Charcoal bags

Charcoal bags

Search This Blog

Xiongda 2-speed hub motor Review – First impressions


I wrote the page below a few years ago, when I first installed a Xiongda 2-speed motor in my folding bike. Since then, we have installed a few more and done well over 10,000 km on these motors (mostly 2 motors), and I really like them. We've had a few breakdowns and repairs, the important ones are described in my posts about the sun gear failing, and the motor magnets coming unglued. All the motors we have installed are still running well. Importantly, we haven't had any burnt motor windings - so the XD motors have solved the problem we hoped to solve (and we have a box of Bafang motors we have burnt on our long, slow climbs). 

The Xiongda 2-speed motor

The Xiongda double-speed motor is a brilliant innovation in ebike hub motors. It could be the solution to my mountain-climbing, motor-overheating problems. It looks like a useful option for people riding low (or legal) powered ebikes in steep country or who otherwise need more torque.
I recently took delivery of some hub motors from Xiongda Motors ( I’ve installed one of their 2-speed hub motors on the front of my main folding bike (a Dahon Boardwalk, described more in my post here), and have had a few weeks and a few hundred km to get some first impressions. So far I’m very pleased with it.

What is a double-speed motor?

These motors are geared hub motors like most small ebike motors, where the motor spins faster than the wheel and is geared down with a planetary gear drive. The difference is these have a second internal planetary gear which can deliver two different speeds.
The 2-speed hub changes gears simply by reversing the direction of the motor inside the hub. Internal freewheels deliver different speeds from the planetary gears according to the direction of rotation – but still drive the wheel forwards.
Here's a video showing how it works inside:

How this works is explained very well in this post:
These endless sphere forum pages have a lot of discussion and some good photos of the motors’ internals: 

Installing the 2-speed Xiongda

Xiongda Motors was very good to deal with by email, and the motors and associated equipment arrived with the best packing I’ve ever seen when buying Chinese ebike parts.
For my Dahon, I ordered a front motor, wound for the folding bike’s 20” wheel size. This is a 250w unit, intended to be (approximately) road legal.
All the Xiongda motors were supplied with waterproof plugs in the motor power cable, at a position chosen by the customer, enabling easy disconnection for repairs (e.g. flat tyre). Power cables exit the motor through the axle.
The front forks needed a little bending to fit the front motor, as these motors are slightly wider than standard 100mm. Additionally, these motors have a boxy shape to fit the extra internal gears, making them even harder to fit in some forks, especially suspension forks (especially forks not made to fit disc brakes).
Because of this width, the front 2-speed motors are not able to take brake discs.
Xiongda provide enough handlebar switches and displays to nearly fill up your handlebars.
An LCD display (in middle of handlebars) attaches to the controller with a plug. The LCD is permanently attached (on a cable) to a power, up and down switch (in photo above on left side, below brake lever). This switches the controller on with the middle button, changes pedal assistance sensor (PAS) power level (I don’t have a PAS on this bike). Switch combinations change the LCD display items. The LCD is able to set a maximum powered speed, but I suspect this is when using PAS (I need to get a PAS and find out).
If you don’t buy an LCD, you need a “short circuit plug” to enable the controller to turn on, seen attached to the left hand controller in the photo below (at top, with red and black wire loops).  
The controller for the 2-speed motor is the right-hand unit in the above photo, the left-hand controller is for a single-speed motor, and has different plugs.
Note also on the handlebars there is a switch marked HAL: High, Automatic, Low. This connects separately to the controller, and selects the gear in the 2-speed hub.
After 11,000 km of using a previous front hub motor, I noticed some flaring of the fork dropouts on this bike. Considering the additional torque the 2-speed motor would impose on the dropouts, I installed a torque lever (from, to manage torque forces.

Riding with the 2-speed motor

After you plug in your charged battery, you need to turn on the controller with a long push on the power button. Once on, you can change the display to show a few options, including battery voltage, odometer and trip distance (if you reset after trips – the LCD instructions tell you how).
I haven’t installed a PAS, so I can only power with the throttle (after re-reading the forum discussion at endless sphere, I wonder if this is the cause of my relatively high power consumption with this motor). With a PAS, you can select different assistance levels with the up-down buttons.
Using the HAL button, you can choose high or low gear manually, or let the controller decide by selecting A for Automatic. I find automatic works well most of the time, but sometimes I manually choose a gear, e.g. when I’m doing a long climb and I don’t want it to keep changing gear during flatter sections.
In high gear, this motor provides useful power (that you can feel) to about 29km/h at full throttle. In low gear, the motor spins out at about 16km/h.
In Automatic mode, the motor will usually start in low gear. Once you get up to 16km/h for a few seconds, it changes to high gear automatically. When it changes gear, the bike loses power for about 1 second, then starts again in high gear. This also happens when slowing down for a hill: when you’ve slowed to about 15km/h for a few seconds, the motor power drops out for a second and then restarts in low gear.

My feedback

The quality of the motor and other parts provided by Xiongda is good, as is their service.
The 2-speed motor solves a significant problem for some ebikers: the overheating of motors when running at low speed and full throttle for significant periods. As I’ve written elsewhere, for normal 250w, 25km/h hub motors (approximately road legal in Australia or Europe), working at full throttle, slower than 15km/h, for more than about one minute, generates potentially damaging temperatures in the motor windings. At these speeds most of the electrical energy consumed by the motor becomes heat, instead of power.
The 2-speed motor changes gears when the motor starts working in this overheating zone, and consequently avoids overheating, reduces energy consumption, and maintains a better speed. From my calculations it appears that at 13 - 14km/h, which the motor tends to maintain in low gear on steep climbs (around 15% slopes), the motor is close to peak efficiency.
The KT controller does seem to get very hot during long climbs, getting too hot to keep a hand on, in a partly-ventilated aluminium box (with some heat-sinking from the box). Its label gives it a 7A continuous rating, 15A peak, but it appears to deliver about 15A continuously during climbs. I suspect overheating due to the high current is the cause of some dropping out of power during long climbs, especially during gear changes. Bonnie at Xiongda suggests getting a Nanjing Lishui controller as a higher quality option – I’ll try soon [this is no longer available].

Who would the 2-speed motor be useful for?

Most ebike users ride in flat cities, carrying small loads. For this purpose, the common single-speed hub motor is excellent. Steep hills are usually short, and the simplicity and reliability of the single-speed motor makes it the best option.
The most obvious beneficiaries of the 2-speed motor are people like me who live in mountainous areas with long, steep climbs. For us, the double speed motor reduces overheating, and is faster, lighter and more efficient than heavy motors such as the Bafang BPM, which also deals well with hills.
I expect the 2-speed motor would also help people who can’t provide enough pedal power to deal with their hills. Someone old and light might be able to travel on hilly roads without needing to really pedal at all. It would be good in any situation where a single-speed motor would spend long periods labouring at a low speed and risking overheating.

2000km update

After 2000km I'm still using the Xiongda on my Dahon. It's still going well.

I've installed the PAS (pedal assistance sensor) so I can motor without the throttle. This is significantly different from using a throttle, mostly because you can select different assistance levels which in some situations can help to meter out the battery energy to last for a long trip.

10,000km update (September 2016)

We now have about 10,000km of total travel clocked on 2 Xiongda 2-speed motors: this motor on my Dahon and a 26" rear motor on my son's mountain bike. My confidence is increasing - enough to buy 3 more 2-speed motors. 
These motors do seem to be the best solution to our hill climbing, motor overheating problems. Over and over again, they haul us and our luggage up steep hills, especially the 3km of continuous ~15% climb up our mountain, without trouble. 
They can be noisy - this seems to be in the freewheel unit. I haven't yet explored where this noise has been coming from, I need to take some time to pull one apart. Changing freewheel units has eliminated the noise on one motor. 
We have had 2 breakdowns, each time the same part failing: the nylon sun gear. See my post on this at
Interestingly the gear that fails is the high speed gear, not the gear that does the heavy climbing (which is the nylon internal ring gear). Xiongda is working on this problem, apparently with a stronger plastic gear material. 
For us this is an acceptable weakness, given how much of a problem overheating has been with single speed hub motors, and I expect Xiongda to find solutions. 
Currently I tend to set my power level at 4 (on the KT LCD) for pedelec power, and use the throttle (or switch to power level 5) to give me full power for steep climbs. I expect this will reduce wear and increase life for the nylon sun gear, as well as increasing my range.

Update September 2018

We now have 4 Xiongda 2-speeds on our bikes, all working well. 
I've added automatic transmission fluid (ATF) to 2 motors, including in the Dahon described above, to help lubricate and cool the gears, freewheels and motor. The ATF can leak out in some circumstances, but rarely much. I think it does help with cooling, and it makes them quieter. 
One motor needed repair due to the motor magnets coming unglued. This is described in my blog post here
The motors are going very well, and I remain very happy with them. The Dahon has done 7715km, which is 325 riding hours - cumulatively equivalent to 2 weeks riding 24 hours per day! I am riding less currently as our school and family travel patterns have changed, and I'm spending more time at home (we still only have one car). 

Extra info on Xiongda

As well as the 20” front 2-speed motor, I bought a 26” rear 2-speed motor and a 26” front single-speed motor from Xiongda. I haven’t put these into bikes yet, but I am impressed with them at this stage.
Here is the 26” rear 2-speed motor:
Xiongda 2-speed rear hub motor
Xiongda 2-speed rear hub motor

Note that the threaded boss for the spin-on cluster is steel, and not part of the aluminium casting. This avoids a common cause of rear motor failure, where the threaded boss can break off the motor side plate.
The rear 2-speed motor is disc brake capable (there isn’t room between the forks to fit a disc on a front 2-speed motor).
Here is the 26” front single-speed motor:
Xiongda single-speed front motor (similar to Bafang SWXK)

Xiongda single-speed front motor - note cable exit from shaft
It is disc brake capable, and has an unusual (to me) exit of the power cable through a hole in the axle inboard of the dropout. The side plate looks very similar to that on a Bafang SWXK but cannot be removed with an SWXK side plate tool.

Motor drawings 

These drawings are from late 2014 and were accurate at the time. I'm not sure if changes to specifications have occurred since. The motor opens by unscrewing the side plate (clutch plate) on the right hand side, which has a right hand thread. 

Extra Photos

Clearance with Dahon fork at dropout
The first set of planetary gears: the magnet drum drives a small gear in the middle of these nylon planet gears. The planet gears have a shaft which connects to the steel planet gears in the second planetary gears, pictured below. 
The steel planet gears at top drive the nylon ring and sun gears below whenever the motor is running. The ring and sun gears each have freewheels, one of which engages when the steel planets turn one way, and the other which engages when the planets turn the other way. 


  1. Have you tried the nanjing lishui controller yet? Is that the controller as shown on their website kit, do you know? If not, do you know where to get one, and would you need a different controller? Thanks.

  2. I just got mine, with Lishui, installed 2 weeks ago. They give you a choice. Love it. I can feel the controller going down the road, and it gets a LITTLE warm after lots of full throttle. And my 16" application is on the front wheel of a recumbent tandem, so it's dragging ~200 kg up and down hills. Simpler than the other brand too....

    1. Hi Bob,
      how is your experience by now? I want to install a 2-speed in the 20"front of my Douze Cargo bike (simillar to a bullit). On the bike is a huge Toolbox, so the whole system weight is arround 150kg (me 75kg, the bike 25kg, the tool box loaded 50kg). And the bike needs to carry me arround reliable for about 40km daily in Berlin (not very hilly, but need to get up sometimes steep ramps). I don't like to peddle much, since I am usually exhausted from work (I am industral climber, very physical work), so would love the motor to drag me most of the time. Am considering either a dd drive, but fear it has not much torque in low speed or this 2-Speed, but fear it is not reliable enough (its for work)? What would be your suggestion?
      Any advice from someone else?

    2. Hello Florian,
      This is a good question!
      The Xiongda would probably be good. It would give you a higher speed to travel around on the flat, and would have plenty of torque to haul up ramps and hills. However you are right that it has some reliability challenges. See my page on repairing the Xiongda 2 speed at:
      As the page outlines, it appears to me that the usual weakness is the nylon planet gear, which is relatively easily replaced, but there is still the cost of breakdown time. Xiongda is switching to a stronger material for this gear, which may reduce the risk. I've done about 4000km on my current (not new material) nylon planet gear so they aren't terrible.
      Another option I would suggest is a Bafang BPM code 10 front motor (the higher speed version). See my page on the Bafang BPM at:
      I think bmsbattery is offering this at this page:
      It's unclear what code the motors are on this web shop - be cautious about the specified rpm.
      The BPM is a very strong and reliable motor. I haven't laced one into a 20" rim but I'm not sure how it would go with 1-cross. Perhaps it would need radial spoking due to the shortness of the spokes. The other limitation of the BPM is that it would be relatively slow. My expectation is that a code 10 motor in a 20" rim would have a top powered speed of about 22km/h.
      Good luck, I'd like to hear how you go. Bruce.

    3. Hi Bruce,
      sorry for the long delay. Have bought meanwhile a complete motor already spoked into a wheel, controler, display, 650wh battery for cheap 480 Euros from Leon Cycles, cause I know someone there. It works cause Berlin is flat.
      But now I consider to ad a biketrailer for the extra material load on bigger construction sides. I assume the single speed from leon will not give enough push with this load.
      Unfortuanately I have disc breaks.
      Bonny from xiongda said its possible if the fork dropout is 110..? My 100mm fork is steal, can I widen it that much?
      What do you think?

    4. I think you should be able to make this work fine. Widening steel forks (with no suspension) hasn't been a problem for us so far. They can be bent cold. I put the steerer tube into a vice and bend the forks one at a time. Bending the first fork should give you half the increase you are wanting.
      If you are using disc brakes, you may have some complications due to slightly changing the angle of the disc brake mount. However this is likely to be able to fix either with adjusting the caliper mounting bolts in their slots, or perhaps using a thin washer between the frame lugs and the caliper bridge, or even filing the bridge a little.
      I haven't used a disc on a XD front motor yet, only rear motors. On rear motors it is best to use a disc of at least 180mm to give clearance between disc and motor hub for the caliper, and I suspect the front motor will have the same situation.
      Perhaps send a photo of your forks?

    5. Hi bruce, i'm from munich, so lots of good hills nearby. I drive since 4years 50tsd altitude meters with xd ds rear 250w 36v and hailong 10s5p with samsung 35-E, 630wh. All works perfect. Had just now changed spares from bonnie (outer ringgear and nylon sungear) all other ok. About your partly overheatung... i realized that even on a new motor some small works has to be done to reduce noise nearly to zero... the small hubbles on the outside of outer great ringgear should be very carefully grinded to avoid the rubbing of the nylon to the aluminium housing, the space is very narrow. 2. The 3 metal plates that are fixed with 6 4mm screws makes a little resistance at the split where it fixes the rotating outer ringgear on the clutch plate. I removed that 3 plates and did a very little grinding and smoothing on the edge that come into the split of the ringgear.
      In my experience these two rubbings leads in best case only to little noise, little heating and little power loss. In worst case the heating due to rubbing leads that the fixing of the outer big nylon ringgear will become loose from the rotating freewheel. On my controller i made a very litte ventilator (two 10mm holes carefully drilled and ventilate directly to the electronic. Works good and enough.
      For me no alternative to xd ds. Even most of the mid motors have no chance at more than 15%
      Best regards. Siggi steinkirch er

    6. Hello Siggi, thanks for sharing your experience and advice. I have often wondered why the XD is so noisy - I shall follow your lead and see if I can improve things next time I have a motor open.

    7. Hi bruce, thats done in a few minutes, noisy now only at low gear at 5. You will see, ringgear runs at open motor without resistance.

  3. Is the display detachable??

    Will all motor functions work without the display on the bike??

    Is the display optional??

    Thank You.........Thomas

  4. The display is optional, I did order one motor without display. The motor can be installed without the display, using a short circuit plug instead (this is my understanding - I haven't tried it yet). The only thing the display enables in motor function is PAS power control - which is actually quite useful if you want to reduce power consumption and increase range. Once installed with the display, it is detachable but not easily: unmount it from the handlebars by unscrewing the mounts, unplug it from the controller, plug in short-circuit plug in its place.

  5. Bruce, Thanks, finally some practical info on Bafang motors and the new XD double speed motor. I have a CNE Bikes 200w 36v front hub 26" wheel kit now 2 years old and it never had much power. We previously had folding 200W E-Bikes from E Value-E-Bikes which had lots more "grunt". Now it continually blows the 20 amp fuse that is inside the new 36v 11Ah bottle lithium battery. I got GreenSpokes to check it and at 50% load it consumes 257 watts. Stall torque used 14.5 amp consuming almost 600 watts. As it is blowing a 20 amp fuse it must be consuming about 600 watts so naturally I cannot ride the bike for the expected 1.7 hours duration, it only does about .7 of an hour and the effective power is considerably less than 200 watts. It has a LED 880 model control and the low and medium settings are virtually useless. CNE website states "Brushless DC motor controller. Intelligent controller, engineered to be safe, prevent overheating and avoid motor or battery damage." Clearly my controller may not be working properly and the motor is very inefficient. CNE have not answered any requests for clarification. I was considering a Bafang replacement until reading your Bafang problems and SD D/S motor praise. I have asked for prices from Bonnie at Xiongdamotor and if an SD kit with 26" wheel will be produced. If not maybe a local bike shop can change-over my existing wheel. I live up a hill so the SD looks attractive. Swoosh ! Steve Garie

  6. Bruce, Bonnie replied with US$ : SD D/S motor 130, controller 31 (unsure which one), LCD display 28, PAS 3, throttle 7, lacing 26" wheel 35 (assume they supply it), delivery 140, total US$373 so about AU$570 but a Bafang 250W 36V front hub 26" from Value-E-Bikes is AU$285 and add delivery maybe $60 ? So I need to consider spending the extra $200 for the extra climbing power and assumed longer life. Bonnie thinks a rear SD D/S motor would be better which conflicts with your practical usage and front/rear/centre motors do not seem to have any particular advantages except the front is easier to fit. Cheers, Steve.

    1. Hi Steve, you have some trouble! Please clarify:
      - your fuse is blowing frequently now. Did it not blow at first, but started blowing at some point?
      - what sort of work is your bike doing? Heavy loads? Steep hills? Low speeds?
      - what sort of gearing does your bike have? Derailleur? How many sprockets in the rear?
      Shipping whole wheels is expensive. That is why I had to learn wheel building.
      Rear hub motors do have better traction. On steep dirt roads, or steep wet roads, front motors can skid which is a real nuisance, especially for light riders. With 2-speed motors this problem is worse, as there is more torque.
      I like hub gears, which means using front hub motors. However if you're using derailleur gears, there is not much disadvantage to a rear motor. It is harder to install a rear motor, and the XD 2-speed motors require the frame to be bent outwards a little to fit the wider motor in.
      Looking at the CNE bikes website, their front kit appears to use a Bafang motor. Do you know?

  7. Hi Bruce, Fuses started blowing so I got it checked and since then too often. The maximum size 20x5mm fuse I can get is 20A from Aztronics. No fun going out and stopping to change, the same reason I use Schwalbe Marathon 26x1.5 tyres. I am 80Kg and cycle real easy using thumb throttle but pedelec most of the time and the fuse blows when I least expect it, usually under no great load or where the motor would be hot. My old Diamond Back bike gears are Shimano Exage now with 2 front & 7 rear sprockets. I am happy using a front hub motor on sealed roads & Linear Park paths with some steeper inclines and more pedalling effort which is OK but the XD motor looks brilliant. CNE motors are not labelled and there are no specs. There was a rumour of Bafang copies so I was surprised that you had problems with genuine ones. I think my inefficient motor combined with a now faulty controller is the problem so would like to buy an XD with the associated bits to rule out existing problems. Please advise the shipping cost for a motor as the website does not provide this option. It can come by sea if cheaper as there is no rush to ride with Winter here. I will see my bike shop re cost to rebuild my CNE wheel which is a Samson High Power double wall alloy rim with 36 spokes as I do not anticipate needing to buy the various tools. My Diamond Back has a steel frame so would I need to fit torque levers ?
    Cheers, Steve*

  8. Bruce, A few queries before I email Bonnie again for specific parts prices and then an order. Her previous kit delivery without a wheel was US$75, still expensive. Bonnie suggested a Nanjing Lishui controller for XD motor but it is not mentioned anywhere or the required model so the reversing function electrics must be in the motor ? Can Bonnie supply a Nanjing controller and torque levers ?
    Maximum diameter stated 132mm but what diameter is that ?
    How much bigger than 100mm is the front fork distance as you bent yours to fit, mine being steel may give a bit ? It looks like a H-A-L switch is supplied but I can probably use my LED 880 display,PAS & thumb throttle.
    My bike shop will charge about $40 to rebuild my wheel, may reuse spokes if able. Please clarify any points. Steve

    1. Hello Steve, Bonnie is very helpful and provides really good service - hard to find in the DIY ebike scene. I haven't used a Lishui controller yet, I have one ready to go tho. I have so far used the other option for XD 2spd which is KT. I understand the Lishui are probably better quality. You need to use the controller from XD as the speed changes happen in the controller. I recommend getting a display, PAS and throttle from Bonnie as they have a smaller size of plug than what has been normal on parts I have previously bought.
      The motor overall diameter is 132mm. The flange spoke hole circle diameter is 121mm, the same as the 250w Bafangs, so you have a good chance of re-using the spokes if you stick with the front wheel and your current motor is a Bafang copy. Re-using spokes is a good plan.
      The over locknut dimension of the front XD 2spd motors is 110mm. If your spokes are steel this shouldn't be a problem. You will probably need to bend the forks before installation. I suggest taking the forks off the bike and putting the steerer tube into a vice. Bend one fork blade out to make 105mm between dropouts, then bend the other blade to make 110mm. My experience is that normal steel forks bend fine cold - but I haven't tried many forks.
      A torque lever is a good idea, otherwise your dropouts may bend out over time. I've used the ones sold by Green Bike Kit, but I'm not that happy with the 2-piece design and I'm more inclined to make a custom unit.
      My Bafangs burnt out because of what I did to them. Long slow climbs at 10-12km/h isn't okay for them. I have had some fail without long-term abuse too - clearly there is a lot of inconsistent quality control in ebike manufacturing.
      Does this cover everything?
      Best wishes from Bruce.

  9. Bruce, All good. I will email Bonnie, get all the items, see my bike shop for fitting and probably bending the forks as I have no vice and then post the results here. Thanks for all your help and practical experience. Steve

    1. Hi Steve,I've been wanting to build a bike using the rear wheel XD version for quite some time and have been looking at wheel building videos by Bruce and others, but at $40 I'd rather a professional do it.So I'll be keen on hearing about you're build. Could you please provide the name of who will be building your wheel as I am from Adelaide, and wondered if you are also from Adelaide?

    2. Bruce & Rob, Bonnie is very helpful & will advise me early next week if cheaper, slower delivery can be arranged. The XD display is a Bigstone C600 at The Lishui XD controller comes with a variation on the HAL switch. They can provide motor installation widths from 100mm to 145mm so assume this is similar for rear motors.
      I use International Cycles at 70 Payneham Rd, Stepney, 83622609 and the price is about $40 if no problems and we may be able to reuse the spokes. A wheel supplied by Bonnie is US$35 (AU47) but local also saves on freight. I do not think a normal wheel is strong enough and I am reusing my CNE wheel with the inefficient motor. If you are definitely interested in a XD motor we could share the freight but I am placing my order after Bonnie advises the freight. Email me at if interested. Cheers, Steve.
      See my E-Bike at

  10. Well done, sir...and thank you for linking to our article (

  11. Could you tell me the spoke length and rims used on your 20" wheel please? - I am thinking of a Raleigh Twenty rebuild with a simple rear wheel Hub of this type (no gears just freewheel).
    I built one using a marin Kentfield (Front Wheel Kit) and it was fun but I am thinking a much simpler machine now.

    1. Hello Ian, I used a 36hole 20" rim and 140mm 13gauge spokes from, with 1 cross. Have a look at my page on wheel building for ebikes at:

  12. I like you enjoy reading their comments and sometimes get ideas from them.
    12v dc gear motor

  13. After looking for electric 1, I bought petrol motorbike, now I was thinking it would be good to also have electric power on it. As I would want 2 speed, slow that would get up any hill, & fast about 40-50 mph, I found this site.

  14. Bruce, you seem to have good knowledge on this motor so I have a few questions, hope you can help me. I have a 8fun BPM motor on a single bike that I tried on our tandem, it worked fine, but this 2 speed motor may be better. I realize I have to spread the dropouts,but am concerned that it won't clear the fork blades. The BPM motor just cleared the blades by the disk bolts by a few mm's. The dropouts are welded at the center of the fork blades at the bottom, not to one side ,so there is more blade on the inside to interfere with the motor. I haven't found any dimensions for the 2 speed motor, do you know of a site that has that information?
    Do you think this would be a better motor than the 8 fun for a tandem? Luna Cycle has a kit with a 48 volt battery that I am thinking of getting. Thanks, Paul

    1. Hello Paul, I think your concerns are valid. The XD 2speed is a wide and square hub which will fill up fork space. Despite this I managed to fit it (just) in my Dahon front forks, which also have centred dropouts.
      I've added 2 drawings to the bottom of the blog page above which might help.
      Would the XD be better for a tandem? Hard to say. The BPM is a modest, simple and reliable motor which I am very fond of for cargo bikes. In its sweet zone it is higher powered and faster than the XD. However it requires a trade off between speed and torque. E.g. a code 12 36V BPM would haul a tandem up 10 - 12% hills really well, but not power you faster than about 24km/h on the flat (see my cargo bike page
      The XD 2sp will give higher top speed, good climbing and higher efficiency than a BPM, at the cost of complexity and perhaps less reliability.

  15. Bruce, thanks for your prompt reply. Your Dahon fork seems to be similar to what I am using on the tandem. Can you tell me how much clearance there is between the fork and motor 60 mm up from the axle centerline. At that dimension my fork measures 23 mm diameter. I just don't want to order and receive it and not be able to use it.
    Like I said, the BPM motor moved us along just fine,we do pedal up the hills in low gear,and we really want the e assist for the wind at your back feeling,you know what I mean. I am leaning toward going with another BPM for the tandem Would like to have a bit more range though, the kit I would be buying comes with a 36v 11ah battery. The 2 speed motor would have a 48v 13.5 ah battery. Decisions. Thanks,Paul

  16. Bruce, wondering if you saw my last post about decisions? Paul

    1. Hi Paul, I had a chance to measure and photo my front hub, photos at the bottom of the page above. The gap measures about 4mm minimum.
      Re range, I often travel with 2 batteries, e.g. on the round trip to our nearest train station which is 29km and 650m altitude away from home. I would consider keeping the same voltage as any other bikes you have to make this possible. It may be necessary to insert plugs (I use Anderson 15/45A plugs) to join in other batteries. I also use an extension cable made with Andersons to join to a second battery in a pannier.

  17. Hi! I am interested in modifying a foldable bike, quite similar to your dahon, with a rear hub motor. I use it for commuting 200-250 days per year, no more than 6-7 miles per day. I am very happy with it, but I want to upgrade it a little. I want to remove the 7speed sram hub (about 4 pounds the hub only) and add the motor, in order to keep the bike as lightweight as possible. I intend to use it with a hoverboard 10s2p battery, 6.8 Ah, as a short autonomy of the battery does not bother me. The bike currently weighs about 30 pounds and i don't want it to weigh more than 40 pounds in the electric configuration, with the wires and everything. I want to use it to make my life easier especially on windy days. Also, I will have to take it up on my back to 3rd floor. Sadly, there is no elevator. Let's say once a week, I will have to climb some short but steep roads in my city, no longer than 1/3 mile and this dual gear hub motor seems interesting and I find your information very useful. However I have a few questions.
    - Do they fit the motor to a double wall 20inch rim? If not, I will have to purchase some 12 or 13g spokes, but I don't know the length of the spokes. I see you fitted it in the same type of rim on your Dahon.
    - I will use it in Europe, but police are ignorant in my country about regulations. Does the controller assist me while pedalling beyond 15 mph or does it just cut the power? Shoukd I use a Canadian approved controller instead? How many ampsmshould I order?
    - The are some steel gears for bafang and other motors to replace the nylon ones. Are there similar gears for xiongda? The noise does not bother me. If not, do they sell spare parts or I will just need to buy a new motor just for these parts?
    Thank you very much

  18. Hello Nedormitul,
    Firstly, it is worth considering whether the Xiongda (XD) 2speed is the best hub for you. It is a marvellous machine for long steep climbs, like I have every trip. However a single speed motor, like a Bafang/8fun SWXH is simpler, slightly lighter, easier to fit to your frame and will cope fine with occasional short steep climbs. sells the SWXH in a 20" speed model.
    XD also sells single speed motors, which I haven't yet tested but which I'm sure are good. When you buy from XD you can specify motor speed, motor cable length, get all the associated electric parts, and they can supply all spare parts for the motor, which other suppliers can't, e.g. XD will sell you a replacement armature, which no-one else does to my knowledge.
    XD may sell motors in a rim, I'm not sure - it's expensive to ship whole wheels. If you do lace your own wheel, you certainly won't need 12g spokes - I've never used any 12g. I've had excellent results with 14g spokes on all sizes of motor and rim, but I do use spoke head washers. See my page on this:
    If you want to regulate your bike speed strictly, the safest way is to use a controller with an LCD, such as XD supply with their motors. It is easy to program the maximum speed in the LCD, and also to use a pedelec sensor, which I believe is the European requirement.
    If you are using these motors within their specifications (36v, controllers as supplied, etc.) I strongly recommend against changing to steel gears. They are for the Americans who over-volt and over-amp motors to go at high speeds without pedalling. The nylon gears as manufactured are just right: they self-lubricate and don't wear the steel gears, they are quiet, they fit perfectly, and they can be replaced when they fail after a very long time. XD sells spare parts for all their motors. You can also get replacement nylon gears for Bafang motors at I have a box full of replacement gears in my stock, but have only ever replaced nylon gears in one single speed motor, and twice replaced the nylon sun gear in XD 2speed motors before XD changed to a better gear material (and we've done well over 10,000km with long steep climbing on 2 XD 2speed motors). So don't worry about the nylon gears.
    Good luck with your project!

    1. I followed your recommendations, thank you. I found a complete kit with one gear motor. I am using the smallest bottle pack, a 10s2p, 7 Ah battery, that weighs 1.3 kg. The total weight of the bike is now just under 20 kg, which is reasonable, considering that I have to take it upstairs. Regular daily trip is about 9 km, and I have a reasonable autonomy of 20 km. After that, the juice drops too low and although the battery is not dead, it needs charging. Also, worth mentioning, I weigh about 90 kg, plus my laptop bag, say the total gross weight does not exceed 120 kg in the winter.

      After a year or so, I have about 2000 km with it, the motor is a little noisy but works just fine. I use PAS level 2 on flat and when climbing, I use the 1st speed on the rear hub and the throttle to help me on the steepest part of climbing (less than a minute, about 50 m, speed about 7-8 km/h). A little bit of effort on my legs, nothing serious.
      On cold days (-10 C) I keep the battery inside and put it on the bike only when I go, so I did not have significant fluctuations of autonomy between winter and summer.

      The motor is mounted on the front wheel (20') and you need to be a little careful at spinning on wet. Using a low level of assistance may help. I also rode on thin snow, sometimes on very thin ice, and the bike was pretty controllable.

      Though I have not a Xiongda, I hope these information will be useful for other readers so that they could personalize their configuration. And, of course, I don't recommend riding on snow or icy roads. If you don't trust it, don't ride it.

  19. Bruce. This is not about their 2 speed motors but Xiongda have recently released the ytx 06 - a geared hub that at 1.3kg has to be one of the lightest around.
    Some basic details sent through by Bonnie (their website has yet to be updated)
    YTW-06, rated 24V250W, 36V250W, 48V250W. hall sensor version and non hall sensor version both available.
    1,3kg, maximum gear ratio 17.5, maximum torque 40N.m
    Controller maximum current 11amps.
    Front disc-brake 100mm
    rear disc-brake & freewheels 135mm
    dia 101mm
    Could be of particular interest to folding bike owners

    1. Thanks David, I didn't know about that motor. A max controller current of 11A is quite low - most 250w controllers I've tried max at 15A. I expect this would be low powered and thus high range - good as you say for folding bikes. I should try one!

  20. Hi Bruce, Thank you for sharing what you are learning in your journey with ebikes. I have really enjoyed reading your blog which has help me understand more about them and their motors. This info on the 2 speed motors is very helpful.
    I have a 36v 250w Fat bike which I really enjoy riding so much that my car only get used about once a week. I live in Christchurch and most of my riding is on the road and sometimes off road on tracks. It handle the slopes on some hills reasonably but the extra steep bits my 74 years old legs struggle to me going.
    Two of my friends have mid drives and they can handle those steep bits better.
    The front forks of my bike has 140mm dropout gap and I was thinking about putting a 2 speed motor in the front wheel. I have spoken to Bonnie, she has been very helpful.
    They have a 145mm rear motor with disc brake that I could modify to fit the front wheel.
    The motor is so small you would hardly notice it in a 26 x 4 fat tire. I’m hoping it would give me the help I need on the steeper slopes. I have also thought of adding a mid drive but the 2 speed hub is more affordable. Do you know if it free wheels okay when not powered. I would like to use it as needed.
    I would appreciate any thoughts you have about what want do.
    Thanks again for a great Blog.

    Cheers Stewart

    1. Hello Stewart, thanks for your kind feedback.
      The XD 2-speed motors certainly freewheel when not powered, no problems. Same with all geared hub motors.
      Putting a rear motor in your 140mm dropouts should be achievable. Main thing would be to align the brake disc with the caliper, but I don't know the disc spacing on a Fat bike hub.
      The other thing with putting a hub motor in your front forks would be to manage the torque on the axle without damaging the dropouts. I should put a photo on my blog above of my most recent torque arm on my front Xiongda 2-speed: the fork dropouts were getting splayed by the torque washers. If you have suspension forks they may have more fragile dropouts - unless they are thru-axle?
      Front motors are very good on the road: we have a few front motor bikes in the family fleet, and I've made several for friends. They can be annoying on steep dirt climbs tho, where they tend to spin the wheel. By steep I mean 15% or more - like our driveway. Perhaps a Fat bike would offer better traction?
      For dirt, rear hub motors are ideal, but then you have to stick with 7 speeds. This will fit with an 8-speed shifter (same spacings), but if you have 9 or 10 you might need to change shifter. If you have 1x gearing (single front sprocket) a 7 speed spin-on cluster gives you a limited range.
      In summary, a front hub motor would certainly give you a good boost, and you would learn how to manage the torque on slippery steep situations (at worst there is no shame in getting off your bike and walking up a steep hill!). The XD 2-speed is certainly low cost and repairable if it gives any trouble (I'm posting a new repair story currently). Main cost is always the battery.

  21. Hi Bruce, Thank you for your prompt reply your helpful thoughts about my project. Bonnie has sent me drawings of the motor and I have worked out that: 1. 4mm spacer on left side axel. 2. 8mm spacer between motor and brake disc. 3. Tap 10mm more thread on the right side axel.
    I should be able to get it to fit and aligned.
    The forks are suspension and the drop outs are 10mm thick. Do you think I would still need a torque arm? I have 7 gears on the back. I do have a second battery which I can carry in my small pack but I was thinking of running the 2 motors off the one battery.
    Thanks for your help and have a great week end.

    1. You're planning to run 2 motors? The motors draw up to about 15A each. It is possible to run them off one battery, but it needs to be able to deliver the total amps. Many batteries (or their BMS) can't do that much current, so check the battery specs.
      Sounds like a good plan with the front axle spacing.
      I would be cautious about the torque in the front dropouts - with suspension forks they don't bend, they can break. I would consider making a torque arm, but you know the forks better than me.
      I'm interested in how you go with the project, I hope you post some pictures.

  22. Hi Bruce,
    Thanks again for your helpful comments. I hadn’t thought about the max amps and I guess that the 36v battery is probably unlikely to cope with 30amps. Can’t seem to find any specs on it.
    It’s a pity I don’t really want to mount the other battery on the bike.
    The torque arm looks like a wise idea.
    Thank you

  23. Hi Bruce, I forgot to ask. What would happen if the battery couldn’t handle the 30 amps?

  24. Hi Bruce, I was in contact with Bonnie from Xiongda yesterday and ask me to say Hi from her.

    I have decided to find a switch so that I can switch the power from one controller to the other. I’ll probably connect the second battery later.
    How do you post pictures?

    1. Hello Stewart, thanks for passing on message from Bonnie. It's great to have her helpfulness and good english.
      The risk in over-amping a battery is either damaging the BMS (the circuit board that protects the cells) or the cells themselves. We use a few types of battery, some have Headway cells (from that can deliver high currents no problem, but if you were planning to draw 30A continuous you'd need to order one with a higher amp BMS. So sometimes the cells can do the current but the BMS can't. A lot of batteries use 18650 cells that can't do high currents.
      Switching batteries is interesting, would need a switch or relay that can do 15A.
      Posting pictures: if you don't have a blog, you can post pictures on your Google account: Google photos; and share them.

  25. Hi Bruce Thanks for your reply. I have found that sometimes the ideas I have are not always practical or easy. Regarding the switching of the power for the 2 controllers. I wonder if I put 15 amp breaker switch between the battery and the controllers as a safety backup in case I accidentally have them both on at the same time. Then use the switches on the handle bar to turn the power on and off to each controller.
    I would value your comments.

  26. Hi Bruce,
    Tx for sharing your xp,
    I wonder if you could help me here, i read all this post and i also saw one or 2 topic on ES about it but firts i need to ask you these.

    I want to do touring with trailer total WEIGHT including me : almost 270 lbs. 26 inch wheel probably .
    I do not need speed.
    i need to be able to go up the hills without damaging motor.
    i will not pedal very strongly

    Mid drive would be best solutionit seems but too expensive so i was looking atq100ccst but some say it is not strong enough for my needs. Some say 500w bmp could do it some say no.
    personnaly i could pedal in slowest gear an add the motor power or pedal with same force with motor power on less slow gear. i just want to go up hill with my cargo and and not best shape, i have time and will mostly only use motor for hills.

    when you say you have a box of bafang burned, are you talking about 250w 350w or 500w bmp?

    Could you share me you experience with the following like compare Bafang 48V500W 201 rpm( CST Rear Driving Hub Motor 500w vs 2speed(unknow rpm speed?) xionda and maybe vsQ100C 201rpm CST 36V350W 32-hole Rear 100 cst?
    remember i'll have 270 lbs total and i cannot pedal very hard.

    i am confuse because bmp is biggers so less supposed to heat but some say it will burn since going uphill slowly..
    some say xionda is better at slower speed but weacker, some say xionda equals q100c! lol i dont know what to choose.

    Also why do you put your motor front wheel? why not rear for better traction. lot of question, sorry haha

  27. i forgot to mention that since ill do most of me biking without using the motor , minimal drag is important, very important.

    Also i might be good to say that for one bmpcassette 500w it costs 200 dol. for 200 i can get 1q100 cst plus 1q100. and for 250 i can get one q100 cst plus 1 bmp2. For 450 there is the cyclone mid

    1. Hello A Human, I'm sorry not to reply, I stopped receiving notifications of comments.
      I think an XD 2 speed would work well for your touring needs. Just be careful of long, slow climbs: stop and rest or walk the bike with motor assistance if you're climbing a very long hill (more than 10 minutes maybe).
      The other 250w motors would be fine on flat roads and short hills, but might burn out on long hills.
      All my burnt motors are 250w motors, mostly Bafang SWXK and SWXH.
      I've never had any problem with a BPM, they are very strong. What causes problems with a Bafang BPM or a CST is using high electrical power - high voltage or high amperage, trying to get high speed. This burns motors and breaks mechanical parts. High power also gives you a short battery range. I use Code 12 BPM at 36v, 18A controller, which is strong, slow and durable.
      I use front motors on some bikes with rear hub gears - hub gears are so nice to use, and good for riders who get confused by derailleur gears. However most of our hub motors are rear motors, which is better on steep, dirt roads like we have here.
      Good luck with your touring, Bruce.

    2. hi Are you saying that a bmp500w would work as wellon steep hills as xiongda ? if yes maybe i would choose bmp becaus it allows to go faster. if yes what no of code of bmp cst would you recommand?

    3. A code 12 BPM in 26" wheel, 36v, would be faster on steeper hills, as it is a more powerful motor. However it would be slower on flat ground, as it has a max speed of about 24km/h. A code 10 would be faster on flatter hills, but might get hot on long steep hills. Have a look at my BPM review on this page:

  28. Bruce, I took your advice and went with the front hub Bafang BPM motor and couldn't be happier. We have 1500 miles on it with no problems. It gets the tandem up hills and cruises on flats easily. I bought the eyelet attached torque arms from Grin because the dropouts were spreading with the torque washers.We have rode 50 miles on a tour recently,pretty good range for the 36v 13ah battery pulling that weight.
    I have been reading about torque sensing pas. We have the cadence one,which works just fine. Is there any benefit to changing over? Thanks again for steering us in the right direction. Paul

  29. Hello Paul, sorry about not replying, my comment notifications stopped. I'm pleased you have a good setup with the front BPM. 50 miles is very good for a BPM on one charge, well done!
    I would recommend against the torque sensor. The only reason I use a PAS is so I can reduce power level and increase battery range - the throttle doesn't do this well. Adding a torque sensor seems to me like increasing cost and complexity, when you already have adequate control. I'm keen on reliable, resilient, repairable and low cost.

    1. try a torque sensor...not can controll your power usage through it in any asist level thus increasing your might think you have controll through your display levels and you do but with torqe you have micro management on top of that.the cadence sensor is on off..the torqe sensor is on of or any thing in between.

  30. Hello Bruce, Can an XD Mini Front Hub operate in a coordinated tandem with a Rear Hub such as a MAC or Bafang? Primarily on steep climbs. Thanks

  31. Hello Gary, my only experience of having 2 motors on one cycle is described in this post:
    In this case 2 controllers of the same model, driving same model motors, were controlled by one throttle, which works well.
    I expect your idea would work well if you're using a throttle (I don't know if it would work with a PAS), both controllers use the same throttle voltage (I expect so), and you have a battery arrangement that copes with 2 loads (2 batteries or one with high current cells and BMS). You could even use a throttle for the front motor and PAS for the back (or another mix). The effectiveness would depend somewhat on the torque and speed characteristics of each motor, e.g. one motor might be cooking while the other is working fine.
    Overall I think it's a good idea. I was thinking of trying 2 motors until I found the 2-speed XD. I thought of switching from a high speed cruising motor in one wheel to a low speed climbing motor in the other wheel when I got to the long climbs, rather than using both at once. However both at once could be good, keeping both motors at a more efficient speed, if they match alright and you have adequate battery power.

  32. After reading your very helpful blog Bruce l made some changes to my bike. I have a fat bike with 250 watt rear hub motor and I have added a 250w XD 2 speed motor to the front wheel. I use 2 controllers and 2 batteries. I find the combination works well together. I ride mostly on the flat but the front motor helps when riding up hills. I would publish a photo but not sure how to add a link to this. Cheers Stewart

    1. Thanks for your update Stewart, and sorry, I just realised I didn't reply to an old comment from you. How do you control the 2 motors? Do you have 2 throttles?
      Perhaps you could upload photos to your google account? There are various links that appear from the icons in the top right of the screen when you're on blogger or anything else Google.

    2. Thanks for your reply Bruce. I have 2 throttles plus 2 pas sensors. I will post some photos when I work out how to do it on my iPad. I don’t see any icons on the top right of my screen.

  33. Thanks for all your post about your experience with XD 2 speed and Bafang motors. I've read them all several times. Yours was some of the best information I found. I'm trying to figure out which to use on our recumbent tandem. I can't use a front mount because I need to remove the front wheel for out bike rack. The hills are our biggest challenge here in SE Pennsylvania, 15% grade. Hence the XD 2 speed has my attention. Jane and Paul seem to do fine with a hub motor on their tandem. My Rear wheel is 26", 145mm drop out, 9 speed cluster rim brakes and a drag brake on the left side. I would assistance up to 32km/h. So, which to use XD 2 speed or a Hub motor. The following Bafang looks interesting but I can't find where to buy one. or this one. I would appreciate your thoughts or comments.

    1. Hello Terry, a tandem on 15% slopes is a significant vehicle to push along!
      Re front hub motor: the Xiongda (XD) motors have a plug in the cable, so they can be removed fairly easily. However you’d need some way to manage the high torque in your dropouts (like a torque plate or lever), and a high torque hub motor probably wouldn’t work in suspension forks with aluminium or magnesium dropouts.
      Re rim brakes on a heavy tandem descending 15% slopes: take care! If your descents are long, you’ll be putting a lot of heat into your rims, and risking blowing off a tyre. This is a common cause of serious bike crashes on our mountain - when it happened to me I was lucky to only lose a tyre and tube. I put at least one disc brake on our bikes to avoid heating the rims - it also gives you a long rim life: rim brakes wear thru the rim walls
      Re the Bafang hub motor you link to: roller brakes are a great brake for city bikes in flat places, requiring very little maintenance, but I’d be cautious about using them for heavy braking needs as I don’t think they cope with much heat. I don’t know where you’d get this model with the roller brake. The motor looks like a version of the Bafang BPM, a strong, single speed hub motor that comes in a few speeds. You’d need to choose a suitable speed (see my post at ).
      The Bafang you link to, the BPM or the XD rear motors take spin-on clusters, that are generally limited to 7 speeds, and lower ranges than cassettes. To use one, you’d need to change your rear shifter to a 7 or 8 speed shifter (have the same spacing).
      An option worth you considering is a Bafang mid-drive motor: BBS01 or BBS02. These are good motors, modest cost, repairable, and may be able to fit on your bottom bracket. Our son has installed many of these in cargo bikes. They can use up chains and sprockets faster than a hub motor, but this isn’t a deal-breaker.
      Good luck!

    2. Hello Bruce, The hills are not all 15%. We just happen to live at the top of one, it is short, and so far we have avoided it by going another direction. But we still do have many hills. I had considered a mid-drive and I think it would fit on the Captain's pedals. The stoker has a three speed chain ring plus a chain ring to connect to the captain. I was not sure I could make a mid drive work at the stoker position. Mid-drive would allow me to keep my current front and rear rim brakes and rear drag brake. I was concerned about the extra stress on the chains and gears with two people pedaling and the mid drive adding torque. But, chains and gears are not that expensive. So for a heavy bikes and hills, what would be your first choice? XD 2 speed, mid-drive, or a BPM motor? Our bike and riders total a 158kg and we do pedal. We are just looking for some help with the hills. BTW our bike is a Vision tandem recumbent. Thanks

    3. That looks like a very long bike! I don't imagine it fits on the back of a hatchback or in a commuter train.
      I think the mid drive would probably require the least downgrading of your gear, and have the highest chance of meeting your expectations. Once you have one in your hand, you could consider whether it might fit in the stoker bottom bracket, but I think it likely to fit on the captain's pedals. The other option would be a BPM code 10 rear hub, plus changing to 7 speed cluster.

    4. I actually do haul it on the back or our Nissan Rouge, a small hatchback crossover, with a rack by Draftmaster which mounts it vertically. You can see a picture of one here.
      In a commuter train, probably not. Thanks for you input. Mid-drive was my original plan until someone said I would have too many chain drive issues. BTW, Bonnie from xiongdamotor says they have a motor with a 9 speed cassette but I would loose my drag brake. The BPM motor that may work is the g070500r. Then I would have my rim brakes and roller brake and the power ratings are pretty strong, but I can't seem to find one. Anyway, thanks much for your insights.

  34. Do these motors come laced into a rim? If not, how do you get the right size and gauge of spokes? I really would like to buy one. I just want to make sure I know how to lace it on to my tire. Thanks.

    1. Xiongda do sell some motors laced into a rim, it would be best to write and ask. There is a contact page at .
      If you would like to build your own wheel, I have a page on how to:

  35. HI how to attache a burley coho xc trailer on these 12mm axle ? any pieces adapter or anything? tx

    1. Hello, the easy way to solve this would be to use a front motor and keep a standard rear wheel that can take the Burley wheel nuts or skewer. When I assembled my first electric bike it was on this same Dahon frame shown above, and using a front motor I was able to continue hauling my BOB single wheel trailer (very similar to the Burley) around the mountain. This worked very well except on steep uphill dirt tracks where the front motor would lose traction. I stopped using the BOB trailer when I put together a cargo bike with an Xtracycle kit. If you want to use a rear motor, then you'd probably need to make modifications to the rear dropouts. We frequently make rear dropout modifications: adding disc brake mounts, adding derailleur mounts, changing to thru-axle, etc.. This is pretty easy on steel frames where you cut out a piece of 4 or 5mm steel plate to whatever shape you need and braze or arc weld it on. It would be possible with an aluminium frame to make a plate that served as a torque plate for the motor axle and carried the trailer nuts as well. It depends on the available bush engineering capability!

  36. Hi Bruce wich front wheel hub motor would you suggest , i imagine it would be one with some good torq at the same time going into 100mm front drop out. my bike is norco yorkville.
    could you tell me what you understand of the problem im facing ? because i m trying to follow you when you say a modification to drop out would be a solution... can you explain . what i see is that burley coho uses ball nutx (female) that do not fit the male motor axel with wire inside from xiongda.this seems like the problem do you agree?
    =axle is round 12mm, flat 10mm, which is the standard bike fork'd dimension. thread is 1.25 type. total axle 202mm

    1. It looks like the Yorkville has steel forks, so is likely to cope with a front hub motor. You may still find you need to make or get a torque washer to stop the motor axle torque from spreading the fork dropouts.
      What hub motor I’d suggest would depend on what country you usually ride in. The Xiongda 2 speed is good if you have steep hills - is 110mm wide so requires bending the forks a little. A single speed Xiongda or Bafang is fine (and doesn’t require fork mods) if you are on flat ground with slight or short hills. A Bafang BBS mid-drive is faster and fancier but more expensive to buy and run and might mess with the gears.
      If you use a front hub motor you won’t need to do any engineering on the back dropouts, you could just get a QR skewer with the Coho balls on the ends.
      Does that make sense?

  37. Hi Bruce. You are a tremendous resource, but I fear I may have to tax you even farther, if you are willing. I purchase an XD 2-speed back in 2017, and immediately had a stroke, which put a stop to the project. I am now fairly well, but getting old, and wish to complete it before I am altogether too old. I have found a cycle technician who is willing to do the job, and I have all the hardware. However, I have mislaid the documentation. Although the kit can only go together one way, the tech wants some info on setting up the LCD etc, and Bonnie tells me she does not have installation manual (presumably she means for these early models. Your blog will help, but can you help with any documentation, please? My technician will no doubt thank you. As do I.
    Tim Cusack
    Sunshine Coast

  38. Hello Tim, I've added the info I have on the KT controllers used with XD motors to the bottom of my post above. These are scans of paper versions. I hope this helps. You may have another model of controller - I think Lishui was an option some years ago. If you have trouble getting things to work, let me know, as our son is a very good electric bike mechanic.

  39. Dear Bruce.
    I'm building some high end ebikes and a new Maxun One solarbike with gravel carbon frames. I will use the 2 speed motor with disk brakes. For this I will let produce special carbon 110mm carbon front forks see this article:

  40. Dear Bruce. I have run simulations that show that the 2-speed motor works just as well as a mid drive motor: