thank the inventor

Hello Joachim, I have answered your questions in my blog post: bruceteakle.blogspot.com/p/it-seems-clear-xiongda-2-speed-motor-is.html

Hello Ezequiel, many people's first question when they see my electric bikes is about regenerative braking. However there is a good reason that regenerative braking is extremely rare in ebikes: there just isn't enough energy wasted by bicycle brakes to make it worth capturing. Remember, regenerative braking is braking - it slows you down, and it needs to slow you down a lot to be generating a significant amount of energy for battery charging. Most people riding bicycles for transport do very little braking - consider how long brake pads last if you don't live on a mountain. It is only if you have long descents down hills, where you apply the brakes continuously, where a useful amount of energy would be generated, and very few people have this. People usually use normal small hills to get speed, and brake very little. Consequently the cost and complexity of regenerative braking technology in your motor and controller would not pay.

@@BruceTeakle the main plus of regenerative braking is the use of it on downhills like a retarder helping the brake pads.Not just for the charging aspect.

Daytriker, I'm very sorry I missed your question and am answering a year late. I have added grease when I have worked on these motors, to compensate for lost grease. I did try to get a supply of the grease used in the factory, but it can't be air freighted and doesn't seem to be a commercially available type. I've also tried adding automatic transmission fluid to improve lubrication and cooling of the motor, which has so far seemed to work well, but can leak.

@@BruceTeakle I've been told to use aviation grade grease that's safe for nylon. Ask the bbshd people. It's red.

Bruce, how do you untied the lid? What tools do you use for that? Thank you for the video

Oh wait, I think I might have figured it out. Is it because the section of the hub motor that is rotated on is the part of the motor that is moving? I remembered that the entire motor isn't threaded, only the part that is moving. So although the part of the hub motor which is moving is in direct contact with the shell, the stator is not, thus the power cord remains stationary . Let me know, thanks.

Hello Brooke, the power and sensor wires go thru the axle into the stator with the windings. The stator is keyed onto the shaft. The plate which holds the planet gears is also keyed onto the shaft. All the parts which rotate around the shaft are in the end plate which screws into the hub case, and of course the hub case itself rotates around the shaft. This is quite different from single speed geared hub motors, in which the plate which holds the planet gears has a freewheel which allows it to rotate around the shaft one way. I hope that helps! Bruce.

Yes, the hub can be pushed backwards. These hubs sometimes lock up and won't push backwards, then you roll them forwards a little and then they're usually fine to reverse.

Hello Jean-Valery, you understand the mechanics correctly, it is clever! I have added some photos to my blog post about this motor, which show the gears clearly enough to count. Blog post is at bruceteakle.blogspot.com/p/blog-page_20.html

i have read that it is impossible to turn the weel backwart, by hand pushing. is that a big nuisance? also its basicaly a "retro direct" drive made compact by pl. gears and el. motor

One of my Xiongda motors has a built-in temperature sensor. The temperature of the motor windings is totally dependent on the situation. On long steep climbs it can sit at 120C or a little more, on flat country it can stay under 80C. My Bafang motors have been much hotter: up to 160C. See my blog post at bruceteakle.blogspot.com/p/burning-out-bafang-hub-motors.html

I have info on opening the motor in my post on repairing: bruceteakle.blogspot.com/p/it-seems-clear-xiongda-2-speed-motor-is.html

Hello Rob, there is no cogging friction with this hub, as the freewheels are free when the motor is not powered. Same with all geared hubs (all I've ever seen), they have a freewheel which allows the wheel to spin forwards freely, but the gears and motor need to spin to push the bike backwards.

"but the gears and motor need to spin to push the bike backwards." I've heard that this causes them to break. I was wondering what your experience has been with this? I really like this motor and would like to use it to build commuter bikes and some trikes, but the breaking if let roll backwards rumor hasn't been proven false anywhere I've looked it up.

Hi Chris, I've seen reports on ES of breaking the ring gear when rolling backwards. This hasn't happened to any of our XD hubs, even with rolling bikes backward every time we take them out of the shed. I can feel them lock up sometimes, but it hasn't led to damage. We have had the nylon sun gear (for high gear) break on some motors, and replaced them with good support from XD. XD have upgraded the polymer material in the sun gears and they say they haven't had a breakage with the new material so far. Looking at reports on ES (some time ago) it seems to me that most breakage reports are the sun gear, with a couple of ring gear breaks. Does ring gear breakage look more frequent to you? As a general principle, I'm very cautious about putting high powers thru ebikes. I keep doing repairs on bikes which have been souped up to high currents and voltages, where the torque breaks things, from dropout torque plates down to the basic design elements of the motor such as axle keys. With less power, everything works better for longer - a general design principle I"m sure.

Probably the same post on es you reference is where I heard about the breakage problem. That really bummed me out to hear. I believe the subject was brought up by a guy with one on a Recumbent, and from what I remember, the consensus was that it only happens on Recumbents. I think one other guy said that it broke on a regular bike, but I'm sure that has been fixed by the factory upgrades you mention. Good to hear. I'm getting one to go on a beach cruiser for torture testing, then if all is good, I'll be getting another one for a 700c commuter bike. I probably won't use either of them with enough power to get the advertised 1000W, but a little extra would be nice for climbing hills. If I want to go fast, I'll build a bike with a Cyclone 3000w motor. I see no real need to hot rod stuff meant for slower speeds so it becomes unreliable when there are plenty of motors built for speed on the market. Like they say, just because you can do something, doesn't always mean that you should do it. Thanks for the info!!!

Found this over on the Luna website. I don't remember seeing on the motors page before. I haven't read anything about this issue over on es. Luna Cycle; "This motor requires you to downshift when going uphill, it is not automatic. If this is not done you may break the clutch."

The holes have bolts which hold on freewheel components. They are are strong - are used when opening the hub. However I don't think this would work as a mid drive. The change of gears would change your pedalling cadence. I haven't made a mid-drive bike, but my understanding is that it would be easiest with a direct drive motor which would be able to drive backwards, e.g. Conhis Motor.

ty for the reply , nice to know they are strong :) pedal cadence is not a issue for me as it would drive the rear wheel directly on the left side passing through 3speed hub jackshaft .. the crank will drives a coaster brake like a normal bike .. thanks again for sharing this video

Sounds interesting: please show us what you make!

i recently joined ES ,ill start a build tread once i have my e-parts , will likely include a title like '1914 Cyclone'

Hello Ben, I explain how to open the 2-speed XD motors in my blog post: bruceteakle.blogspot.com/p/it-seems-clear-xiongda-2-speed-motor-is.html I haven't tried opening single speed XD motors so far, but I hope this helps.

@@BruceTeakle ah thanks so much for the link. I already had worked out i was going for the wrong side of the motor. I just put in 2 longer bolts and turned out the the plate that holds the clutch. everything about my motor seams to be fine including the clutch and yet when I push the bike backwards it spins up the stator where it didn't before. my controller burned out when this started so I assumed the motor was dead. coils are all good and clutch turns one direction and not the other..

Hello Akshay, I didn't count the teeth on the primary sun gear, so I'm not sure of the overall reduction. I'll count it next time I have a motor open. the difference between the 2 gears is 54/30 - less than 2:1. For a link to the Xiongda website, see my blog post, linked above in the description.

Hello Josep, I don't know about Samsung equipment, I have only used Chinese motors: Bafang/8Fun and Xiongda. Bafang and Xiongda both make rear hub motors that draw 15A, but both use 7-speed spin-on clusters. Bafang make a higher powered motor called a CST which takes an 8 speed cassette, like this: www.greenbikekit.com/electric-motor/rear-bldc/bafang-cst-bldc-motor.html There is also a generic motor available that takes an 8 speed cassette: www.greenbikekit.com/electric-motor/rear-bldc/e-bike-cassette-freewheel-hub-motor-36v-250w-light-weight-high-speed.html I haven't tried it but I expect it is fine. I have used the Bafang rear hubs, both 15A SWXH and 18A BPM and they are both good motors. They use a 7-speed spin-on cluster so you usually use 2 front sprockets with front derailleur.

Bruce Teakle No se inglés o siento, no me entero de nada

Bruce Teakle Google translate: Hola Josep, no sé de los equipos de Samsung, solo he usado motores chinos: Bafang / 8Fun y Xiongda. Tanto Bafang como Xiongda fabrican motores de cubo trasero que dibujan 15A, pero ambos usan grupos de rotación de 7 velocidades. Bafang fabrica un motor de mayor potencia llamado CST que lleva un cassette de 8 velocidades, como este: www.greenbikekit.com/electric-motor/rear-bldc/bafang-cst-bldc-motor.html. También hay un motor genérico disponible que lleva un cassette de 8 velocidades: www.greenbikekit.com/electric-motor/rear-bldc/e-bike-cassette-freewheel-hub-motor-36v-250w-light-weight-high-speed.html No lo he intentado, pero espero que esté bien He usado los bujes traseros Bafang, tanto 15A SWXH como 18A BPM, y ambos son buenos motores. Usan un clúster giratorio de 7 velocidades, por lo que generalmente usa 2 piñones delanteros con desviador delantero.

Have a look at my blog post here for info on opening the motor: bruceteakle.blogspot.com/p/it-seems-clear-xiongda-2-speed-motor-is.html

Thank you so much

Justin Lemire-Elmore of Grin Tech made a geared hub with regen. It's essentially an Ezee/BMC/MAC-style motor, but with a locked clutch. That would not be possible with this Xiongda tho, at least not without losing the double-speed action!

Hi Leps, every hub motor I know uses plastic gears. I think it's fundamental to manufacturing machines that are durable enough at low cost. Generally they use alternating steel to nylon. I've only ever had to replace nylon gears on one Bafang motor (see my post at bruceteakle.blogspot.com/p/electric.html), and a few times on these Xiongda 2-speed motors due to some early engineering problems - see my post at bruceteakle.blogspot.com/p/it-seems-clear-xiongda-2-speed-motor-is.html. We have 10s of 1000s of km ridden on Bafang and Xiongda motors in our family. The Bafang mid-drive BBS motor units also use nylon gears, which also occasionally need replacing (but we haven't had to yet in our family). Replacing some cheap nylon gears after many 1000s of km isn't a big problem - cheap and easy. You'll have many times more trouble with suspension forks or derailleur gears. Some people do replace plastic gears with steel so that they can run much more power thru their motors than they are designed for. I expect that as well as being much more noisy, this results in wear of the steel gears, which would create more problems than occasional plastic gear replacement (if they don't cook the motor windings first with high currents). I believe the European and Japanese mid-drive motors use only highly engineered steel gears. But these are very complex, very expensive to buy and very expensive to repair.

@@BruceTeakle well I could not expect a better answer. Thanks, I'll treasure what you said and your experience (which values a lot). I certainly feel more comfortable in buying an ebike now! Thanks again!!

www.xiongdamotor.com.cn/

difflocktwo This motor is a Xiongda 250w motor for a 20" wheel, peak powered speed about 30km/h at nominal 36v, with KT 7A/15A controller. Peak speed on low gear is around 16km/h. For my review of the Xiongda 2-speed motor, see bruceteakle.blogspot.com.au/p/blog-page_20.html

Bruce Teakle Interesting budget motor, other than some reports of the free wheels locking up when rolling backwards. Guess its closer to 40kph with a 26" wheel.

difflocktwo Sometimes the freewheel does jam when rolling backwards, but we have found that you only need to roll forward a few inches and it comes free. The motors made for 26" are wound for a slower rpm. They actually seem to be slightly slower than the 20" motor (which is probably good overall). I think they're a really good motor if you have long steep hills to climb.

That's right, this motor can't do regenerative braking due to its freewheels. As I explain in my reply below to Ezequiel, there isn't actually enough braking energy wasted in most cycling to make regeneration braking worthwhile. Regenerative braking is braking, that slows you down, and we don't usually spend much time doing that.

I rode an electric bike for the first time last night with a friend who I helped get his new speed controller working on his bike. It turned out that the hall sensor in his throttle was broken. Anyway, what I found was that it's really easy to keep the bike going fast by pedaling, but it's difficult to get the bike up to speed, so the power from the electric motor mainly helps for acceleration. I don't really feel the need to sit there without pedaling at all when it's so easy to pedal. However, I did have to slow down a lot quite often because it was so easy to get going pretty fast after every stop. Therefor, I'm not so sure that there isn't very much opportunity to recover energy from regenerative braking. I felt guilty that I was wasting energy (and range) every time I hit the brakes. Also, my friend said that even though he has disk brakes on his bikes, they are insufficient due to the added weight of the hub motors and batteries. Regenerative braking should actually slow down the bike quite sufficiently adding to the performance of the undersized brakes. So, I don't know. Maybe the regenerative braking features in these speed controllers aren't implemented very well. Or maybe it's not possible to implement them very well. I haven't tried it yet to see what I think of it.

@@BruceTeakle Bruce you're right, however regenerative braking is used mostly to reduce a huge wear in braking system (disk and braking pads). Using regenerative braking can prolong your brakes by 90%. I'm almost not touching brakes during long downhill trips. Thanks for the video!:)

@@The_Unobtainium I agree, where I live region braking would save me a lot of brake parts (pads, discs) and maintenance, if not much energy. What sort of motor are you using?

@@The_Unobtainium Hello Ilive, thanks for your feedback. What sort of motor are you using?

Hi David, when the controller senses the speed has risen (or fallen) to about 15km/h, it automatically stops power to the motor, and re-starts in reverse direction, thus changing the gear. This feels a little strange at first.

@@BruceTeakle Thanks for your reply it does make sense. Do you know is it possible to work with a torque sensor (e.g. from pedal) instead of a speed sensor to change the gears? Also, is the speed sensor inside the motor or on the rim of the wheel?

@@BruceTeakle Sorry i got too many questions I hope it won't annoy you. Apart from sensors, do you think I can manually control the speed with a switch maybe from the handle?

@@davidkk1166 Hi David, I think you're asking if you could change the gears with a different control from the automatic, speed-based shift it comes with? If so: yes. There is manual control with the KT controllers Xiongda usually use. The "HAL" switch allows you to choose High, Automatic or Low with a switch on the handlebar (see my blog post). Re using a torque sensor: this would require more electronic genius than you can find in my workshop. It would also run into the limitations of electric motors. There is a torque/speed curve that means you don't want to go much less than 15km/h in high gear or you'll overheat, and you can't go much more than 15km/h in low gear as the motor spins out (has no torque). I usually leave my bikes on automatic, but sometimes use the HAL switch to force the motor to stay in low gear when I have short, flatter sections of climbs where I want the motor to cool off a bit by staying at high revs.

@@BruceTeakle Hi Bruce, a manual control is actually what I am looking for but it is nice that it can work in both manual and auto control. I have looked up on your blog and it is really detailed. However, is the switch from the same company as well? I have also looked up on the Xiongda on Alibaba (couldn't find their own website) and seems they don't have the switch or no longer available.

I believe Bruce is saying each individual set of planetary gears has its own one-way engagement device so if the motor is instructed to run backwards...a different forward ratio emerges. I think. Just guessing... And why are you yelling? Perhaps you consider purchasing one of these hubs and producing the video you obviously think this should have been. Yikes...another comment below. I hope everything is OK.

if i'm not mistaken, it goes as followed: in speed 1 (engine going forward ) the primary sun drives the primary planet which drives the secondary planet, which drives the 2nd sun, which drives the wheel (the ring gear is then in freewheel mode) in speed 2 (engine going backward) the primary sun drives the primary planet which drives the secondary planet, which drives the ring gear, which drives the wheel (the secondary sun is then in freewheel mode)