Tongxin 260 RPM power output

[andyh2]

I remember seeing somewhere that the tongxin 260 rpm motor power output is higher than other versions of the motor. The idea being that in smaller wheel applications that additional power would be fine for the motor reliability.

Am I imagining that? could anyone confirm.
Thanks.

 

[jerrysimon]

These are the only specs I have

Hangzhou Zhejiang University Tongxin Electricity Company

In addition I thought the slimmer 82mm wide ones output less power than the standard 100mm wide ones ?

Regards

Jerry

 

[wurly]

It's possible that the stator might just have a higher tolerance to burning out than the slower windings on the others, but i think what you mean is are they stronger eg the outer drive ring?
I'm running a 260rpm in a 26" wheel and the only difference i can see is the stator. All the rollers, clutch, bearings and drive ring are the same as the slower hubs. I have rebuilt it severals times and occasionally swap out the internals form one to another. I can't see any physical differances The only time i have broken the drive ring is with the 260rpm motor, so i would say no.

 

[jerrysimon]

So Mel do you have the tools and rings to repair these ?

These Tongxin motors really seem to be a niche product both sourcing them and taking them apart and fixing them.

I now have five (4 * 260RPM, and 1 * 180RPM) with three fitted in bikes 16", 20"and 26" wheels. For small, light, quiet assistance I really don't think they can be beaten.

I would not use one where I required heavy assistance or where I was using them on rough tracks.

PS wondered what sort of milage people are getting with them. I am up to about 1500 miles on my longest used ones.

Regards

Jerry

 

[flecc]

I've never seen any mention of a higher power for the 260 rpm version, only the observations of it's small wheel application being more suited to the Tongxin from both reliability and climb performance points of view.

Like Jerry, I have seen mention that the 82 mm version is lower powered, but not on a spec sheet.

 

[wurly]

Jerry
I don't have any special tools. I use a handle supplied with angle grinders, i drilled out the little tabs and replaced them with M5 bolts. It's usually enough to get the outer cover to start moving with a tap of a hammer. I use a 'press' to assemble the rollers back on to the motor shaft.
I had initially bought 2 motors from JohnP on here a few years. Since then John's had a few go wrong and my 2 motors have needed attention. With the parts left we have managed to keep ours running ok. I havn't spoken to John for a while but i know he got around 4000+miles on his Tongxin. I estimate i have 2000-3000 on mine.
My 260rpm hub is still running, the other one i replaced with a bafang. The parts from the second one is keeping the first one rollin'........and that one is on it's last life....when it finally expires, thats it.
Apart from one broken ring, i have had the hardened motor shaft break up twice. Replaceing the outer ring isn't a problem if you have a spare, replacing the motor shaft and bearings is more of a problem as it's pressed onto the aluminium rotor hence i salvage a dead motor to fix that problem.
I agree with you, when they running ok they are really good.

But i am now a convert to Bafang hubs, although a bit heavier the freewheel (once run in) is just as good as the little tongxins

 

[jerrysimon]

Thanks Mel,

Taking the motor apart is no problem I have done it several times using my DIY tool

I had to cut down the main shaft as I purchased a roller brake model in error

I meant for getting crack rings off though to date I have not had one fail. In my taking a Tongxin apart thread I added some posts on how someone took the ring off using a special tool.

The only other motor I have though about using on my Brompton if ever I run out and cannot source Tongxins is the narrow Cute Q85 motor.

When you say the "hardened motor shaft break up twice" do you mean this part ?

Not sure I fancy that happened!

Oops sorry I think hijacked the thread.
Regards

Jerry

 

[andyh2]

Thanks.

All in my mind then!

Thinking about it a Bafang 260RPM would probably be more attractive and trade the extra weight and noise for better reliability.

 

[wurly]

Jerry
The motor shaft i refer to drives the three rollers under the threaded shaft you see bolted in place here.
Considering the chinese are notorious for making bearings out of soft material i was surprise to find the motor shaft incredibly tough, until it starts to break up, then bits fall out. You will realise if this happens by the amount of noise coming from it as the rollers hit the knackered bit at high speed.
Unfortunately my hands were covered in grease by the time it was disassembled therefore i never took any photos.

You can see the crack on the outer ring. It goes through the dimples were the freewheel assembly locates.
And when you think it's a bad design and it going to crack there again. This happens....it cracks somewhere else on the other side.

Tongxins are great, but don't expect high mileage, you maybe lucky though.
I'm fitting Bafangs now for more reliablity.

 

[kitchenman]

PS wondered what sort of milage people are getting with them. I am up to about 1500 miles on my longest used ones.

I'v done about 4500 miles with mine (175 rpm version). Had it serviced once by Cytronex to cure a freewheel issue.

 

[jerrysimon]

Thanks Alan. Thats good to know. The owner/Cytronex poster here claimed he had one that had reached 7000 miles.

Mel I see now the little shaft I had shown was the hollow one on the other side. Unless mine and my spares all fail in the next 12 months then I will continue to stick with Tongxin.

In my application of mainly small wheeled portable bikes, this motor is perfect. Most of my use is on a pretty flat commute and just gives me help when its windy or I am feeling lazy, so fingers cross I should see a higher milage than many before failure.

Regards

Jerry

 

[kitchenman]

Jerry, is the 260 rpm model the same size as my 175 rmp? Just wondering if my hub adapter collar is going to fit other Tongxins (assuming it doesn't already support disc brakes) ...

 

[Scottyf]

On that post earlier they look the same on the data sheet. Just one is wound differently.

 

[kitchenman]

On that post earlier they look the same on the data sheet. Just one is wound differently.

Thanks Scott (my work security denied me access)

 

[GT3]

I bought two Tongxin 260rpm motors from Frank on here in April 2009. Frank had used them both, and I had another 4,000 miles from the first. When the first failed I fitted the second, which lasted less than 100 miles. Fault on both was the magnets breaking away. I reattached with epoxy but it has failed again after another 500 miles. I'm stripping it tonight.

In response to the OP, I find they have ample power and achieve nearly the velocities I saw with my first 1000W kit. In contrast, I bought a Bafang when the second Tongxin failed which is a big disappointment. On the third day I used it, I had the unprecedented experience of being overtaken by a unassisted cyclist. It came off that night.

 

[Scottyf]

What are you doing to the poor little motor's for them to be able to keep up with 1000w kits?
You must be seriously over powering them in order to get similar performance.

To be honest looking at pictures of Cute / Tongxin and Bafang they all look very similar and quality probably depends on how fine the tolerance's have been when they exit the factories.

If your after a motor thats more dependable then you should really look into the Ezee motors which as far as I know. Have taken the original concept and then improved it with some swedish trickery and engineering. Expensive... Yes maybe. But a better design and build all round.

If the tongxin motors are of similar size. With similar magnets and copper fill. Then they will have the same power and saturation points.

 

[Deleted member 4366]

In response to the OP, I find they have ample power and achieve nearly the velocities I saw with my first 1000W kit. In contrast, I bought a Bafang when the second Tongxin failed which is a big disappointment. On the third day I used it, I had the unprecedented experience of being overtaken by a unassisted cyclist. It came off that night.

Bafangs, like Tongxins, come in different speed versions. I doubt that you were comparing like with like. My 24v Cyclamatic with Bafang will do 32mph using a 44v lipo pack and 36v controller with the shunt soldered for 20a. There's no way a Tongxin will do that without exploding.
Generally, based on anecdotal evidence from the various forums, Tongxins are smother and quieter, and Bafangs are stronger and more robust. Both give approximately the same power with the same winding and controller, but the Bafang can be made to give more power without self-destructing

 

[Scottyf]

A bit off topic but I'd wish someone would compare the larger geared motors of the likes of BPM vs Mac vs Puma vs Cute.
I doubt there is much in all of the larger ones though.

To be honest there shouldn't be much ever going wrong with them if kept to normal rated powers. After all. Electric motors are very very simple and its really only the build quality that differs between them.

 

[jerrysimon]

Jerry, is the 260 rpm model the same size as my 175 rmp? Just wondering if my hub adapter collar is going to fit other Tongxins (assuming it doesn't already support disc brakes) ...

Alan I think they are available in both 100mm and 82mm widths in all the different RPM options. All mine 4 * 260RPM and 1 *190RPM are 82mm wide ones.

As yours is a Cytronex one I suspect it is the 100mm wide model.


Regards

Jerry

 

[amigafan2003]

I'd pay good money for a 100mm wide 260rpm motor.

What's the axle width like on the 83mm ones? Room for some spacing washers to fit to a 100mm fork?