Sorry to hear of your problem Frank, it sounds vaguely similar to an experience of mine with a Chinese import fitted with a Tonxgin motor. This repeatedly blew controllers, always a short circuit in the same pair of mosfets driving one phase wire, the result was a supply short which would have blown the fuse had one been fitted. The problems continued even with decent mosfets from RS. I later discovered that other owners of that bike suffered the same problems. This bike was not however fitted with the propriety Tonxgin controller, instead using a custom one specific to the bike. Also worth noting is the fact that there were a number of Tonxgin powered "Upland" branded bikes on Ebay, at least one being bought by a forum member. The seller of bikes stating he was replacing the controllers with a modified type before shipping, although the reason was not given. The fact that Schwinn have also had controller problems with this motor does make one wonder what it is about this motor which causes problems with the the controller, normally a reliable component.
TongXin (a.k.a. Nano) motor project
- Thread starter Jeremy
- Start date
Yes, it's a bit of a bore that it hasn't worked out. There are only too many stories of Tongxin controller problems on the internet so I can't say I wasn't warned, however people do seem to be using them successfully so there must be a solution.
I'll send it back to China and, with luck, they may send me one back that works perfectly. I think I'll also contact some of the Tongxin resellers to see if I can track down another controller as a back-up.
Ian, by the way, I owe you some thanks in connection with this as it was only after reading a recent post of yours that I realised I really ought to fit a fuse to the battery and learned how to do it. I would have had greater damage otherwise!
Frank
I'll send it back to China and, with luck, they may send me one back that works perfectly. I think I'll also contact some of the Tongxin resellers to see if I can track down another controller as a back-up.
Ian, by the way, I owe you some thanks in connection with this as it was only after reading a recent post of yours that I realised I really ought to fit a fuse to the battery and learned how to do it. I would have had greater damage otherwise!
Frank
While I'm still waiting for a new controller, I can report some good news regarding the performance of my Tongxin motor.
I've been for a 10-mile ride this morning on the bike which has the Tongxin installed - but no battery and no power. The rolling resistance and impact on the handling of the bike from the freewheeling motor was negligible. It really was as if it wasn't there. Quite different from any other hub motor bike I've ridden.
Now if only it had power...!
I've been for a 10-mile ride this morning on the bike which has the Tongxin installed - but no battery and no power. The rolling resistance and impact on the handling of the bike from the freewheeling motor was negligible. It really was as if it wasn't there. Quite different from any other hub motor bike I've ridden.
Now if only it had power...!
I'm almost certain that like most, it has a freewheel so the motor doesn't turn on overrun or pedalling without power, but there's no doubt that the roller drive which is still driven by the hub will have markedly lower drag than the orbital gear set in all the others.
.
.
Unfortunately not a simple answer!
Forces pushing the rider forwards are:
Motor power
Pedal power
Forces holding him back
air resistance
rolling resistance of tyres
other frictional resistance
At higher speeds air resistance is the main slowing force so the speed mainly depends on how hard he pedals and how aerodynamic his riding position is. One thing that doesn't make any difference is his weight.
Frank
Forces pushing the rider forwards are:
Motor power
Pedal power
Forces holding him back
air resistance
rolling resistance of tyres
other frictional resistance
At higher speeds air resistance is the main slowing force so the speed mainly depends on how hard he pedals and how aerodynamic his riding position is. One thing that doesn't make any difference is his weight.
Frank
As Frank says, it's not easy to calculate. The best you'll get is an estimate using the power calculator here: Bicycle Speed And Power Calculator
I've just used this to give you an estimate, assuming that your bike is an upright style roadster. The answer was 16.8 mph on level ground with no wind.
Most motors will have a peak power output that is much greater than the average power rating on the label though, so you may find that a 240 watt motor will deliver 400 watts or more. My Crystalyte hub motor easily delivers over 1000 watts on 48V, even though it's nominal rating is much lower.
Jeremy
I've just used this to give you an estimate, assuming that your bike is an upright style roadster. The answer was 16.8 mph on level ground with no wind.
Most motors will have a peak power output that is much greater than the average power rating on the label though, so you may find that a 240 watt motor will deliver 400 watts or more. My Crystalyte hub motor easily delivers over 1000 watts on 48V, even though it's nominal rating is much lower.
Jeremy
Thank you for your reply.
It's mostly flat ground where I live and 16.8 mph on flat ground doesn't
sound to shabby.
I intend to use the Tongxin motor using a special controller that only
feeds 240W maximum from the batteries. More like 200W. I can set this.
I will peddle a lot and use the Tongxin to increase the top speed.
The controller will prohibit the motor from getting anything more than 240W
This should keep the motor safe from roller slipping and overload at lower
speeds or standstill starting.
It will only be used at higher speeds, >15 mph at limited power.
It's mostly flat ground where I live and 16.8 mph on flat ground doesn't
sound to shabby.
I intend to use the Tongxin motor using a special controller that only
feeds 240W maximum from the batteries. More like 200W. I can set this.
I will peddle a lot and use the Tongxin to increase the top speed.
The controller will prohibit the motor from getting anything more than 240W
This should keep the motor safe from roller slipping and overload at lower
speeds or standstill starting.
It will only be used at higher speeds, >15 mph at limited power.
Hi Honk 
I agree that there are many factors which affect the accuracy of any estimate, but if its 240W power input as you say, an important factor (apologies if you already accounted for this Jeremy) is the power loss due to inefficiency between input & output from the motor: if your motor is 75% efficient say, then 240W input amounts to about 180W of useful output motor power. Also, if that is the peak power output, i.e. 24V & 10A current limit, then the output at maximum efficiency will occur at a higher speed, and will be less power than that again (how much less & the speed difference depends on the motor, but the tongxin looks to have a smallish difference in revs/speed between the two).
I'd say with around 180-190W power output at top speed you might get as much as about 16-17mph as said on motor power alone, and with a fair amount of legpower you could get a bit more at full throttle, but if 180W is your peak 'net' power output, your top motor speed will likely be a few mph less & you might even have to pedal a bit to reach 15mph.
PS You also might find that peak power a bit weedy if you ever did come upon a hill!
Hope that helps.
Stuart.
I agree that there are many factors which affect the accuracy of any estimate, but if its 240W power input as you say, an important factor (apologies if you already accounted for this Jeremy
) is the power loss due to inefficiency between input & output from the motor: if your motor is 75% efficient say, then 240W input amounts to about 180W of useful output motor power. Also, if that is the peak power output, i.e. 24V & 10A current limit, then the output at maximum efficiency will occur at a higher speed, and will be less power than that again (how much less & the speed difference depends on the motor, but the tongxin looks to have a smallish difference in revs/speed between the two). I'd say with around 180-190W power output at top speed you might get as much as about 16-17mph as said on motor power alone, and with a fair amount of legpower you could get a bit more at full throttle, but if 180W is your peak 'net' power output, your top motor speed will likely be a few mph less & you might even have to pedal a bit to reach 15mph.
PS You also might find that peak power a bit weedy if you ever did come upon a hill!
Hope that helps.
Stuart.
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Thanks for your input.Hi Honk
but if 180W is your peak 'net' power output, your top motor speed will likely be a few mph less & you might even have to pedal a bit to reach 15mph.
Stuart.
I have already planned for the loss of motor assistance at high speeds.
The controller will simply increse voltage to the motor until the 240W
power is reached. This will auto adjust the top RPM to match the speed
at which I am going until the 240W is being fully used.
As long as I don't abuse the motor by feeding it a lot more power than
this level it should be fine at these speeds. I'm looking for an average
speed of 20mph where I contribute by 10mph by peddeling.
Btw, I use an 28" bike. I plan to use the 24V 190 RPM Tongxin at maximum 36V
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Let us know how you get on with that configuration Honk. It's the same as the Schwinn model which has been a failure and now withdrawn, 190 rpm with 36 volts in a 700c wheel.
In that case the controller system seemed all over the place, so your experiences are going to be very interesting.
.
In that case the controller system seemed all over the place, so your experiences are going to be very interesting.
.
I spoke to Tongxin yesterday and today.
I expect to get the price and shipping on 3 hub motors next week.
Regarding the Schwinn model I can imagine the failures due to bad
controller design. In my design the controller will lower the voltage
automatically if I cannot keep up my contribution of 10mph.
But in the Schwinn the current was probably set to a higher level
and will cause a very high wattage at high voltage.
I will report my findings once the design built and is tested.
If somebody is interested I'll post the controller as well.
I expect to get the price and shipping on 3 hub motors next week.
Regarding the Schwinn model I can imagine the failures due to bad
controller design. In my design the controller will lower the voltage
automatically if I cannot keep up my contribution of 10mph.
But in the Schwinn the current was probably set to a higher level
and will cause a very high wattage at high voltage.
I will report my findings once the design built and is tested.
If somebody is interested I'll post the controller as well.
Hi Guys
I just have to remind you that my Tongxin is well on the way to 2000 miles now, and it's been faultless, very energy efficient, quiet, no resistance when pedaling, the best looking motor available, legal, I could go on, but I think you get what I'm saying. Why are some people continuing to knock possibly THE best hub motor available?
Peter
I just have to remind you that my Tongxin is well on the way to 2000 miles now, and it's been faultless, very energy efficient, quiet, no resistance when pedaling, the best looking motor available, legal, I could go on, but I think you get what I'm saying. Why are some people continuing to knock possibly THE best hub motor available?
Peter
Honk,
From my limited experience (my controller failed on the second test ride and the second one is still on its way from China), I think you'll get good performance. I would be very surprised if you have any motor slipping problems - the Tongxin generally performing well in high speed applications. I'm not sure if you are giving the motor quite enough power to give you 20mph.
I'd be very interested to hear how you get on, and would like to hear about your controller too.
I'll send you a tongxin price list if you give me your email address.
Regards,
Frank
From my limited experience (my controller failed on the second test ride and the second one is still on its way from China), I think you'll get good performance. I would be very surprised if you have any motor slipping problems - the Tongxin generally performing well in high speed applications. I'm not sure if you are giving the motor quite enough power to give you 20mph.
I'd be very interested to hear how you get on, and would like to hear about your controller too.
I'll send you a tongxin price list if you give me your email address.
Regards,
Frank
Some of us are a bit cautious at the drive slippage that has occurred with 36 volt use in larger wheels, the roller drive apparently not withstanding the startup and low speed torque. Inevitably only some motors are affected, as I'd expect with a mechanically marginal situation, but it would be foolish not to mention that this does occur on occasions.
So I don't think it's knocking, just comment on what has happened to some. I'm sure they would have liked someone to have "knocked" before they bought.
The thing we don't know is if Tongxin have made any improvements, since they don't seem to give as much information as we'd like. Hopefully they have, and I think it likely, but it would be nice to know.
.
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I have felt the "drive slippage" it only happens from a stand still, full throttle take off situation up hills, it lasts for a fraction of a second then there is full take up of power. The performance/slippage has not deteriorated over time, I have first hand experience of this motor and I have found it to be excellent, it perfectly complements my efforts at pedaling.
I'm pleased it's proving ok and lasting Peter. The benefits are undoubted, quiet drive and high efficiency of power transmission making it seem more powerful than it actually is.
You know though, just as I do, that everything moving wears. Worn gears remain in engagement, but a roller drive onto a smooth track with pressure engagement must reach a point of engagement termination. It's not knowing when that might be that makes me cautious, and the fact that it shows any sign of slip at all early in life doesn't instill confidence.
As ever, it's usage and user dependent, a bit like the Li-ion battery issue. Loads of users in the flatter areas wondered what all the fuss was about, while those of us climbing to get anywhere were tearing our hair out in frustration. I've no doubt the Nano life will have a similar relationship, lasting for ever in a low stress flatter areas, while possibly not being anything like as good in higher loading situations
.
You know though, just as I do, that everything moving wears. Worn gears remain in engagement, but a roller drive onto a smooth track with pressure engagement must reach a point of engagement termination. It's not knowing when that might be that makes me cautious, and the fact that it shows any sign of slip at all early in life doesn't instill confidence.
As ever, it's usage and user dependent, a bit like the Li-ion battery issue. Loads of users in the flatter areas wondered what all the fuss was about, while those of us climbing to get anywhere were tearing our hair out in frustration. I've no doubt the Nano life will have a similar relationship, lasting for ever in a low stress flatter areas, while possibly not being anything like as good in higher loading situations
.
I reluctantly have to remind you that I live in Wales with it's mighty hills, and my missus has a lithium ion powered bike, both our machines are to date, fine and dandy. Far be for me to say, BUT has there not been many, many posts on this forum about the problems with the Torq, I rest my case. I eagerly await your reply Tony.
I knew you were in Wales Griz, but I don't see the Torq problems as related, since it has no motor gear drive issue.
All I'm saying is that when a problem has been experienced by a few, I mention it, and it's not knocking to do that. I've done so with the Torq, with the Li-ion battery issue, with the old Panasonic unit and with many others. Therefore the Nano won't be exempt. There are many owners of Torqs and old Panasonic units who haven't had problems just as you haven't had Nano problems, so I'm just being equitable.
For example I haven't had front brake and judder problems on my Torq, nor did my Twist's Panasonic unit ever let me down, but I mention the problems in answering posts since those have happened to others.
And surely you are not saying that the li-ion batteries haven't had any issues on powerful bikes? If so you could hardly be more wrong, since even two manufacturers now admit to them and are doing something about it. Your wife's bike probably uses one of the low consumption Panasonic units I take it?
At the outset you asked why we were knocking, and I'm just showing that I'm not knocking, just reporting, nothing else.
.
All I'm saying is that when a problem has been experienced by a few, I mention it, and it's not knocking to do that. I've done so with the Torq, with the Li-ion battery issue, with the old Panasonic unit and with many others. Therefore the Nano won't be exempt. There are many owners of Torqs and old Panasonic units who haven't had problems just as you haven't had Nano problems, so I'm just being equitable.
For example I haven't had front brake and judder problems on my Torq, nor did my Twist's Panasonic unit ever let me down, but I mention the problems in answering posts since those have happened to others.
And surely you are not saying that the li-ion batteries haven't had any issues on powerful bikes? If so you could hardly be more wrong, since even two manufacturers now admit to them and are doing something about it. Your wife's bike probably uses one of the low consumption Panasonic units I take it?
At the outset you asked why we were knocking, and I'm just showing that I'm not knocking, just reporting, nothing else.
.
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