My Tongxin kit bike
- Thread starter frank9755
- Start date
M
mk1
Guest
Looks good Frank. It just goes to show that if you use a bike made with quality steel tubing, instead of aluminium drainpipes with gussets everywhere. You can achieve a comfortable ride without the need for suspension.
Martin
Martin
Chantelauze,
As far as I know, Tongxin just make the motor and controller, I don't think they make complete bicycles.
Asking them to promise particular bicycle performance is really a bit unfair, as they can have no control over the components anyone may use when building a complete bicycle.
Tyres vary a great deal in rolling resistance, from size to size, manufacturer to manufacturer and most importantly, from varying tyre pressure. Similarly other cycle parts also absorb power to some extent, depending on stiffness, freedom to rotate etc. Even the frame stiffness will have an effect.
Battery type, capacity and operating temperature also has a major impact on performance, even between batteries of the same chemistry. You can see the effect of this on the ebikes.ca simulator, which tries to model the effect of different battery types, with differing internal resistance and losses.
The only way to obtain accurate and valid data on performance is to undertake tests under controlled conditions. This is difficult and it's unlikely that anyone would get the same results on another bicycle, even fitted with exactly the same components.
The best you can hope for is a theoretical estimate of the very best performance you might get, and then expect to get no more than about 80% of this in practice. Assuming that you will get the theoretical motor maximum speed is very misleading, as you most probably won't. This isn't a Tongxin issue, it applies to all motors that I've looked at. They all give maximum speed/rpm figures that are significantly greater than could be achieved when the motor is subject to a load.
Performance prediction, or measurement, is difficult, which is why so many electric bicycle specifications seem to be either a bit vague or are at best just advertising claims. For example, A to B magazine reviewed the Tongxin motor fitted to a Brompton folder. They obtained a ridiculously big range, but most believe that this was due to the tester inadvertently pedalling more than he would have on another type of bicycle, perhaps because the Tongxin motor has such a low drag when unpowered.
Fitting any motor kit to a bicycle is going to be an experiment. If the bicycle is being sold ready-built as an electric model, then I would hope that the manufacturer has done all the experimentation before marketing it. Unfortunately, for those of us making do-it-yourself electric conversions, we have to do our own experiments!
Jeremy
As far as I know, Tongxin just make the motor and controller, I don't think they make complete bicycles.
Asking them to promise particular bicycle performance is really a bit unfair, as they can have no control over the components anyone may use when building a complete bicycle.
Tyres vary a great deal in rolling resistance, from size to size, manufacturer to manufacturer and most importantly, from varying tyre pressure. Similarly other cycle parts also absorb power to some extent, depending on stiffness, freedom to rotate etc. Even the frame stiffness will have an effect.
Battery type, capacity and operating temperature also has a major impact on performance, even between batteries of the same chemistry. You can see the effect of this on the ebikes.ca simulator, which tries to model the effect of different battery types, with differing internal resistance and losses.
The only way to obtain accurate and valid data on performance is to undertake tests under controlled conditions. This is difficult and it's unlikely that anyone would get the same results on another bicycle, even fitted with exactly the same components.
The best you can hope for is a theoretical estimate of the very best performance you might get, and then expect to get no more than about 80% of this in practice. Assuming that you will get the theoretical motor maximum speed is very misleading, as you most probably won't. This isn't a Tongxin issue, it applies to all motors that I've looked at. They all give maximum speed/rpm figures that are significantly greater than could be achieved when the motor is subject to a load.
Performance prediction, or measurement, is difficult, which is why so many electric bicycle specifications seem to be either a bit vague or are at best just advertising claims. For example, A to B magazine reviewed the Tongxin motor fitted to a Brompton folder. They obtained a ridiculously big range, but most believe that this was due to the tester inadvertently pedalling more than he would have on another type of bicycle, perhaps because the Tongxin motor has such a low drag when unpowered.
Fitting any motor kit to a bicycle is going to be an experiment. If the bicycle is being sold ready-built as an electric model, then I would hope that the manufacturer has done all the experimentation before marketing it. Unfortunately, for those of us making do-it-yourself electric conversions, we have to do our own experiments!
Jeremy
Frank,
Your bike looks very neat indeed, congratulations on making it such a tidy job. At a casual glance it doesn't look like an electric bike at all, which is just what I aim to achieve with my 'bent conversion now.
By the way, if you edit the picture URLs by deleting the "?v=0" at the very end of each one, they will appear embedded in the post, rather than as links. I found this out by trial and error a few days ago!
Jeremy
Your bike looks very neat indeed, congratulations on making it such a tidy job. At a casual glance it doesn't look like an electric bike at all, which is just what I aim to achieve with my 'bent conversion now.
By the way, if you edit the picture URLs by deleting the "?v=0" at the very end of each one, they will appear embedded in the post, rather than as links. I found this out by trial and error a few days ago!
Jeremy
Thanks, Martin and Jeremy, for your comments! I'm pleased with how it looks.
One question - has anyonen spotted where the controller is?
Also thanks, Jeremy, for the advice on photos - I was wondering how to do that!
I agree completely with your comments on kits and what information it is reasonable to expect before commencing the experiment!
Frank
One question - has anyonen spotted where the controller is?
Also thanks, Jeremy, for the advice on photos - I was wondering how to do that!
I agree completely with your comments on kits and what information it is reasonable to expect before commencing the experiment!
Frank
M
mk1
Guest
Not quite...but good idea, Jeremy!
If you look closely at the top picture on this page with a close-up of the panniers, it is sticking out of the front of the pannier nearest the camera, near where the wires go in to the pannier. It's inside an old black sock which is attached to the pannier with a safety pin! Being black on black it is next to invisible. I originally left it inside the pannier but it got a bit warm so I came up with this arrangement to let it cool without looking too indiscreet.
Frank
If you look closely at the top picture on this page with a close-up of the panniers, it is sticking out of the front of the pannier nearest the camera, near where the wires go in to the pannier. It's inside an old black sock which is attached to the pannier with a safety pin! Being black on black it is next to invisible. I originally left it inside the pannier but it got a bit warm so I came up with this arrangement to let it cool without looking too indiscreet.
Frank
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TongXin motor & side accessories
Frank
as you say : it's an invible controller
did you recieve it as from attached photo + the spokes fitted to yr size of wheel ( my spokes were not the appropriate ones when i ordered 3 years ago...)
Frank
as you say : it's an invible controller
did you recieve it as from attached photo + the spokes fitted to yr size of wheel ( my spokes were not the appropriate ones when i ordered 3 years ago...)
Attachments
yes the two samples were in good working conditions
they did not last very long due to mistreatments on my side , but TongXin is nor to held responsible for it
i also remember a smooth ride and totally silent , but the maximum mileage was rather poor in consideration of a large capacity lithium cobalt battery pack i used at that time ( 3 years ago )
they did not last very long due to mistreatments on my side , but TongXin is nor to held responsible for it
i also remember a smooth ride and totally silent , but the maximum mileage was rather poor in consideration of a large capacity lithium cobalt battery pack i used at that time ( 3 years ago )
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Looks good Frank & I hope it works well for you 
.
Which controller have you used - is it 36V 15A? In which case it wouldn't be legal in Australia if their limit is 200W?
To estimate the top speed (flat & no wind) from the motor rpm and wheel size, I find it can usually be estimated quite closely by taking the rpm for a given voltage eg 260rpm @ 36V, then allowing for the actual battery voltage, say ~42V for a 36V NiMH, multiply the rpm by that factor of 42/36, or 7/6 to get around 300rpm for that motor, then the max unloaded wheel speed can be calculated from the wheel circumference - so about 24mph no-load speed. Then the top speed on the road can be estimated from the intersection on a graph of power vs speed of the 2 curves: one for the motor and one for the 'bike & rider' - gives about 20mph for an average upright bike without pedalling, 22-23mph with moderate pedal input added to the motor power curve.
Stuart.
.Which controller have you used - is it 36V 15A? In which case it wouldn't be legal in Australia if their limit is 200W?
To estimate the top speed (flat & no wind) from the motor rpm and wheel size, I find it can usually be estimated quite closely by taking the rpm for a given voltage eg 260rpm @ 36V, then allowing for the actual battery voltage, say ~42V for a 36V NiMH, multiply the rpm by that factor of 42/36, or 7/6 to get around 300rpm for that motor, then the max unloaded wheel speed can be calculated from the wheel circumference - so about 24mph no-load speed. Then the top speed on the road can be estimated from the intersection on a graph of power vs speed of the 2 curves: one for the motor and one for the 'bike & rider' - gives about 20mph for an average upright bike without pedalling, 22-23mph with moderate pedal input added to the motor power curve
.Stuart.
Yes, that's right. It can deliver a decent peak output, but is rated as 180W continuous output so the Aussies would be happy. It is marketed in Australia as a legal option. I know it's not giving more than 15A as I've added a 15A fuse as an extra safeguard, and it hasn't popped!
In this case that is pretty accurate! If I lift the wheel off the ground and spin it, it goes up to 25-26 mph. I've not tried it under load without pedalling, but 22 mph with pedalling is very achievable.To estimate the top speed (flat & no wind) from the motor rpm and wheel size, I find it can usually be estimated quite closely by taking the rpm for a given voltage eg 260rpm @ 36V, then allowing for the actual battery voltage, say ~42V for a 36V NiMH, multiply the rpm by that factor of 42/36, or 7/6 to get around 300rpm for that motor, then the max unloaded wheel speed can be calculated from the wheel circumference - so about 24mph no-load speed. Then the top speed on the road can be estimated from the intersection on a graph of power vs speed of the 2 curves: one for the motor and one for the 'bike & rider' - gives about 20mph for an average upright bike without pedalling, 22-23mph with moderate pedal input added to the motor power curve
Yes & I meant to say that your rough calculation works equally well Frank - quicker too!
The Aussie authorities seem easily pleased then - slap in a motor rated for 200W & run it well over 20mph (when its likely using rather more than 200W), sounds good! (unless you have hills!).
PS The motor gearing in your 700c wheels is virtually identical to a Torq1 whose motor is also nominally 260rpm I suspect.
Stuart.
The Aussie authorities seem easily pleased then - slap in a motor rated for 200W & run it well over 20mph (when its likely using rather more than 200W), sounds good! (unless you have hills!
).PS The motor gearing in your 700c wheels is virtually identical to a Torq1 whose motor is also nominally 260rpm I suspect
.Stuart.
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Yes Stuart - I'm happy to admit that is where I got the idea from. Ezee put the motor geared for the Quando into a full size wheel so I just took the one that had been used as the Brompton Nano, in the same size wheel as a Quando, and put that in a full-sized wheel!
Of course the point I keep coming back to is that the key difference between my bike and a Torq is that it enables the rider to contribute much more because it has the cycling quality of a decent-quality normal bike. To illustrare, for leisure riding I normally use a non-powered bike, and at the moment, this one is having to double up. So on Saturday I did a 20 mile section of Sustrans Route 4, from Maidenhead to Reading, which features a c.2mile / 100 m climb up an unsurfaced bridleway. People say the Torq is not bad to ride without motor but I would be surprised if anyone would take it on such a ride! I would certainly not fancy getting my Wisper up that hill without power.
Frank
Of course the point I keep coming back to is that the key difference between my bike and a Torq is that it enables the rider to contribute much more because it has the cycling quality of a decent-quality normal bike. To illustrare, for leisure riding I normally use a non-powered bike, and at the moment, this one is having to double up. So on Saturday I did a 20 mile section of Sustrans Route 4, from Maidenhead to Reading, which features a c.2mile / 100 m climb up an unsurfaced bridleway. People say the Torq is not bad to ride without motor but I would be surprised if anyone would take it on such a ride! I would certainly not fancy getting my Wisper up that hill without power.
Frank
Yes - sorry - it's a few months since I thought it all through so I'd forgotten some of the details.
That has jogged my memory. My thinking went that given the Torq motor is more powerful, the fact that mine was that bit more overgeared meant I might get a similar speed, but would be that bit less able to climb the steeper hills - which was not a priority for me.
That has jogged my memory. My thinking went that given the Torq motor is more powerful, the fact that mine was that bit more overgeared meant I might get a similar speed, but would be that bit less able to climb the steeper hills - which was not a priority for me.
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