Sourcing Tongxin and other components from China

[frank9755]

All these speed are for a maximum of 20 kph rather than 25kph so all a bit low.

This is what Tongxin specifies - probably based on the Chinese market (?) - but we all overgear to get higher speeds.

If I work out the motor required for my cytronex I get a figure of 192 rpm but that may be that I am not working out the wheel diameter very accurately. However it would perhaps explain why my bike rarely pulls me up to 15mph - more like 14mph.

More likely to be the slightly lower voltage of the NiMH battery. My 175rpm Tongxin in a 700c wheel assists to a bit over 16mph with a Ping LiFePO4.

 

[AndyOfTheSouth]

Hi Frank

Thanks for the link - apologies for missing it. I emailed Keywin and received an impressively fast response. He can supply the controller for $45 included shipping, but only the Bafang SWXK sensorless motor (180 RPM), not the Tongxin. This may be what I already have (I don't actually know) and am trying to fix. However, not only is it bigger and heavier than the Tongxin, it has rolling resistance.

Best wishes

Andy

Correction: have now googled Bafang SWXK and it looks different from the Bafang I have. It looks smaller and more Tongxin-like! Interestingly, it shows a cable with a local connector - an obvious idea and very practical, but strangely absent from mine.

The link is Suzhou Bafang Electric Motor Science-Technology Co.,Ltd.

I will try to find out more about it.

 

[flecc]

Andy, that 8fun motor is the latest version of the motor used in the eZee Torq 1 and Quando bikes. It's main difference is the stationary side plate centre with large diameter bearing allowing a side entry cable instead of spindle entry, rather like the system Heinzman use. It will still have the rolling resistance of the nylon gears though. About a half kilo heavier than the Nano and slightly bigger.
.

 

[HarryB]

This is what Tongxin specifies - probably based on the Chinese market (?) - but we all overgear to get higher speeds.



More likely to be the slightly lower voltage of the NiMH battery. My 175rpm Tongxin in a 700c wheel assists to a bit over 16mph with a Ping LiFePO4.

Well a back of an envelop calculation I work out that for a 175rpm motor to be correct then the wheel diameter has to be 750mm. I think you have to have some balloon tyres to get up to that sort of diameter. A 700c wheel is 700mm when it has a 700X39 tyre on it but the cytronex have 700X32 tyres so less than 700mm.

So my calculations are:

192.19=25x1000/60x3.142x0.690


I can only assume that the calculation is based on a nominal voltage of 36V unless somebody can tell me where else I can be going wrong?

 

[AndyOfTheSouth]

In case any of it is of any use to anyone, here are the details of Bafang motors from Keywin Ge (ecrazyman@gmail.com).

SWXK motor price is $185 included shipping, the motor and controller are bought together, the total price is $215.

SWXK is the front motor for 26" wheel - Keywin can install disc brake but not a freewheel.

The rear motor model is SWXH – he can install a standard seven speed freewheel and disc brake but not the freewheel.

The price for either is $175 included shipping.

The motor is 36v/250w. If needed he can add pedal sensor feature for the controller.

I have simply taken these details from emails he sent me (very promptly). I have no idea about their value, etc.

 

[daniel.weck]

here are the details of Bafang motors from Keywin Ge (Keywin@eCrazyman.com).

I think his email address is Ecrazyman@gmail.com (Ecrazyman.com is not a valid domain name). Anyway, the best is to contact him via his eBay outlet (I'm waiting for his reply regarding a Bafang motor).

Cheers, Dan

 

[AndyOfTheSouth]

Thanks Dan, I did indeed email him on ecrazyman@gmail.com. He responded more or less instantly. I must have been dozing when I wrote the other address. Have now corrected it - thanks!

 

[daniel.weck]

Thanks Dan, I did indeed email him on ecrazyman@gmail.com. He responded more or less instantly. I must have been dozing when I wrote the other address!

I'm waiting for his reply.

On a positive note, I've actually just received a reply from Suzhou Bafang (Helen from the sales department), I'm thinking of purchasing a kit direct from them, and Helen doesn't seem to tick so far that I am not going to buy in bulk (I'm not a trade / reseller)...we'll see. In the meantime, I can ask for technical details about their newest motors.

By the way, I just got the "8-Fun" meaning: 8 is "Ba" in Chinese, so 8-Fun = Bafang !

Cheers, Dan

 

[flecc]

By the way, I just got the "8-Fun" meaning: 8 is "Ba" in Chinese, so 8-Fun = Bafang !

Cheers, Dan

That's right! The number 8 is the luckiest number in China, and luck is more important a factor to Orientals than to us. The electronics company LG for example is actually the Lucky Goldstar company.

And "fun" needs no explanation of course.
.

 

[daniel.weck]

It seems that the Tongxin 24V 180W 80mm (260rpm for 16"20" wheels) can be purchased from Germany (no extra tax, straight-forward Europe shipping):

Google Translate

(some info there about the Suzhou Bafang 8-Fun SWXK as well)

 

[winterdog]

It seems that the Tongxin 24V 180W 80mm (260rpm for 16"20" wheels) can be purchased from Germany (no extra tax, straight-forward Europe shipping):

Google Translate

(some info there about the Suzhou Bafang 8-Fun SWXK as well)

what a wonderful page thank you

 

[daniel.weck]

what a wonderful page thank you

You're welcome. Pedelec.de also has a nice wiki page for the Tongxin:

e-motor:tongxin [Wiki Pedelec-Forum]

 

[daniel.weck]

I'm very curious about the "FWF" motor that these german riders seem to like even more than the Tongxin. Just like the Tongxin, it's a totally different technology than the usual geared brushless motors (Suzhou Bafang / 8-Fun, etc.). It's not a high-power motor (so it shouldn't slip unless it's really under stress), but seems to provide discrete torque under pedal-assist...if only I could speak German better than Google-Translate !

 

[daniel.weck]

FYI: Frank (the seller) has got Suzhou Bafang (8-Fun) SWXK units in stocks (36V 250W 255rpm), and Tongxin (24V 180W 260rpm). The FWF is not available. He normally adds 12 Euros for postage, but it might be a little more for UK delivery.

It seems that the Tongxin 24V 180W 80mm (260rpm for 16"20" wheels) can be purchased from Germany (no extra tax, straight-forward Europe shipping):

Google Translate

(some info there about the Suzhou Bafang 8-Fun SWXK as well)

 

[daniel.weck]

There's also a french supplier for the latest Bafang (they call it "Vicky"):

Moteur Vicky Avant avec jante alu double paroi - Vue détaillée de l'article - www.ebike-discount.com

Cheers, Dan

 

[daniel.weck]

Or directly from China:

Bafang QSWXK-Front E-Bike DC Brushless Motor 150~250W on eBay (end time 02-Oct-09 01:21:25 BST)