make the motor a bit larger on the axle to make the gears and disc align nicely.

 

[d8veh]

In practical terms, you can't really go any wider than 8 speed because the rim needs to be off-set to keep it central. I widened mine to about 150mm for an 8 speed cassette, for which I had to put some spacers on the disc side to reduce the off-set, but this meant that the drop-outs were no longer parallel. Also, the disc caliper mount was no longer parallel to the disc, so that too needed spacing with washers to bring it back in line.

In summary, 7-speed is enough. You can get a cheap used changer and derailleur from Ebay, which will work pretty well and save a lot of hassle.

 

[d3m]

Hello, This is my first post of this forum.
Please permit my poor English.

I think there is cause of the rollback issue in a green part of picture.
When internal motor does rotation in normal direction[strike](Low gear)[/strike](High gear), the green part moves, and ring gear(red part) becomes free in both direction.
And When motor stopped, the green part turns back by springs.

If the green part doesn't return for some reasons, ring gear is free, and sun gear(orange part) is locked.
As a result, rollback of motor is prevented.
I think this trouble can be reduced, if reducing green part's friction.

 

[menvert]

I think that logic is basically correct, though I think it is when in high (Yellow sun gear engaged) that the green part locks clockwise, and allows the red low gear to spin freely.
However I am not sure better lubricant will really change it, when I recently flushed and re-lubricated the whole clutch mechanism with very thin libricant - it still has the roll-back issue, I'd even say it is now worse than when I had thick grease.
It may be more of an issue that the springs are not strong enough or too strong to return the green bit to 'neutral' properly

It's probably just too hard to tune it so it can Free-Wheel forwards reliably (which is very critical) but also allow it to spin freely when reversing the bike

EDIT:

Thinking even more: when pushing bike in reverse the blue/green sections are going clockwise (in the diagram) and push the roller-clutch against the springs, so they are probably momentarily bouncing off the spring and engaging

Actually that idea is probably not correct as I think the diagram is drawn as if looking through the casette/freewheel, so rolling backwards would be the Blue section going anti-clockwise which cause it to engage if any or the yellow rollers happen to find some friction (helped by the springs), which makes sense in regard to Doc's past damage to the Sun gear.

 

[knutselmaaster]

Thought it would be helpful to share these:

about the stuck problem. We have some stuck problem months ago. when L gear, the motor
get stuck, it can get back to normal or it get total stucked.
We did some improvement, now it should not be a problem, the resistance we test on the motor
is more than 70N.m now, motor didn't get stuck at this point, it will never get stuck.

And about the version without switch, that has actually got the auto-mode :

the automatic-mode is still avaiable for the no-switch version.
For the no-switch version, if controller and LCD03 's serial number both have "ss" in it. Then in setting 15, number 0 can
active the auto-mode, number 1 is manual-mode.

 

[docnjoj]

Hmmmmm.......... I now agree that the broken Sun gears very likely were related to stuck roll-back. I am trying to be very careful and tried different combinations of High, Auto and Low as I come in from a ride. When you get the right combo, I can hear the clutch unlock and the bike rolls back. Then I go the final 4-5 feet and the rollback still works. I just tried this yesterday so I will try to develop a protocol to free the gears. I hope I can standardize my approach, since broken Sun gears are a real nuisance.
otherDoc

 

[knutselmaaster]

The annoying thing is that when it is locked and you ride off, it won't accelerate.
You need to switch to H and back to A or L to get the motor functioning again...
But it becomes a habit soon enough.

 

[docnjoj]

The annoying thing is that when it is locked and you ride off, it won't accelerate.
You need to switch to H and back to A or L to get the motor functioning again...
But it becomes a habit soon enough.

Mine seems to work OK even when it is locked as far as initial acceleration. It needs to switch down to low to start up and I find that I now leave it in Auto mode all the time. Sometimes I forget on long straight runs and lock it in High, but I then forget to switch back to low after a stop. Mine does not like to start in high gear! So I am learning to just leave it in Auto. I'll bet that is why Xiongda got rid of the switch.
otherDoc

 

[ktmede]

Maybe our calculations are out, I'd have guessed the cassette version would be the same total width as a 8-10s Freewheel version, it would be nice if they can send the schematic (like we have on page 1 or 2 of the thread)

These are the schematic I got for the cassette motor

 

[menvert]

Hmm, okay so it looks like it's 5.4mm wider, but an 8-10sp freewheel would already extend it 4mm, and on my hub a 7sp DNP is also 2-3mm longer. So if you were going 8-10sp I think it's basically the same width. I might have to look how casettes mount as the diagram gives them extra spacing where it almost touches the motor hub.
EDIT: just looked at my original 8sp casette and it is more flush than a freewheel, the freewheel actually has spacers between it and the wheel, but the cassette does not, thus why the freewheel hub has built in spacers

Here are the external dimensions of the 135mm and 145mm dropout versions of the Xiongda rear motors.

These are the schematic I got for the cassette motor

 

[d3m]

I think that logic is basically correct, though I think it is when in high (Yellow sun gear engaged) that the green part locks clockwise, and allows the red low gear to spin freely.
However I am not sure better lubricant will really change it, when I recently flushed and re-lubricated the whole clutch mechanism with very thin libricant - it still has the roll-back issue, I'd even say it is now worse than when I had thick grease.
It may be more of an issue that the springs are not strong enough or too strong to return the green bit to 'neutral' properly

It's probably just too hard to tune it so it can Free-Wheel forwards reliably (which is very critical) but also allow it to spin freely when reversing the bike

EDIT:

Thinking even more: when pushing bike in reverse the blue/green sections are going clockwise (in the diagram) and push the roller-clutch against the springs, so they are probably momentarily bouncing off the spring and engaging

Actually that idea is probably not correct as I think the diagram is drawn as if looking through the casette/freewheel, so rolling backwards would be the Blue section going anti-clockwise which cause it to engage if any or the yellow rollers happen to find some friction (helped by the springs), which makes sense in regard to Doc's past damage to the Sun gear.

menvert, I agree to your idea.
I think my idea is incorrect.

Thought it would be helpful to share these:

about the stuck problem. We have some stuck problem months ago. when L gear, the motor
get stuck, it can get back to normal or it get total stucked.
We did some improvement, now it should not be a problem, the resistance we test on the motor
is more than 70N.m now, motor didn't get stuck at this point, it will never get stuck.

And about the version without switch, that has actually got the auto-mode :

the automatic-mode is still avaiable for the no-switch version.
For the no-switch version, if controller and LCD03 's serial number both have "ss" in it. Then in setting 15, number 0 can
active the auto-mode, number 1 is manual-mode.

It's good information.
I hope to know how they improve the stuck problem.

 

[knutselmaaster]

And now for a funny story :

My son was back on his bike, now electrified with XiongDa, for the first time.
I was biking besides him for several kilometers and then asked him for his opinion.
He told me he liked the added comfort of the huge back tire, and the subtle feeling of lightness the motor gave.
It was like riding a bike that rolled all by itself, and he couldn't hear the motor running he said.
I found that very flattering but a bit awkward because I had set things up to give really good acceleration and he didn't mention that at all and I didn't have any trouble pedaling besides him.
So I told him to raise cadence so that the motor would kick in harder.
He peddled the fastest he could in a lighter gear... and nothing happened.
I looked on his LCD ; it was on 0
So I told him to push the button, and he did while still pedaling at high rpm
And took off with the front wheel suddenly lifting, aaaah!
It was soo funny to see the look on his face !
He was really very impressed by the power and I haven't seen him have fun on his bike like that since he was little.
He doesn't want to be dropped with the car anymore, he takes his bike instead

Later he told me he tried the steepest climb he knew and said that he had to pedal to keep it running.
I asked if he was on L, but he told me he wasn't, because he thought the H was for climbing.
He couldn't believe his ears when I told him it would take that climb at 10km/h without pedaling (I tried) in L gear

 

[docnjoj]

I'm wondering if my physics is correct. The Xiongda 2 speed has a high torque of 70 nm. Now if it is locked up, and I force it backwards against the gears, would it not only require about 1/4 of that "push" to create at least that amount of torque on the high gears? Could this amount of torque break the High Speed Sun gear? Just thinkin' that this may be the cause of broken Nylon Sun gears?
otherDoc

 

[menvert]

Well, when the power input comes from the wheel rather than motor the gearing will be multiplying rather than dividing the rpm, so you will have a lot more resistance to movement, which theoretically will result in high torque loads in the sun or planetary gear, but I don't know if it's enough to break it...

However what I am beginning to think is more likely is that when rolling back both clutches can sometimes engage, which I _think_ is possible in this scenario, you'll be trying to rotate both the sun and the ring gear in the same direction against each other

As far as I can visualize; the se-saw mechanism that ensures both clutches can't engage in normal operation, doesn't always work when the wheel spins in the opposite direction & provides the power input.

My thoery (refer to coloured diagram below) - Wheel causes Blue to move anti-clockwise, and if the Red ring gear engages 1st, it will lock the se-saw and prevent green from rotating, but because it's spinning the wrong way, the Orange sun clutch can still engage (and in-fact once the red is engaged and rotates the planetary gear it will encourage orange to engage too. )
If it's orange that engages first though it looks like it will prevents Red from engaging.

 

[docnjoj]

Sounds right to me. If the motor breaks again I will try polishing the Sun gear metal like Bonnie suggested, but I still think the nylon part breaks due to excessive force when locked and I try to roll backwards. I definitely won't try that again.
otherDoc

 

[panurge]

It sounds logical to me too, but I have to say that with the small fatBike that's equipped with the first XD motor I got an year ago, the backward block and crackling has happened dozens and dozens of times and It still works as the first day.

I have to notice, otherwise, that the Lishui Sine non FOC controller, with speed only logic for the autoshift that I used with that bike/motor, is Burnt just yesterday, while pulling in low gear, @ 10-12 kph, a 60-70Kg trailer over a 10% climb.....unfortunately that could be not purchased again, at least with the same firmware, I think.

Cheers

 

[menvert]

Argh, that's a shame, though I think the KT controllers have improved a fair bit now, and yeah I think the roll back issue is more significant on a heavy trike type bike, on mine I feel it very quickly and stop before it forces anything(well I have no choice really), but I do really think it's not just pushing against the motor, but it's 'locked' by dual clutch engagement, as it doesn't give even a mm when it happens.

 

[panurge]

I think the roll back issue is more significant on a heavy trike type bike, on mine I feel it very quickly and stop before it forces anything(well I have no choice really), but I do really think it's not just pushing against the motor, but it's 'locked' by dual clutch engagement, as it doesn't give even a mm when it happens.

Yes, a trike is indeed heavier than my wallmart 20" fat (maybe ) anyway, that motor is sometimes totally blocked without giving even a mm as you say but more often it makes a crackling noise allowing to move. I remember, at Last Eurobike, with Justin, obviously interested in that having a relatively similar patent pending, we tried to reproduce that block/crackling and it never happens....

I have 3 different type of KT controller right now.....but hey! no one have been comparable to the Lishui+KingMeter display. Figure out that With that bike, until yesterday I was not using the H-A-L switch the last 4-5 months (I mean the switch is not installed at all)
Indeed It seems to me that XD would prefers to use mostly the high gear, but, in absolute terms I would like to have the motor working in the more efficient gear depending on the use. Talking with Justin some days ago, I see that his thoughts are in accord with that. I'll report his exact words: "since the best motor efficiency is always at higher RPMs, if ever the wheel is spinning slow enough that it can deliver power through low gear mode, you should be in low gear mode."

 

[menvert]

I have 3 different type of KT controller right now.....but hey! no one have been comparable to the Lishui+KingMeter display.

Dissapointing they moved away from the Lishui. The 48vKT controller I got about 2 months ago seems worlds ahead of the 36v (Auto was useless on this) previous one, though it's possible it's related to not having the passive speedo anymore... I ordered a speedo sensor and will see, I expect it will just mean I can always use Auto, whereas right now I have to switch to H if I am coasting, as the speedo reads 0 right now when there is no motor accel, if I hadn't gone to a 44v battery I'd have tried to get a LiShui as they sound better esp. faster switching. Though the 48vKT switching does seem faster than my old KT

 

[d3m]

I edited that picture to understand the movement of this motor.
Is it correct?

 

[menvert]

I edited that picture to understand the movement of this motor.
Is it correct?

Looks great, good to see them back on the thread, this version looks to depict the movement perfectly from my understanding.

 

[docnjoj]

I'm not positive but I believe this shows how when in HIgh gear the Sun gear can be forced against the planet gears if the clutches lock up. In that situation the wheel cannot roll backwards, and sun gear damage can occur. Please confirm or tell me where I am going wrong?
otherDoc

 

[menvert]

I'm not positive but I believe this shows how when in HIgh gear the Sun gear can be forced against the planet gears if the clutches lock up. In that situation the wheel cannot roll backwards, and sun gear damage can occur. Please confirm or tell me where I am going wrong?
otherDoc

As far as I can tell this is the normal forwards operation (planet gears being the initial source of power)
During normal forwards H(top Pic) the green bit rotates & pushes the seesaw & rotates it past 90 degrees anti-clockwise which forces the ring to disengage & prevents dual-clutch lock

But in reverse (visualize the light blue rotating anti-clockwise when wheel spins in reverse) the momentum/friction engages the ring clutch and locks the seesaw, It then turns the planet gear anti-clockwise causing the sun gear to go clockwise and that also makes the sun clutch engage

This is almost depicted in the top picture, but the white clutch arrow is in the other direction, green arrow depicts the sun clutch engaging rather than the green bit rotating (as the seesaw now prevents it) and both become engaged... however IF the Sun clutch engaged 1st everything works fine in reverse as the green bit can still rotate and keep the ring clutch away from the friction

 

[docnjoj]

So I should downshift to low just as I am about to bring the trike in to the house at the end of the ride? Would this give the motor the best chance of having smooth rollback?
otherDoc

 

[menvert]

So I should downshift to low just as I am about to bring the trike in to the house at the end of the ride? Would this give the motor the best chance of having smooth rollback?
otherDoc

I don't think either gear will really change the likely hood of roll back-lock, as I think it will just spring back to neutral as soon as you come to a stop.
If you could engage the H sun clutch that'd offer protection, because it rotates green + seesaw which prevents ring clutch engaging

Polishing the contacts as Bonnie suggested and using lubricant that prevents friction as much as possible are the best bet, particularly the ring gear.
With my very thin lube (basically WD-40 with Teflon [PTFE]) - when it catches, I roll forward a touch and it unlocks, I just have to always reverse slow in case it catches.