We've been saying it for years: Any product that can have embedded electronics, will (eventually) have embedded electronics. Today we have a new cyborg hitting the teardown table: the Xiaomi MiJia QiCycle Folding Electric Bike. This is the first vehicle on our chopping block, so we’re excited to dive into a whole new class of device. Has Xiaomi managed to make the ever-repairable bicycle smarter, without making it a nightmare for DIY tinkering? Let's get rolling on this teardown and find out!

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This teardown is not a repair guide. To repair your MiJia QiCycle Folding Electric Bike, use our service manual.

  1. Look at you, little mobile friend. Quite stylish from the outside we take a look at the specs:
    • Look at you, little mobile friend. Quite stylish from the outside we take a look at the specs:

      • 250 W, 36 V high-speed motor M108RL from Ananda

      • 0.21 kWh battery (with 20 NCR18650PF Li-ion cells)

      • 45 km of biking power on a single charge

      • Shimano Nexus 3-speed gear hub

      • Torque measurement sensor adjusts power based on your pedaling

      • Trip computer combined with controller to provide real-time stats for speed, distance, power etc.

    Für Europa mit nur 75kg Traglast nicht zu verkaufen.

    Gerhard Hallermayer - Reply

    • Before we get started. Did we mention that this thing is foldable?

    • With a few simple movements it can be folded from ready-to-ride to compact-for-transport.

      • Even with a hub motor and battery, the QiCycle masses only 14.5 kg. That's about two dachshunds, or three cats.

    Add Comment

    • For those of you not familiar with foldable electric bikes, here's another, the classic, yet analogue Brompton folding bicycle, for comparison. (It's a bit more macro than our usual comparisons.)

      • The QiCycle has a smaller wheelbase (870 mm) with smaller tires (16"). The fixed handlebar and saddle max out lower too (bad news, riders over 5'6"/170 cm).

    • The built-in bike computer can switch between four power modes and monitors real-time riding data. (And a smartphone app has a ton of info, too).

    I bought one of this but how can i change LCD language from chinese to english?

    parhamsameni - Reply

    Stessa domanda come si aggiorna a inflese

    . Dolcclod - Reply

    • Enough talk, lets strip this vehicle down starting with the easiest part: the saddle. Two quick-release clamps later it's free!

    • The seat post locks the rear rocker arm in place, so once removed the bike can fold up.

      • The post is labeled with min and max height options, and has a groove along the back. The groove serves to align the post and keeps it from twisting, all bikes should have it!

    • Next unscrew the fancy folding pedals. This mechanism reduces the overall width of the bike when folded.

      • Brompton bikes have had (even fancier) folding pedals for awhile now. Xiaomi may have sought some inspiration there.

    Add Comment

    • The chain runs outside the rear rocker swing, and has a handy rear chain stretcher, making removal pretty simple.

    • The chainring has 52 sprockets whereas the rear hub gear counts 14 sprockets. That gives us a ratio of 1:2.7 in first gear, 1:3.7 in second gear and 1:5 in third gear.

    • The chain itself has 96 links. There's no master link for opening the chain but a standard chain tool can pop out any link.

    So the chain is a single speed Narrow (3/32) or Wide (1/8)?



    fotoreporter_86 - Reply

    • Taking the crank arms off takes a little preparation, a cover must be removed before you can fit the crank puller on. But after that it pops out like any other bike's crank.

    • The next piece of the power conveyance puzzle is the bottom bracket.

    • Again we need a standard bike tool—the cartridge bottom bracket tool—to loosen this piece of hardware.

      • These tools may sound unusual, but they are very common for bike repair and maintenance. Good choice to stay standard, Xiaomi!

    can we replace the bottom bracket with standard ceramic bearing bb out there in the market?

    loren.djohari - Reply

    • A nice feature for the QiCycle is this Shimano Nexus 3-speed hub. We easily dismount the bellcrank and take out the bolt which runs to the inside of the hub.

      • When dismantling the hub, the bike should be in 3rd gear. To adjust it, 2nd gear is the right one.

    • At the opposite end of the bike, we pull off the rubber handle and remove the shifter grip.

    Add Comment

    • The rear wheel has a hub roller brake, a style of drum brake. It is operated by hand brake lever so you can backpedal freely.

      • This is an interesting choice, while it keeps the brakes protected from the elements, they are more likely to skid and overheat on long downhills. In the long run, these brakes should be nearly maintenance-free and only require some lubrication from time to time.

    • We start to fish out the brake cable, but it looks like it's riveted to the hub assembly, and will stay attached at that end.

    • So we loosen the bolt holding the hub to the frame and lift out the 16" wheel with its 28 spokes, 3-gear hub and roller brake, and its trailing brake cable...

    Add Comment

    • Of course we wouldn't be tearing this bike down if it weren't a smart bike. So it's about time we check out the speed sensor.

    • The cable connects under the seat then runs along the frame to the (modular) dropout.

    • We're able to peel the cable out, and free the sensor assembly.

      • The sensor system package that measures the crank torque of the cyclist is either the IDbike TMM4 or something very similar.

    The TMM4 sensor is used JUST to measure crank torque and NOT to detect speed that is measured directly from the sensors inside the motor

    diego - Reply

    • Pushing out the small circuit board, we get to the meat of this miracle measurer:

    • The three wire system is connected with a simple JST connector, not solder. Now that's what we call modular.

    Add Comment

    • Back to something more mechanical we unmount the front brake—a standard dual-pivot side-pull caliper brake.

    • To find more electronic components we aim for the front wheel with its hub gear motor.

    • A simple tug disconnects the hub motor cable so we can finally take out the front wheel.

      • All told, it weighs 2.65 kg, that's nearly 20% of the bike's entire weight.

    Add Comment

    • With the cover lid unscrewed we can push out the source of rotary motion and discover a small circular board behind the rear cover of the motor.

    • Besides distributing power it also has three sensors (every fourth coil) for measuring the speed.

      • 12 coils on the outer ring make the 10 magnets on the center spindle go round and round–260 times per minute. The motor has a continuous output power of 180W and 7.3 Nm of torque.

    • The three gears on the flip side are made of plastic to keep abrasion to a minimum.

    Ist der Hersteller des Motors bekannt bzw. nach dem Öffnen zu Erkennen ?

    Kann es sein, dass der Motor hergestellt wird von:

    Changzhou Huayu Xinfeng Motor ?

    Joerg Bucher - Reply

    Hallo Joerg, den Hersteller des Motors konnten wir bislang noch nicht herausfinden. Die Aufgedruckte Nummer am Motor gab auch keinen Aufschluss über die genaue Herkunft (MV8536VN2C5AN16GF2648). Huayu Xinfeng Motor stellt einige verschiedene Motoren her, jedoch habe ich auf den ersten Blick diesen Motor nicht darunter entdeckt.

    Tobias Isakeit -


    I want to remove the power consumption of the motor and the friction resistance of the front wheel motor. I only use batteries to show time, speed and the use of lights. How does this work?

    MainRoad - Reply

    Please I'm not quite get how to open the hub motor, I've already unscrew 3 screw on the cover lid, still the hub not open, please help.

    Bayu Oktaviantino - Reply

    Please I'm not quite get how to open the hub motor, I've already unscrew 3 screw on the cover lid, still the hub not open, please help.

    MainRoad - Reply

    Why the planetary gears are plastics?

    Does they transfer the power too?

    Googly Head - Reply

    Hi, when looking at the specs for this motor, it clearly says 30Nm, while i know xiaomi has 7,3 Nm in their spec sheet. I think Xiaomi got it wrong and is under selling the torque

    okstor - Reply




    shdd_zm - Reply

    • And now, welcome to the middle of the teardown.

    • We stripped the QiCycle of most of its bike parts. The aluminum skeleton we are left with weighs 5.5 kg which is over a third of the overall weight.

    • We go ahead and pull the main plug from the top tube, enabling us to extract the nervous system linking all the electronic components.

    Add Comment

    • Only 4 Torx screws hold the cover of the bike computer and the 160×128 pixel TFT screen is attached with a simple ZIF connector.

    • On the flip side of the board we find the following chips:

    How to factory reset the trip computer?

    Yen Martinez - Reply

    Same question : How to factory reset the trip computer?

    Because, battery is 100% but computer show 5%, update software failed :-(

    SO no i do not have electrical assistance

    axel ta - Reply

    Ok problem solved with QICYCLE beta software (MC+BMS => ok ; max speed = 30 km/h)

    axel ta -

    Same question, software update failure now MC and BMS show 000-000-00 and i’ve lose electrical assistance

    Clads92 - Reply

    Hi ifixit,

    How did you remove the metal plate that protects the MTK 6261A CPU and the Winbond 25Q128FV CHIP ?

    Best Regards

    JohnDie - Reply

    Carefully ;) but with the help of a side cutter. Removing those shields is not recommended and might effect the function of the chips.

    Tobias Isakeit -

    Ok i took it off :)

    But it's not a chip W25Q128FV on my board..

    It is written 25LQ128CWIG on chip.

    GigaDevice GD25LQ128CWIG

    I have to do a dump jtag.

    JohnDie - il y a 1 heure

    JohnDie - Reply

    行车电脑不能开启,拆开后通过触摸发现“德州仪器TPS259240 eFuse 带过压保护”温度过高(烫手),这一现象只是eFuse的问题?还是其它部件有问题?


    shdd_zm - Reply

    Hey !! Take a look at this playlist.

    30 minutes, and you will have your translated QiCycle !!

    Michele - Reply

    • We saved the best, or at least the most power-ful, for last—the battery tube!

    • The tube can be removed single-handedly, with just the push of a button, and can be charged in 3 hours with the 5-pin connection on the side.

    • A good amount of the bike's weight is this battery—it weighs 1.46 kg, fully charged of course. ;)

    • The bike's battery capacity measures in at 5800mAh (208.8Wh). For your pointless comparison of the day, that's more than 5 iPad Pro 12.9"!

    Add Comment

    • We begin to pry out the rear light, a cable keeps it in place, but it does give us access to some hidden screws. This in turn grants us access to the internals.

    • This massive umbilical leads from the charging port to the batteries and the BMS (Battery Management System) at the other end, and an LED board behind the rear light.

    • We peel out said circuit board and discover some secrets. This guy controls the rear LED array, as well as some status LEDs along the top of the tube (probably to indicate battery activity).

    Add Comment

    • The main battery compartment is a tough nut to crack. Five screws (hidden by some hard to pry off covers) aren't all that hold this case together.

    • As we finally succeed with some gentle heating and "good vibrations" we snap open the case, breaking one-time-use clips in the process. Bad news for battery cell replacements.

    • We finally reach the prize: 20 Panasonic NCR18650PF Li-Ion batteries! Panasonic is a good (safe) brand, so recharging should be a breeze, even if individual replacement won't be.

      • The battery pack also has a battery management system (BMS) circuit board.

    Add Comment

    • The board is packed with lots of resistors. What sticks out are these components:

      • An ATMEL MEGA 328P Battery Management MCU

      • S11428 33TVF

      • FL12.000 12 MHz quartz crystal oscillator

    • On the flip side we find these:

      • Magnachip MDU1931 single n-channel trench MOSFET (x4)

      • RS2M rectifier

    Add Comment

    • We return to the bike's body to do a bit more disassembly before tackling the final electronics.

    • The bike's main hinge—the rear swing fork—is held to the top tube with a simple Allen bolt.

    • When detached from the frame we can clearly see the tilted asymmetric hinge.

      • This unique shape allows it to stay in line with the bike when riding, but swing right next to the front wheel when folded.




    shdd_zm - Reply

    • The second important compact-ifier is the foldable handle bar and stem. The mechanism itself is cool, and comes easily apart with the pull of a pin.

    • To take the front fork off the hinge, we make use of the uncommon, but essential, 10 mm allen key, an essential for bike repairs.

      • The front fork is cast as one single part of aluminum and weighs just 0.71 kg, that's not much more than a soccer ball!

    Could you please provide detailed dimensions of the fork?

    Alexey Vavilkin - Reply

    • What's left is the top tube, complete with the headlight and the brain (more on that later).

      • This aluminum center piece weighs only 1.36 kg!

    • With a firm twist of the hand we can unlock the headlight and take it out of its recess.

    • A single cable with a simple connector keeps this high-powered LED well... powered.

    Add Comment

    • The brain control unit is mounted to a handy handle that attaches to the frame with two simple screws.

    • Having removed the screws, we can grab the controller unit by the guide rail and slide it right out.

    • This bike's brain is a single unit electric bike controller by Ananda, a manufacturer of many electric bike components.

    Add Comment

    • Of course "single unit" doesn't mean much to us, we dive in past some standard Phillips screws, and work on prying the stubborn casing open.

      • We grab a Jimmy and iFixit Opening Tools and try to negotiate–without any success, even when heated.

    • We turn our efforts to the side panel, and what we found inside will shock you (people always fall for that, right?)

    • Three boards—bridged by an army of pins—are drowned in gobs of yellowish transparent rubber.

      • We suppose this is to dampen vibration and help dissipate heat to the aluminum casing.

    Add Comment

    • Most of the important components live on the battery pin board, we spy:

    • The rest of the goop-covered boards mostly carry capacitors and other passive components.

    Add Comment

    • And with that, this bike has been folded, unfolded, and torn totally down.

      • Except for the boring bike bits—we're only here for the "electric" parts after all.

    • This layout might be a bit bigger than usual, feel free to take a closer look.

    Nice job, I've just received one of these and am much happier with my purchase after learning about the inside of this sweet ride. Thanks!

    Del Riordan - Reply

    hello the cycle does not react the battery, hard bastane time without load by the shipment and delivery, the loader gives green light parapadeante before connecting it to the battery, I do not know how to make the battery work.

    maogonley - Reply

  2. Final Thoughts
    • Standard bicycle components and tools are used throughout, making repair more accessible.
    • The battery assembly can be removed and replaced with ease.
    • The electronic components can be removed without compromising the bike, extending its life and making recycling easier.
    • The seatpost, frame, and front hub motor are nonstandard, making a replacement a bit more difficult when the manufacturer does not offer them.
    • The battery pack is a complex assembly that makes for wasteful replacement when individual components fail.
    Repairability Score
    Repairability 6 out of 10
    (10 is easiest to repair)


My axiomi qicycle seat post keeps slipping down despite locking d 2 release clamps tightly. Caused a fall from d bike as d seat post slipped and hit d ground jamming d moving bike. How to tighten d 2 clamps to ensure no slippage especially cycling at a higher speed?


Zho - Reply

The quick release clamps can be adjusted by using the bolt on the opposite side of the handle and tightened by closing the handle. The QiCycle is constructed for max 100kg weight. You may also try cleaning the seat post for a better grip (maybe it got a little greasy during the assembly).

Tobias Isakeit -

I am wondering if the two saddle clamps can be replaced. And if so where to find them? Help very much appreciated :).

Jannes - Reply

The saddle clamps should be replaceable with standard quick release clamps of the correct size. Depending on the design the handle might not be curved like the original one and therefore stand off a little bit.

Tobias Isakeit -

Thank you for all the pictures. Unfortunately after a drop of the battery my taillight is not switching on anymore. Do you have detailed pictures of the disassembly of the taillight. Maybe it is only a connector that is loose... Thank you :)

Montie - Reply

Hi Montie, we don't have a separate guide for the back light yet. But to get it off, you need to grab it very tight and turn it counter-clockwise. The rest can be seen on the pictures in step 16 (four screws and the cables inside).

Tobias Isakeit -

Hi Tobias, thanks for the fast reply. I know how to get to the connectors (thanks to your good illustration) but I need to get *into* the light because the connectors which are visible seem to be okay. Obviously I have to peel the red plastic off which is not clipped but sealed. The back (black part) of the light is one single plastic part if I see this right. Any further help would be nice. Should I use a knife? I don"t want to destroy anything...

Montie - Reply

Hi Montie, getting into the light itself without "destroying" it looks quite impossible I guess (we haven't tried it). The light looks as if it is sealed from both sides, front and back.

Tobias Isakeit -


My Charger seems to be dead. Even LED Indicator wont light up and it doesnt charge the bike. Do u have any advice or guide to open it up, or to work the batteryside connector onto another fitting charger?!


Andreas P - Reply

Hi Andreas, unfortunately we haven’t torn down the charger itself. Charging the battery via other means sounds like an experiment I would not recommend unless you know what you are doing.

Tobias Isakeit -

Same with the case you are experiencing, is it now resolved? If so, I would like to get feedback on the issue from you. Thank you

Yosu Hanisusilo -

Someone knows how to bypass/remove/change 20km/h speed limit ?

Thanks in advance


diego - Reply

There is a firmware update. It came automatically to me via the app. I mean I was asked within the app whether I wanted to upgrade the firmware that would lead to 25km/h.

bill depo -

Just FYI: firmware update seems to be possible only by using an Android device, not iOS.

Andrew S. -

I didn’t get any update firmware . what’s the last software version indicated in bicycle info in the app?

Ali Titan -

What does the Max speed mean?

If I'm pedaling quicker than 20km/h then the engine will not help me to reach 30?

Is there mode how can I ride 20km/h without pedaling?

dannique XXII -


I tried to upgrade the Qicycle but it never ask me to upgrade the firmware in the app.

Could you say me which app we have to use ?



I tried with iphone too but it don’t work.

The version of the driving computer is : 1.6

Thx for your help.

Janoyolo -


I just get this bike and I’m very happy with the quality of the model! Your tutorial is great and very clear, I will not hesitate to consult it if needed.

I have one question for you :

I’m 1,85m tall and I have to put the seat at its maximum position in height but that’s fine. The problem comes from the handle which is a bit low.

Do you know if it could be replaced by a foldable adjustable handlebar ? I’ve seen some on the market, and it would solve this issue.

Thanks for your amazing work.


Mourey Leonard - Reply

Yes, it is possible, something like

Although the original stem has much better quality, so I ended up just adding this adapter to make the stem longer:

Andrew S. -

I have another important concern :

My electric motor is not working on my Qicycle.

When I use the different modes with the pushbutton, I’m not feeling any help from the assistance of the motor. The battery works properly, as well as the on-board computer that displays correctly : the battery level, the current speed, the power in Watt and the assistant mode.

The application shows the message : "One issue found : please check the motor line on the left of the front wheel”

I don’t know how to proceed to fix this. Can you help ?

Thank you

Mourey Leonard - Reply

You may want to check the cable on the left hand side of the fork if it is connected properly (see second picture in step 11).

Regarding the height problem in your other comment I’m sorry to tell you that the bike is designed for people under 170cm. The seat post and handle bar post are non-standard components and don’t look like they can be replaced with longer versions.

Tobias Isakeit -

This is not true, there are 3 options:

1) Replace the stem with telescopic one

2) Add the stem adapter

3) Replace the handlebar with curved one

Andrew S. -

Please I'm not quite get how to open the hub motor, I've already unscrew 3 screw on the cover lid, still the hub not open, please help.

Bayu Oktaviantino - Reply

у меня такая же проблема. кажется, что корпус является монолитным. это не так, как там покрыть возможные отвинтите.

Leonid Kazarin -

The lid sits very tight. Try to get a grip through the three holes (for example with two allen wrenches) and turn counterclockwise. (Caution: the lids edge is very sharp)

Tobias Isakeit -

What did you use to open the lid Tobi?

Are you using three allen wrench?

Bayu Oktaviantino -

I used two allen wrenches (short part in the holes long part along the axis) and used the axis as pivot point.

Tobias Isakeit -

Is there a way to buy a battery pack for this bike ? I need one desperately …

Miguel Fonseca - Reply

La bici mi é arrivata con il display del computer di bordo scheggiato,infranto il display una volta acceso non é leggibile.

Come posso ovviare a questo? È sostituibile con un nuovo display?Dove posso trovarlo?


Agostino - Reply

Aliexpress…. 65€ circa!

fotoreporter_86 -

The chain jumped down while I went uphill and only low engine support. How can I avoid this in the future?

Jürgen Weißmann (7ii) - Reply

Hi Jürgen, check the spring on the rear chain stretcher (see step 5). This should provide enough tension for the chain to not jump.

Tobias Isakeit -


What kind of axel and nuts does the front fork have ?

Is it M10 nuts ?

Thank you

Mourey Leonard - Reply

Hi Mourey, I used a size 19 wrench, so its probably M12.

Tobias Isakeit -

hi! great teardown! do you know the dimensions and weight of the batterypack? i'm planning to buy the bike in china and then send the pack in mail, since its not allowed to take the battery in your suitcase or carry-on in airplane.

maurits irizarri van suchtelen - Reply

Hi maurits, the battery pack itself is 46 x 7 x 7 cm (±0.5cm ;) ), weight is 1.46 kg.

Tobias Isakeit -

Thanks! If its not too much trouble, do you know the size of the bike when folded and the saddle removed? To See if i can fit it in a suitcase without completely taking it apart.

maurits irizarri van suchtelen -

Spiegazione al di sopra di ogni aspettativa. Una pecca, manca la spiegazione su come installare la lingua inglese essendo tutto in cinese.

. Dolcclod - Reply

Dai un’occhiata a questa Playlist.

30 min ed avrai il display in Italiano!!

Michele -

help: I update the firmware with android and now the qicycle go fast to 26 km/h, but the led light rear don’t works more!, instead before it’s ok, also the computer on board don’t read the status of the battery, plase help me!! also other peaple have the same problem…

francesco Villeggia - Reply

I have a problem.

When my bike is off, suddenly the engine on for a second and the wheel turns.

This happens more time for a day. Where is the problem? In the controller or in the computer?

Thank you.

Fabio - Reply

Dear Fabio, I have exactly the same problem than you. I have the bike since 2 weeks and even the bike is off, the wheel turns anytime sometimes one turn sometimes more …

Do you fix it?

Thank you bye

Olivier - Reply

Hi everyone,

Did anybody find the right antitheft combination for the QiCycle ?

I’m thinking about the Kryptonite NY M18-WL + some Hexlox to secure the saddle, handlebar and wheels. But as I’m still waiting for the bike to be delivered, I can’t really figure out if Hexlox can be used on these wheels.

Anybody tried or has other ideas ?

Thx !

Léa Gilezo - Reply


Please can someone help me with the gears? I received my bike on the 28th of this month and I have successfully upgraded to latest firmware. The problem I am having is on the 2nd gear when i pedal it feels like it is skipping, it is not pedalling smoothly. 1st and 3rd gear seem fine and don’t skip.

Any ideas how i can fix this? I notice the yellow dot in the nexus gear is not in the correct lines.

Thanks Az

Az Rahman - Reply

This is because you have folded the bike in 2nd or 3rd gear, and pulled the gear cable, you need to fold it ONLY in 1st gear.

To fix it now you have to follow this procedure:

arnaud greusard -


mein Qicyle hat anscheinend leider einen defekt. Das Rad schaltet sich von selber aus obwohl der Akku noch 80% hat und am Akku selber noch 4 LEDs leuchten. Auch das Update konnte ich nicht aufspielen, es wurde mir von keiner App (ich hab so ziemlich alle Apps probiert) angeboten.

Hat einer ähnliche Probleme? Ich gehe davon aus, dass der Akku defekt ist. Bei Lieferung war er komplett leer, also keine Statu-LED am leuchten.

Beste Grüße, Christian

Christian - Reply

I have recorded the issue. If anyone can help?


Az Rahman - Reply

Hi Bobo,

Thanks for the video. I saw this same video earlier today and followed the same steps but I couldn’t get the yellow dot to align in the middle of the 2 lines as shown on the video.

None the less I turned the cable adjustment all the way in and even though the yellow dot isn’t in the middle of the 2 lines it fixed my issue :)


Az Rahman - Reply

Hi, I need to increase the speed of this bycycle, would you help me with the tutorial, the video. Thank you.

Dušan Hojer - Reply

Hi Dusan,

Here is the tutorial:


Az Rahman -

Dears, I just received my bike, the app on android proposed me the upgrade. Since then, The onboard computer shows my battery being empty, the red light doesn’t work anymore also the electric assistance doesn’t work. Any way to do a downgrade of the onboard computer? (as on the battery the 4 led lights are on when testing.)

honer - Reply

Hi Vincent , take a look here >> <<

I solved same issue following the instruction of the user julferber ( see page 2 )

Be patient and good luck ;-)

Bobo - Reply

Hi, i have Qicycle EF1 since october. The bike worked well since yesterday. Since yesterday, the bike has some issues that are a little bit annoying.

I think it may be that the speed meter is broken, so it does not detect that the bike is in motion. (posible issue of hub gear motor measuring speed?)

-Display don't show speed screen when I run with it (in 22km of my travel, only show this is screen 2 times only 10 seconds, and the display show 0 km/h, 0km, 0wat) But all time this screen doesn't appear. Only show battery screen, the same screen when you're stopped.

-The display tur off when I'm ridding, like when the bike is stop. 1 min for default setting. When I press a button when I'm reading, the screen wake up, like when the bike is stop.

- I can't change the power assistence, If i change the bike continue to 150%.

- In some cases, the bicycle offers less assistance and lowers the power alone, just a few seconds, without any reason. The engine continues, but with less power.


doctorase - Reply


You can follow this to fix your problem:

Az Rahman -

Is it possible to put all the pieces into a bagage 31CM*46CM*70CM?

Tao Wang - Reply

Probably not. Bike dimensions folded are: 450x1000x650 mm. See product page, under specifications.

Tobias Isakeit -

Is there a way to remove the speed sensor or trick it to believe it’s going slower than it is?

arnaud greusard - Reply

I mean to increase the top speed past 25kmh which is still a little slow. Or a firmware hack?

arnaud greusard -

hello: I just got the bike and my mother fell with the bike and she hit the screen. I do not know if it has arrived with defect or has been the blow on the screen! The problem is that suddenly the screen turns off and runs out of energy! Sometimes when it is turned off and the lights are on, the back light stays on for a few seconds when the screen is off, until it shuts off completely. I'm about to buy a screen! I could i check in some way that the screen is causing the bike to turn off?

Andrés - Reply

hello: thanks for your previous response. Today, lift the front wheel of the bike, when I was walking. It stopped working. it went out I checked the cables with the (polymeter tester) and the cables are not broken. What do you advise me to do?

Andrés - Reply


i have MC and BMS show 000-000-00 and i’ve lose electrical assistance !!

can not update MC and BMS with QiCycle app official or not :-(

axel ta - Reply

Hi axel take a look here


Bobo -

Salve, sono Vincenzo

ho una qicycle, che negli ultimi giorni mi sta dando problemi, la sento più pesante ed il motore non mi sembra sia scattante come prima.

Da cosa può dipendere? io mi sono accorto di qualche anomalia al cambio, la marcia 3 non entra alla perfezione e la taratura in seconda risulta non corretta, il pallino giallo si trova fuori dalle due estremità di “set” può dipendere da questo? cmq cercando di settarla rimettendo il pallino al centro , ma quando provo a muovere il cavo di riferimento questo non si muove… che posso fare?

grazie a presto.

vinz - Reply

* Why has the control unit 5 pins? It labels plus and minus for the 42V so far so good but what is the e.g. Vlm pin for?

* Also the charging cable has 5 pins. Why is that? The battery has 10 cells in series so I guess it cant be for balancing reasons.

* Where can I find such a connector/socket for the control unit plug?

The reason for my questions are that I am planning to do a 42V battery pack by myself.

Martin Hammer - Reply

Hi guys,

I am experiencing an issue that has been recorded from others as well in the past.

The motor has stopped working since a few days.

The story:

- I had an accident falling off the bike about a month or two ago and since then I have been experiencing problems with the electrical assistance.

- First symptom was that the motor would not work always

The problem here was that the cable attachment under the battery tube on the front ( connecting the motor, battery, Hall sensor etc. had been slightly removed because of the usage and the crash potentially. The problem was fixed after it was properly attached.

bill depo - Reply

To get the motor to work again I had to completely stop the bike so the Watts would go back to 0 and then start again.

bill depo -

- I kind of got used to the above problem but then the motor would not work at all. The display works as usual (showing Battery, Speed & Watts ).

I opened the black cable from the motor as in the post below and found one of the three (the blue one) fat wires inside (out of 9 in total) cut. I then used one of those wire connectors to connect it back and did it successfully. After removing the cable all the way from the motor to the plug before the torque sensor I tested with a digital multimeter that there is conductive path from each pin of the plug leading to the torque sensor with one pin of the central plug (under the battery) and same between the pins of the plug leading to the motor and the central plug again. So, it seems that everything works correctly with the cable.

bill depo -

Doing the self-test within the app for the bike, I got notified that there is a problem with the front wheel and the left side of the cable . As mentioned previously everything has been plugged correctly and fixed the cables.

My only hypothesis is that either:

1. The torque sensor is not functioning properly (I will try cleaning it as per the link I don’t think it is this having a problem though, cause the Watts displayed are in a normal range that the motor would normally work. Same for the speed therefore the problem must be in the motor

2. The motor has a problem. I have unscrewed the 3 lid screws but can’t open the motor at the moment and even then I wouldn’t know what is the problem and how to fix!

3. There is still a problem with the cable or plugs (eg not making proper contact)

What do you think might be the problem and what should I do next?

bill depo -

Hello, it would be possible to replace the wheels with 20 inch wheel?

faisalhok - Reply


few days ago i bought an used Qicycle. The Bike totally has 12km. Outside it’s in a very good condition.

Now i recognized that the wattmeter still shows “0”. I am sure the motor doesn’t function. Now i need some help .

What I did :

-Flashed back original software now it is :

LINPic 003-013-000

MC 005-017-000 (25km/h)

BMS 018-024-023

Firmware 1.6.613

-Checked Akku -> Loading Okay, Lights Okay

-Checked all cable connections (motor left, controller, display, hall sensor)

-Checked intergrated cable if it is broken. All 16 cable contacts give a signal. I post the wiring of the cable for the community. With my plan you can check if the wiring is ok.

what could i do now ? Buy a new motor, how could i check if it is broken ?

Buy a new controller ? Does this make sense, because all seems ok. The Qicycle Software says “bike is Ok”

Buy a new “Hall sensor”, don’t know if this could be the problem…maybe a expert could tell me.

If somebody help me to get a solution i would donate something.


Harald - Reply

Dear Harald,

My integrated cable has more than one pin broken but I couldn’t figure out what wire to check as all 9 wires look intact in appearance. Please send me the wiring color code for pin numbers that are shown in your wring diagram.

Many thanks in advance.

phu dang -

Oh..sorry, at the Moment couldnt find it…

Harald -

hello, problem is solved, changed the torque sensor/ hall sensor and now the motor starts and the wattmeter works.

Harald - Reply

There is a strong resistance on front wheel only when turning reverse (no resistace moving forward). Motor not working although computer provide all the data even the watt usage. Pls assist any feedback would be very much appreciated

lousky007 - Reply

Hi lousky007!

My bike has the same problem too. I tried unplugging the cable from the controller and the front wheel can be turned backwards without such resistance. I did the same procedure to the hall sensor but the prolem remains the same so a malfunctioned sensor could be ruled out. I guess the segment of cable that connects the front wheel motor to the controller may have some broken wire in it. This segment of cable is very tight so don’t turn the front wheel to the left until it stops as it is prone to failure if you overdo. I ordered a new cable and I am waiting for my delivery. Have you successfully fixed it yet? If yes, please tell me the right cause.

Thank you very much.

phu dang -

@phu dang,

sorry i have no color code for the pin numbers, because i only did a measure of the cables. my wiring plan is quite simple you only have to check the numbers of the pins which are wired.

as i wrote above my problem is solved. First problem with the update was an incompatible android smartphone. Changed ist and the update was successful. Second problem was not the wiring, but the hall sensor. Changed it to a new one and evrything was fine.

If you habe broken pins on your cable why don’t you chnage the cable. It costs about 25$ and changing should not be a problem.

Harald - Reply


Thank you very much for your kind reply. The problem my bike is experiencing may be somewhat that relates to the front wheel motor, the controller, the hall sensor, the cable… I have ordered a new cable on Aliexpress and I am waiting for my delivery. But what if I can’t still fix it? I will try replacing with another part by ordering a new one until the problem is resolved. I will let you and everybody in the forum know the exact cause when i have sucessfully fixed it as a way of sharing experience.

Have a good day my friend.

phu dang -

hello phu dang,

best wishes for you to solve the problem. i understand that you are afraid of not finding a solution, for me it was the same. As i said it is easy to check the cable. take my wirking plan and a voltmeter. you can easy do a measure if there is cntact between the poles. As i read in other forums often the hall sensor was the problem. The motor or the platine/chip/controller is rarely the problem. The motor is verry robust. Are there any errors shown when you do checks with the app ? The app should show contact/wiring problems with the motor. In the other forum someone told me to change the hall sensor and he was right.

Harald -

Hello Harald,

I greatly appreciate your kind suggestions and your helpful information. Because at the moment the cable has not been delivered yet so I cannot do anything with my bike. I’m glad to hear that the motor is robust and it seems to immune to malfunction as this part is very expensive. Could you tell me the app you mentioned that can be employed to check problems relating to contacts/wiring with the motor?

Thank you very much and best regards.

phu dang -

Hello Phu Dang,

its the Original App from Mijia .Maybe it is only in Chinese Playstore. You have to sideload the APK, for example here.

The App cant check the motor or the wiring direct. But for me it was so that it showed no error. For other people it showed errors which mostly have to do with wiring in the front to direction of the Motor.

Harald -

Dear Harald,

Thank you very much for your help. I will try the app and let you know what it’s telling later.

Could you send me the address link to buy the torque sensor on aliexpress?

Best Regards.

phu dang -

Hello Phu Dang,

this is the spare part i ordered.

Harald -

Hello Herald,

The item from the link is no longer available. I did google the torque sensor and the LCD monitor but I could not find any items that is available at the moment. OMG this time would be a tough one for me. Do you have another link for those items?

Best Regards

phu dang -

In this link First isahown Not available but if you choose delivery country (for me germany) i am able to put it in the basket. 97 items are available

Harald -

Dear Harald,

I picked Vietnam as the delivery country but the message ”sorry, the product is not available at the moment” kept popping up. I think the best thing I can do now is to wait for the cable assembly to arrive and then decide the next step to do. OMG this is a time-consuming task so I’d better stay calm and wait.

Thank you very much for your kind support.

phu dang -

Hello Herald,

Is it possible to install throttle into this bike?


lowkf - Reply

hello jay,

hahaha i am not a technican for qicycle bikes i am a user as yourself. i think if you are good you could do anything with the bike. here is a video which shows the opposite of a throttle, a mod fro full power

Video only should show that everything is possible, but i don’t know how to do such mods.


Harald -

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