New Keyde rear roller motors

[docnjoj]

I just saw these and have e-mailed for information. They are geared at 17:1 so they may be powerful enough to get me up some 4-5% hills that are around here. I don't know if they are all internal throttle and sensorless but I prefer sensored so I can use my old Infineon or analogue Crystalite. Any suggestions would be welcomed. These are apparently cassette and 135 mm rears.
otherDoc

 

[ohzee]

http://www.keyde.com/?do=product&lang=en&event=view&ids=11

that what your talking about ?

Never seen those before.

 

[Drunkskunk]

Rollers instead of gears? those look interesting. Might not take much power but I bet it would be quiet

 

[amberwolf]

Rollers instead of gears? those look interesting. Might not take much power but I bet it would be quiet

Yes. See here:
http://endless-sphere.com/forums/viewtopic.php?f=2&t=25188
and other TongXin threads.

 

[bbbelanger]

Don't be confused...The rollers they are referencing are roller brakes (see the spline on the side or look at the front wheel options.
Believe me, you don't want roller brakes on a high power eBike : don't ask me why I know...talk about emergency foot braking !
Roller brakes are fine in flat country but if you have real hills on your path they can get scary!

 

[Jeremy Harris]

Don't be confused...The rollers they are referencing are roller brakes (see the spline on the side or look at the front wheel options.
Believe me, you don't want roller brakes on a high power eBike : don't ask me why I know...talk about emergency foot braking !
Roller brakes are fine in flat country but if you have real hills on your path they can get scary!

No one here is confused. These motors use roller planetary "gears" for the reduction, an innovation that Tongxin came up with a few years ago for quiet low power motors. Keyde are using the same technology, essentially an interference fit set of sun and planet rollers inside a hardened steel ring as the reduction drive. It works OK, but only for limited power, as the rollers tend to slip slightly at very high torque loads. There were also some reliability issues with the original Tongxin design, which is probably why they have been redesigned when production was taken over by Keyde.

Roller brakes are something completely different, but some motors do have the option for fitting them, as they are popular on low power ebikes in the Far East, I believe.

 

[docnjoj]

http://www.keyde.com/?do=product&lang=en&event=view&ids=11

that what your talking about ?

Never seen those before.

Yep! Those be they!
otherDoc

 

[docnjoj]

I just heard back from Ms Sky Zhang of Keyde and she states that the motors have 17:1 "planetary gears". I'm not sure if this is a communication gap but I wrote back and asked if the "gears" were, in fact rollers. Also she says they cannot be used with a thumb throttle but only Pedalec? Stay tuned, folks. She also says there are none with Halls so they are all sensorless. Hmmmm.............
otherDoc

 

[amigafan2003]

I just heard back from Ms Sky Zhang of Keyde and she states that the motors have 17:1 "planetary gears". I'm not sure if this is a communication gap but I wrote back and asked if the "gears" were, in fact rollers. Also she says they cannot be used with a thumb throttle but only Pedalec? Stay tuned, folks. She also says there are none with Halls so they are all sensorless. Hmmmm.............
otherDoc

She might be talking about the motors with inbuilt controllers - they are pedelec only.

I'm using one of the normal motors with a thumb throttle and I can confirm they are very quiet and free rolling - just like a tongxin. Will only tolerate about 500 watts though and throttling on from a standstill induces clutch slip. It's truly an assist motor.

 

[d8veh]

If you want a throttle, don't use the Keyde controllers because they all require that you're pedalling before the throttle operates, and if you stop pedalling, the throttle stops.

 

[docnjoj]

If you want a throttle, don't use the Keyde controllers because they all require that you're pedalling before the throttle operates, and if you stop pedalling, the throttle stops.

Yeah that would be a problem. I have a sensorless controller but it seems in the Keyde ads all the motors have a built in controller. Zhang did write bck and confirm the rollers. If I can get one without the in-built controller I will order it.
otherDoc

 

[melodious]

I looked at the keyde website because they offered the rare 80mm motor that would fit my bike's front fork. After looking at the pricepoints for their motors, it didn't take me long to find other cheaper alternatives. FWIW, the 80mm keyde front hub motor is priced a little under $800 and that's not including a battery. Being only a pedelec motor, only proves that this motor, at a standstill, lacks any amount of torque without you helping via peddling. That's fine for many who use their legs anyways, but a bit of an inconvenience for others who want the power when they want it. What really is nice about this motor is it's small footprint. It's barely noticeable unless you know what it is.

 

[docnjoj]

Hmmm......melodious. I just checked their E-bay site and the $800 is for the full kit including a bottle battery and a controller plus Pedalec stuff. They list the motors at about $300 but that too is with the controller. I am waiting for a quote from Zhang for just a bare motor but 135 mm rear. I guess it is possible for the 80mm one to be much more expensive, but I don't see how? The new rears have very low gearing at 17:1, so perhaps it will tolerate some startup torque. It will be a grand experiment for me since tha last one I got about 10 years ago lasted 4.5 miles and then self destructed. Am I a glutton for punishment or what?
otherDoc

 

[melodious]

What's wrong with a Mac/BMC that have a proven track record? Even when broken, they offer the parts so you can fix it without replacing the entire hub.

 

[docnjoj]

What's wrong with a Mac/BMC that have a proven track record? Even when broken, they offer the parts so you can fix it without replacing the entire hub.

Nothing! They are fine motors. I have a Bafang ready to go if I need a backup but the gear whine really annoys me. If there is a way that the roller geared motors are as quiet as my 9C I would love to get that weight off my rear suspension. It is a bit of a risk but I think the motor alone will be about $100 plus shipping (not much because it is little). I have a good Sun rim and would just need to order spokes and lace up the wheel. Worth it for the experiment, maybe.
otherDoc

 

[amigafan2003]

What's wrong with a Mac/BMC that have a proven track record? Even when broken, they offer the parts so you can fix it without replacing the entire hub.

Well the MACs weigh 4.5kg vs 1.9kg for these small motors?

Not every application suits a big, powerful motor.

 

[d8veh]

If you want a throttle, don't use the Keyde controllers because they all require that you're pedalling before the throttle operates, and if you stop pedalling, the throttle stops.

Yeah that would be a problem. I have a sensorless controller but it seems in the Keyde ads all the motors have a built in controller. Zhang did write bck and confirm the rollers. If I can get one without the in-built controller I will order it.
otherDoc

They supply the motors with or withoout the internal controller.
http://www.keyde.com/?do=product

 

[docnjoj]

They supply the motors with or withoout the internal controller.
http://www.keyde.com/?do=product

Apparently not anymore. Zheng just wrote to me and said they must have the internal controller to be sold. I hope I am wrong but it does look like a dead end. Too bad because with the low gearing and some good quality these motors could serve a useful purpose if they had a throttle.
otherDoc

Edit: Whoops, language barrier again. Apparently you must get the rear roller motors without the internal controller as there is not enough space for it. This sounds good to me so I can use my sensorless controller I already have. I asked for price and availability.

 

[docnjoj]

Well now the "not so good news". I finally got an estimate invoice but it was for 380 USD delivered. It included a controller and apparently an internal controller/Pedalec too, neither of which I wanted. Good old language barrier again. I will try again to communicate my needs tomorrow and we will see. All I need is the motor with 3 phase wires. None of their motors seem to be sensored.
otherDoc

 

[Jeremy Harris]

Doc,

Justin has put the Tongxin motor data up on the simulator now, having tested some sample motors he's recently received. As to be expected,hey don't look to be too good at delivering a lot of power but are close to ideal for gentle assist. I've no further details on whether these are available as rear motors or whether they are only available in a front wheel version, I'm afraid. The 24V 230rpm version is the high speed one, intended for use with 16" to 20" wheels, the 36V 260rpm version is the lower speed one intended for use with 26" wheels. The samples Justin has for testing have Hall sensors.

I'm sorely tempted to get one or two when Justin has them in stock, as I really like the smooth and quiet drive from these little motors. Meanwhile I'll do some playing around with the simulator to see what sort of performance I can get.

 

[amberwolf]

Just for giggles, I did a few simulations with this motor (36V version) on CrazyBIke2 with it's present battery pack, the older 40A max ecrazyman controller, and both a 20" and a 26" wheel. I didn't notice at first but I have to pick "mountain bike" for aero setting rather than "semi recumbent", or the watts-at-speed is way off. It's pretty close with MB--must be becuse of the big boxes I have on there?

Anyway, assuming I did most of the work to get me up to 20MPH by pedalling (which I know I couldn't do), this motor could theoretically keep me there without melting. But if I tried to use it to get there without pedalling, it'd probably catch fire before I even reached that speed, depending on how I used the throttle. :lol: If I went lightly enough on it to not melt it, I'm guessing I would never actually get to 20MPH because I would reach a traffic light or a stop sign first, even on the roads with those only in 1-mile intervals.






Uisng SR instead of MB:

 

[Jeremy Harris]

Yes, these little motors certainly aren't power houses, that's for sure. They work very well for near-silent low power assist though. I had one on my SWB recumbent a while ago and it was ideal fo what I wanted. It gave a useful bit of assist when pulling away or climbing hills, without making any appreciable noise at all. It was also nice and light and had no noticeable drag when the power was off. The only downside with the Tongxin I still have was the fragile controller (now blown, as many of them do) and the fact that it was sensorless, which made for slightly jittery starts at times. I'm keen to try one of the sensored ones in my lightweight folder, as I suspect it might well be a good combination (light bike that pedals well and only gets used on relatively level ground most of the time).

 

[amberwolf]

I still have plans to use one of the older ones on my Nishiki for BB drive, if I ever get that far. I would expect it is comparable to these newer ones in terms of capability and thermal issues, when still inside it's casing (and one reason why i will probably not be using it's casing when I do this). It ought to work fine in that application (better than in a wheel, actually, AFAICT, especially if the simulation of hte newer ones represents something close to the older one).

The only thing I know I will need to do first is make a "clamping ring" to go outisde the outer ring for the rollers so it cna't split apart under the torque like that type apparently often does.

 

[Jeremy Harris]

I still have plans to use one of the older ones on my Nishiki for BB drive, if I ever get that far. I would expect it is comparable to these newer ones in terms of capability and thermal issues, when still inside it's casing (and one reason why i will probably not be using it's casing when I do this). It ought to work fine in that application (better than in a wheel, actually, AFAICT, especially if the simulation of hte newer ones represents something close to the older one).

The only thing I know I will need to do first is make a "clamping ring" to go outisde the outer ring for the rollers so it cna't split apart under the torque like that type apparently often does.

Sounds like a good plan. I believe they changed the design of these motors to stop the ring splitting, but can't be sure as I've not seen the inside of one of the newer ones, I only read a comment about it some time ago. As a BB drive I reckon it should work well, as the stories I've heard of Tongxin failures have all been when used in large diameter wheels. This suggests that they don't like delivering a lot of torque at low rpm (which makes sense given their small size) so any application that can allow them to spin faster for a given power is probably going to mean better reliability. I put a fair few miles on my original motor, and that was supposedly one of the weak ones, but that was in a 20" wheel on a fast recumbent, which bears out the theory (albeit with a very limited sample!).

 

[docnjoj]

Hmmmmm.........If I could order from Justin I might just do it. Worth the extra money for some peace of mind. I really would like to get the 9C discus off my rear suspension and also get back the freewheel. I found out how draggy those motors are even when the Phase wires are unplugged on our last episode of flat tires and dead batteries. I'll check ebikes.ca.
Thanks guys.
otherDoc