New Super Light Tongxin Motor Design/Kit

[laroche]

Jerry

Right on! Go for it!

I bet the 80mm version is 1.4kg or pretty near that; mine are 1.6kg (excluding nuts and washers). What RPM have you gone for?

I've just received a reply to my query about the pedal sensor. It glues (no kidding!) underneath the bottom bracket and detects rotation in the magnet disc on the axle. This arrangement gives me a problem. I had my eye on a carbon frame, but they tend to be slightly bevelled between the ends of the bb shell and I'm not sure it will be possible to position it properly.

Here's the diagram I sent to Sky Zhang as a guess as to how it's installed. She replied that it was correct, though I suspect a little fiddling about may be required to get it dead right. (Hope the picture shows up OK)



I also suspect it's the planned Cytronex kit; can't help feeling Mark Searles' fingerprints are all over the thinking behind this.


cwah

I cannot help thinking this is the worst kit there is for over-cooking, either by installing it in too big a wheel or over-volting. The whole thing is seriously titchy - skinny cables and connectors included. I wish you the very best of luck!

Cheers!

 

[Pedalo]

I'd thought I'd given up on elctric assistance having now riden unpowered for a year or so but all this talk of new fangled lightweight kit might just cause me to fall off the wagon!

I'm trying to work out how the wiring is connected up. If the controller is within the motor then am I right in thinking that all wires from the battery, the handlebar controller and the pedelec sensor all come together at a single connector at the motor? The handlebar control looks to have a continuously variable control from low to high. Is there also an 'on/off' switch at the handlebars?

 

[jerrysimon]

I went for a 260RPM one for my 16"/20" wheels.

I agree its hard to understand how it all connects up, though as I said my motor does not have an internal controller just a normal three phase power supply plug.

As I am a thumb throttle junkie this is quite a departure for me, though I am hoping that by using pedelec and varrying the power to assistance by using the boost rate regulator (if I understand it correctly) I can then provide more or less assist depending on how much exercise I want.

Regards

Jerry

 

[laroche]

Pedalo + Jerry

Yes, three cables (battery, sensor and handlebar control) join up near the motor in a single nine-pin connector. The sensor and handlebar control cables are also each divided with another smaller connector.

The cables seem an appropriate length and well put together. They should make up into a very neat set-up. If this thing does what it says on the tin it will be the dogs ****** of minimalism. Here's a crude layout of the wiring.



The sensor cable has 3 wires and the handlebar control 4.

There's no on/off switch. I'm hoping extreme 'low' will be off. If it isn't, I'll fit a switch myself; otherwise it will be impossible to ride unassisted.

I do not know exactly what that sliding control does. It's sticky; it stays in position until shifted. I'm hoping it does what a stiffened-up thumb throttle would do - ie set a variable target speed, activated by turning the pedals. That seems to me the very best set-up possible for an electric bike. I like the target speed operation on my Cytronex Trek - but there are only two pre-set speeds available and they're both quite fast. If the mind of Mark Searles really is behind this kit, I would bet it is indeed a speed control. That would also suggest 'Low = Off'.

Incidentally, the numbers on my two motors are LDT00001 and LDT00002. Sales so far don't seem to have been too good!

Cheers!

 

[laroche]

The 9 pin connector is like this:

A pair of 9Pin Waterproof Male/Female Connector Cable for Motor - BMSBATTERY

Ignore the cable configuration. Only the connector is the same

 

[jerrysimon]

Laroche,

Some one on here (I forget who) sourced those connectors for us to use on our current systems.

Keyde just replied and told me the stepless 5 speed display does regulate pedelec assistance. Not sure if as you say low is "off".

Unfortunately the smaller lighter v motor I have ordered without the internal controller, does not support this regulator unit. The controller they are sending me is a new version which they claim is a new more effective model developed for these motor. Its amazing what they tell you in correspondence before you place the order. Despite what you ask they never volunteer information. I may even end up with just another expensive stock Tongxin motor

It will be interesting to see when it all arrives lol

Regards

Jerry

 

[laroche]

Jerry

Blimey! No regulator? Then, presumably, the motor responds to cadence(?). If so, how do gears fit in to that? If I am not mistaken the later Cytronex bikes had no handlebar control, just a switch which started the motor and accelerated the bike "up to speed" - a meaningless phrase which may or may not have something to do with cadence or may just mean full speed.

A "new version"? Judging by the numbers on my motors (1 and 2!) they haven't sold any of the old version!

What does "pedelec assistance" mean anyway? What exactly happens when it varies? What does it feel like? I've read the phrase many many times, but never understood it.

I feel a long saga is unfolding before us...

Keep the faith!

Cheers!

 

[jerrysimon]

Laroche,

When they say new controller I understood them to mean one specific for these new light/smaller motors.

I have not ridden a bike with a pedelec sensor. As I understand as soon as you turn the crank the motor begins to cut in. Worth reading this.

I am sure others will chip in, but I assume the faster you turn the crank the more assistance you get. Hence in a lower gear when climbing a hill, you have to keep revolutions up to maintain the most assistance.

This regulator is like the three step power buttons you see and I assume control the overall amount of help the motor supplies when it senses the crank revolutions.

I have ordered quite a few bits from China and in the past have received stuff that was not quite like I thought it was going to be.

This happened when I ordered a roller brake motor once in error and it had an extra long drive shaft on one side and the case had a huge boss on one side to take the roller brake.

In most cases you can modify stuff. In this case I learned how to take the motor apart, hack the outer case and shorten the shaft to fit my Brompton

At worst, I will just connect this smaller motor up to one of my existing low current Tongxin controllers and use throttle only. With the Tongxins I never apply throttle until the bike is moving as experience from these forums indicates that these lower power/lighter motors have to be treated with a little care. I also had one of the earlier Cytronex bikes where there were just two buttons. One to switch power on/ off and one that you pushed once for half speed and again for full speed. I actually quite liked it and as I said I always made sure the bike was rolling before I hit the power on button.

Regards

Jerry

 

[daniel.weck]

Hi Jerry (et al), these new mini-motors are exiting!

By the way, I use a dual control method on my Brompton-Tongxin: thumb control for quick starts off the mark (junctions, traffic lights, etc.), and pedal assist sensor for normal use (and yes, you must keep the cadence up when going up hill, so I drop a gear or two on my 6-gears Brompton).

The 3-way switch regulates the power threshold: the two low-power settings are very useful (safer) for when riding really slow (e.g. in a traffic jam, in a supermarket car park, or amongst pedestrians), otherwise the high-power setting is nearly always the best choice.

Cheers, Dan

 

[jerrysimon]

Hello Dan

Nice to see you posting and thanks for the clarification.

Regards

Jerry

 

[cwah]

Had a conversation with them:
me:
"If I limit to 400RPM could that be ok? And I suppose it would be the gear that may be damaged over time, maybe if I get spare gear it could last?"

him:
"Our motor adopts the technique of gearless, so the motor is rather quiet when it runs. Actually we suggest clients to limit the rotating speed within 260rpm. And we can offer your a guarantee period of 2 years."

The motor is gearless? I'm not sure to understand. Does that mean it's a direct drive motor?

 

[jerrysimon]

The motor is gearless? I'm not sure to understand. Does that mean it's a direct drive motor?

It uses smooth steel roller bearing/gears.

Check out this link for more internal pics.

I wonder if the two year guarantee is genuine. Problem as always, is if they want you to return the motor back to China then postage each way would make it pointless.

Regards

Jerry

 

[cwah]

So it's a geared motor. Not sure to understand what he meant by "technique of gearless"..

And of course I don't really believe on their warranties neither.

 

[jerrysimon]

There's no on/off switch. I'm hoping extreme 'low' will be off. If it isn't, I'll fit a switch myself; otherwise it will be impossible to ride unassisted.

Laroche I have just looked at the PDF that flecc hosted for me when I posted in the first few threads. It gives full details of the kit. The good news is it states that the regulator (they call it a "boosting rate regulator" lol) does control power from 0-100% so, looks like you will be able to turn it off

Regards

Jerry

 

[laroche]

Jerry

I'd seen that 'boosting rate regulator' on the brochure and forgotten about it; perhaps it just seemed a bit too vague. But less so now. Thanks for the explanation of what it does. I think I get that now. I like Daniel's 'power threshold' phrase.

As for the pedal sensor, we shall just have to see..... The fitting and operation of this tiny, but so vital, component will present a few bridges to cross I think.

Cheers!

 

[laroche]

A rather important issue....it's that pedal sensor again.

The problem is one of incompatibility between the magnet disc and modern bottom brackets.

The magnet disc has an external diameter of 40mm, an internal diameter of 15mm (could be expanded to maybe 17mm but no further) and is 6mm thick.


Cartridge Bottom Brackets

So far as I can tell, this thing will fit on a cartridge bottom bracket with a square taper; that's the one on the left in the pic below The diameters of the others seem too big.




External Bottom Brackets

I doubt the sensor will fit on a bike with an external bottom bracket; the cranks always seem to sit too close to the BB for a 6mm wide disc to fit comfortably between them. Viz:




'Pressfit' Bottom Brackets

These require the BB shell to have an internal diameter of 46mm, perhaps 48-50mm external. This would surely mean the sensor would be too far away from the magnets to work (see my earlier diagram of the disc).

What this means is the disc will not fit (or, at least, not without grief) almost any modern uppish market bike, say £500+. All the big manufacturers have shifted all or part of their branded class production in at least one of the above ways in recent years. Eg, the disc will fit on my 3 year old Trek FX7.3, but would not fit on the new version which has an external bottom bracket.

Bike experts may know more and may have better news. But I doubt this is a 'fit any bike' kit.

I remain optimistic.............

Cheers!

 

[jerrysimon]

I may just use the motor with an existing Tongxin controller and throttle assuming it is rated the same.

Regards

Jerry

 

[laroche]

Jerry

I should stress it will fit most, if not all, square taper cartridge BBs. There are lots of bikes still use this tackle, but very few upmarket models (almost all use externals now). Exceptions include the Moulton TSR2(!)

Cheers!

 

[nigelhealy]

As with all Tongxin motors these are not power units but light e-assist. Perfect for lightweight setups which I am fond of.

Does this mean it can't keep a decent speed on its own?

 

[jerrysimon]

On the flat it will do whatever speed its RPM is rated for, given the size of wheel rim used.

For me I use a 260RPM unit in 16" and 20" rims so that is 15mph and 16.5mph respectively.

BTW Nigel welcome to the forum I think I recognise you from the Brompton or Moulton forums.

Regards

Jerry