My best 🚲 E-Bike ⚡ Scooter 🛴 Upgrades 🤓 (i.e. for my foldable Fiido D4S 20 inch 🇨🇳)

Here I will log all upgrades that I have done or that I am planning to do with my E-Bike(s) from China. Most of them will also work for scooters, because (I am sure it does not surprise you that) Chinese E-Bikes are actually much like scooters! I will do simple updates that require almost no tools whatsoever, but also more complex ones where some basic knowledge about electronics could come in handy 😉 (Die deutsche Version 🇩🇪 dieses Artikels findet ihr übrigens hier!)

Chinese bikes and scooters are a good starting point because (almost) everything is modular and can be changed. A Bosch (posh?) E-Bike with a mid drive motor might be much better than a Chinese E-Bike with a hub motor (because with the latter the spokes will break sooner or later). But it will be more difficult to change speed limits for example because motor and controller are not separate. (Of course I plan to stick to the local laws, but for example on steep hills it could be good to have a little extra power!)

At the moment I have the Fiido D4S, a 20 inch foldable e-bike. This is the perfect (not really blank) canvas to add components that I like – not only because of the cheap price… (check out my full review here!) My GF has a cheap Scooter (Link to Video Review).

Fiido D4S (banggood / EU) Fiido D4S (banggood / US) Fiido D4S @


1. Bike Bell

I did some changes to the “cockpit” of the bike:

The bell is important because some pedestrians did not react to the horn. Also the bell of the scooter was the first thing that broke (because it was made of cheap plastic).

At first I tried the bell from Decathlon (the one to the right), but it did not fit:

I found this model on Amazon, it fits a handlebar diameters ranging from 22,2 to 25,4 mm:

sits nicely next to the gear shifter (handlebar gets wider there)
it is full metal (retro-look)

It has a very bright sound, not like the Decathlon bell which sounded little bit nicer… but on the other hand people are finally reacting because it is very loud!

Bell @ Amazon Bell @ Bell @ Bell @

2. Thumb throttle (Throttle Boss)

The Fiido D4S has a twist throttle but my wrist got sore. That’s why I wanted to try a thumb throttle (a scooter usually already has this):

“Throttle Boss”

The jury is still out on what is better… if I want to have a sore wrist or thumb. But anyways to try it out I installed the “Throttle Boss”. In the future I can switch to a real thumb throttle (which would also need less space) but I would need to attach the electronics.

Throttle Boss @ Amazon @ @ @ @ @ Aliexpress

3. Rearview Mirror

I bought this mirror off of Decathlon:

a rearview mirror is a real game-changer, I don’t have turn around all the time

The advantage of this particular model is that (beside being very cheap) it can be mounted on both sides and also below the handlebar. Just be careful that the bike or scooter does not fall… BTW my girlfriend also likes it to use it as a kind of cosmetic mirror 💄 while cycling 😉

There are similar models on Amazon:

M-Wave Mirror (attached to the side) @ Amazon M-Wave Mirror (attached on top) @ Amazon M-Wave (side mounted, M-Wave (handlebar mounted,

4. Ergonomic Grips

I was always annoyed that the stock grips started to rotate. That’s why I bought these ergonomic grips that have screws:

ergonomic grips also improve stability

Make sure to buy “left long” and “right short” (Rohloff/Nexus). (If you want to keep the throttle that is.)

These grips are actually from Ergon but you will find Chinese clones.

left long, right short (Ergon GP1 Rohloff/Nexus)

Ergon GP1 Rohloff/Nexus @ Amazon @ @ @ @ Aliexpress

5. Phone Holder

There is not much space left on the handlebar but I found a phone holder that extends nicely so I can still put my phone:

it extends from the handlebar so it is still possible to put

It is very quick to open and close the clamp:

open red knob to remove phone

On the back there is another knob to change the orientation of the phone. This is also nice if I want to take a picture or make a video without removing it:

change orientation using the red knob

It is an advantage that the holder is made of aluminium but at the same time it could scratch the phone.

But I use a TPU phone cover so no problem. (There are some sticky rubber pads included, but I think they will not stick for very long!)

Phone Holder (Amazon) Phone Holder ( Phone Holder ( Phone Holder ( Phone Holder ( @ Aliexpress

6. Bike Rack

This was my first upgrade. Decathlon has a nice rack (literally 😉 ) for a price that is usually cheaper than you can get a similar item from Amazon.

Amazon Option from M-Wave (also on Ebay/Aliexpress)

Still I want to show you first a rack from Amazon which is meant for disc brakes (which the Decathlon rack is not). Bernd Hess sent me some pictures and wrote me, that he attached it to the frame using the first half of the lower clamp:

Rack for Disc Brake Bikes (Amazon) Rack @ Aliexpress

Still this rack is maybe not perfect because it is not that stable and there are not many attachment points to put panniers on the side with hooks (there are not many places to attach it). This problem I also had with the rack from Decathlon, at least on one side…

Decathlon Rack

Anyways one disadvantage of all these racks is the weight (almost 1kg, but Decathlon is marketing it as “lightweight”) and maybe that the racks sit relatively low:

Bicycle Rack from Decathlon
matching Backlight from Decathlon

I got the idea for this rack from Joe Fallkon from the Fiido e-Bike Owners Group on Facebook (or maybe let’s better say the Fiido Support Group 😉 ). As I said the “problem” is that this rack is not really meant for bikes with disc brakes (and hub motors).

The solution is to use longer screws and hex nuts to extend the clearance on one side (I used 3 extra M5 screws with a length of 30mm, I recommend hex type because tightening them is much easier using an allen key, don’t use the type I used if possible):

Using a counter nut I secured the screw on the frame
For the upper part I put many nuts in between (you don’t need so many), so that the distance is the same both top and bottom.

Note: because the screws stick out it is more difficult to put a bike pannier on this side. But you could add less hex nuts and tighten it more. I will usually just use one pannier bag (on the other side) so this is not really an issue for me.

Anyways this rack is – except for this “detail” – a perfect match for the bike, I can even mount my large Ortlieb panniers and don’t even touch them when pedalling (almost)! If you want to make sure that you have enough clearance for your feet I would recommend the Ortlieb Front-Roller panniers and put them all the way to the back:

Even my big Ortlieb panniers are fitting!!!


Because the rear rack is quite heavy and because I still touch the bags with my feet sometimes (at least when I don’t put it all the way in the back) I had the idea to build a lowrider:

the lowrider is just 300g

It is like a front rack, but much more lightweight. And the front light will not obstructed!

loaded with Ortlieb Front Roller Bags (the big ones also fit!)

It was relatively easy to mount. On the bottom I used the included spacer to have enough clearance for the break calipers.

I used the included spacer… usually I would have needed a M6 screw, but I only had a M5 screw (ca. 16mm length), so I put a nut as well

On the top I used two spacers each:

I 3d printed some spacers (lost some of the spacers included in the package)….
spacers are 6.40 mm inner and 12.90 outer diameter!

This lowrider is of a much lower weight (300g) compared to the rear rack (~1kg). The disadvantage is that I have to put an even load on each side or I will create an imbalance. Also the two parts are not connected, so it is important to tighten the screws or the lowriders can start to rotate outwards… if you want you can bridge the two parts to prevent this…

Bike Rack 20 Inch ( Bike Rack 20 Inch ( Matching Backlights ( Ortlieb Front-Roller Bike Panniers Rack for Disc Brake Bikes (Amazon) Rack @ Aliexpress XLC Lowrider @ Amazon XLC Lowrider @ XLC Lowrider @ XLC Lowrider @ XLC Lowrider @

7. M-Wave Mudguards

I ordered the M-Wave mudguards / fenders. This is a popular choice for 16-20 inch foldable bikes, also for children’s bikes. (There is a version for 12-18 inch as well…)

M-Wave Mudguard Set mounted
Rear Wheel

The mudguards are put on a bracket that is screwed onto the bike frame. One disadvantage of this easy assembly is that a bike thieve could do the opposite and pull them out easily as well…

In the back I used the included screw and washer. The mudguard is simply put on this bracket… the black piece stops the guards from rotating
in the front I put the bracket on the screw that was already there for the front light (it is a little bit wider diameter screw)
It is possible to bend it at the bracket so that it does not touch the wheel… the distance can be adjusted as well
everything is working great to keep the dirt from getting all over my back and jacket 😉

At the moment I am really happy with my purchase! The assembly is really easy, the fenders look cool and they are not heavy at all!

Kotschützer @ Mudguards @ Mudguards @ Mudguards @ Mudguards @

8. Changing the Controller

Changing the controller is kind of specific for my E-Bike (Fiido D4S) but since the Kuteng controller I used is very well known you can apply the knowledge to other project as well. Just the wiring might be different.

My main goal was to increase the torque (i.e. go faster uphill). So I needed to put a controller with more current (Ampere). If I would want to increase speed I would need to connect a 48V instead of a 36V battery (see next chapter).

Describing the controller change in detail made this post too long so I created a separate one: click here to read it

10A KT Controller @ aliexpress 8A KT Controller 7A KT Controller (but has different wiring, see video of Jonas Krug) KT Display (I ordered the one with USB) @ aliexpress

9. New Batteries

I ordered three batteries:

12V is on top, below is 2x 36V
  1. Liitokala 36V 12Ah (to extend the range if added in parallel to the bike battery)
  2. another Liitokala 36V 12Ah (for my girlfriend if she ever buys another e-bike to use instead of her scooter)
  3. LiitoKala 12v 12Ah (to add in series, i.e. to test 48V capabilities)

Warning: on the Littokala 12V I might need to change the BMS and the cables, because the cables are maybe to thin to put the battery in series with the 36V battery… (to many Ampere) so right now I would only recommend to buy a 36V or a 48V battery!

36V 13.6A (10s4p 18650)  –> same size as D4S battery!!! 36V 12Ah Battery @ aliexpress

I wrote a separate post on how I upgraded the battery: click here to read it!

10. 58t chainring

My foldable E-Bike can go higher speeds but it gets difficult to pedal at that speed, I look like a hamster. As a remedy for this I want to install a bigger 58t chainring:

Litepro 58t
Size Comparison
58t 130BCD
Crank Set

This will make it more difficult to go uphill. But you can always use the throttle, or also replace the rear derailleur and the flywheel if you want.

Changing the chainring

For removing the crank you need a crank removal tool:

crank removal tool

It is good to buy a cassette removal toolkit because sooner or later you will need it anyways:

you can buy all tools together at a cheap price

Here is another nice tutorial about changing the crank:

Note: Don’t buy this style of chainring, you will need a special kind of chain so that it does not fall off (it could work if you have a thinner chain, for example with the Fiido D2):

don’t buy this!

Changing the chain

It is recommended to also replace the chain with a longer one (you can keep the old chain for testing, it will work but it is not perfect):


The KMC chain has 116 Links (I used the full length):

116 Links

To remove the old chain you will need the bicyce chain remover tool. It was included in my toolkit. (My old chain did not have a missing link, because then it would be easier to break it!)

I put an old wire to release tension from the chain links where I wanted to break the chain.
I put the chain into the chain removal tool and tighten it to push out the pin
Now I can twist out the chain (chain pin is not pushed out completely)

Note: At first there will be resistance when tightening the chain removal tool. Then it get’s easier. It is recommended to stop when it is getting harder again so that the chain pin is not pushed out completely. That way you can still close the chain in theory…

Adding the new chain was easier because of the missing link:

Missing Link
After putting the missing link…
…I pulled a little bit with my hands so that the missing link stays in place
just push the pedal hard and the missing link will close

Cassette Removal Toolkit (Amazon) Toolkit @ Buy Crank (Aliexpress) Chainring (choose 58t) KMC Chain (choose X8) Multipurpose Grease (for bearings, not for the chain!) WD40 (for chain) 16mm wrench (to remove pedals and for crank puller) 8mm allen key (for screw) Shimano SL-M315 Rapidfire Plus 7 speed Shimano Altus RD-M310 Derailleur DNP 11-34T Flywheel

11. Transport bag

I bought a transport bag so that the bike is less bulky when I go with public transport. In Austria bike places are limited in fast trains but if I go with a folded bike it is free. Also for the car this is very practical.

There is also a version for scooters:

I bought this 20 inch tote bag (I will also link the 26 inch version which has more space below and which I would recommend, esp. if you install the upgrades in this guide):

bag is very compact when folded

First I fold the bike. Because I have a rack installed the bike is more wide folded. That’s why I put the handlebar outside and not inside the bike (i.e. not between the wheels):

don’t put stress on the zippers when closing or they will eventually break

When closing the zippers I start with where the bike has been folded and put the bike a little bit back so I don’t force the zippers.

The bag is very cheap that’s why the zippers are not heavy duty. When I close the back zipper (where the wheels are) I push the bike forward again to the already closed zippers, again to avoid putting stress on the zippers. (The 26 inch version should provide more space, I will link it below.)

my bike fits even with my bike rack

I could also push down the saddle and remove the handlebar completely (put it into bubblewrap) and make everything even more compact.

With a more compact bike like the D11/Fiido X and without a rack it would be a much easier fit.

The bike is now as heavy as before (it is an e-bike after all). But it is much easier to carry because it is much less bulky.

You also have to consider that the bag is ~1 kg which adds to the total weight. If the zippers would be stronger and the bag beefier everything would be even harder to carry..

At first I wanted the bag for my gf so that her (future) bike is easier to carry for her, but I think she still needs a bike that is much more lightweight… (Fiido X?)

still heavy but easier to carry

Anyways all this is important for trains because the corridors are so narrow and without the bag it would be very difficult to got here. Also you keep the car clean and tidy.

Rhinowalk 20 inch Transport Bag (Amazon, buy the version for foldable bikes) Rhinowalk 26 inch Transport Bag (recommended for D4S, esp. if you upgrade tires/rack/etc., look for the version for foldable bikes) Rhinowalk Transport Bag for Scooters

12. Schwalbe Big Ben Plus Tyres

This is one of the most important updates because the Schwalbe balloon tyres give a much more comfy ride, even without suspension fork or seatpost (when inflated to 2 bars). This converts the bike almost into a fat-bike.

Schwalbe Big Ben Plus 55-406 (20×2,15′)
Schwalbe Big Ben Plus 55-406 (20×2,15′)

Please click here for my full review & installation how-to of the Schwalbe Balloon tires!

Schwalbe Big Ben Plus 55-406 (Amazon) Schwalbe Big Ben Plus 55-406 ( Schwalbe Big Ben Plus 55-406 ( Schwalbe Big Ben Plus 55-406 ( Inner Tubes (Amazon, look for 20×2,15′) Toplink Joeblow Sport Pump (Amazon)

13. Alarm

I thought a bike alarm would be a good idea to protect my scooter bike (with all the upgrades I have made)… here you can see my gf trying to steal my bike:

actually I had to put the alarm into bubble wrap because it was too loud… (and we put cotton in our ears)

I put the alarm in the black box I printed with my 3d printer… (Here you can read everything about it!)

It is connected to the internal bike battery, but you can also buy a rechargable version integrated in the bike light for example:

Internal Alarm (Amazon) Internal Alarm ( Internal Alarm ( Internal Alarm ( Alarm + Light (Amazon) Alarm + Light ( Alarm + Light ( Alarm + Light (

14. GPS

I use the GPS tracker from SinoTrack:

Please click here for my full review and setup guide for this neat little device!

GPS Tracker 2G (Amazon)

15. Samsung SmartTag Plus (and Apple AirTag)

A GPS Tracker is cumbersome to install and use (esp. because of its size it is difficult to hide). That’s why I tested the Samsung SmartTag as an alternative:

Please read my full review here!

Samsung SmartTag Plus @ Amazon Samsung SmartTag Plus @ Samsung SmartTag @ Samsung SmartTag Plus @ Samsung SmartTag Plus @ Apple AirTag @ Amazon Apple AirTag @ Apple AirTag @ Apple AirTag @ Apple AirTag @

16. Kickstand

I had to replace the kickstand, because the pedals where always hitting it when reversing and finally it broke.

scratch marks where the pedals were hitting the stand

Also very annoying was the “Gong” sound when closing it, because it was hitting the brake disc.

The new kickstand is much better, it solves these issues but the bike is more upright now… maybe I need to shorten the lower part.

I used felt pads that are for furniture, the included spacer was too thick
new kickstand: the bike is more upright but it is still ok,
I just have to be careful when I put luggage on the opposite side

Note: In the meantime I put the kickstand more to the back (it is not possible all the way to the back because there is a loop for the motor cable). Because when I was not careful, I was hitting the pedal with my heel… well nothing is perfect 😉 (well it is working now for me I have shoe size EU 43)

Black Kickstand @ Amazon White Kickstand @ Amazon Black Kickstand @ White Kickstand @ Black Kickstand @ White Kickstand @ Black Kickstand @ White Kickstand @ Black Kickstand @ White Kickstand @ Kickstand @ Aliexpress

To be continued…

Here you can see a list of my future upgrades:

  1. ergonomic handlebar (but be careful that the cables are long enough)
  2. better breaks (Shimano m375)
  3. Suspension fork (front)
  4. Suspension Seatpost (ok if you are smaller than ca. 170cm, otherwise try to find 50cm length) + Adapter 31,6 to 33,9

Please check back often, I will try to make regular updates to my list!

Maybe you are thinking now: Why the hell don’t you buy a bike (or scooter) that has everything already? But like I said in the beginning such a bike is much harder to change and above all I can learn a lot from DIY! So don’t think twice and have fun!

Fiido D4S (banggood / EU) Fiido D4S (banggood / US) Fiido D4S @

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Sigma 16mm 1.4
Sony 35mm 1.8
Samyang 12mm 2.0
Feelworld Master MA7
Smaller monitor
Rode VideoMicro
Mini Tripod
Travel Tripod
Small LED-Light
Light #1 (powerful)
Light #2 (Bi-Color)
Softbox for this light
Light tent/box
DJI Osmo Action
GoPro 9
Invisible Selfie Stick
Mavic mini 2 drone
Mavic Air 2
for photo and video:
Fuji XT-4
Fuji Telezoom
Entry level camera (Canon)

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      1. Wow what a post!! Thanks for sharing 🙂
        I’m considering to get an ebike to go to work (20km) and I’d say the Fiido is winning 💪

        Have you thought about making the battery portable?

        1. thanks jose, d4s is good because you can unlock the speed limit
          vladu makes 3d print to remove battery:
          I did not consider it because I have to carry my bike into my appartment anyways (because not safe downstairs) but for bike trips it could be nice if there is a safe ppace to put it downstairs 👍

  1. Hi! Such a great post. Question: Have you changed your chain ring to the larger ring? If so, how is it to ride? I am wondering if it is worthwhile. Also, you list the Shimano gear shifters in that part of the post, but I don’t see why they are relevant, you didn’t change the shifters did you?
    Finally, any chance of a video explaining how to do it on the D4S?

    1. Hey David, thanks, appreciate it. Yes I have changed to the larger ring. It is better for higher speeds, I don’t have to pedal like a hamster. Well I still have to pedal little bit fast at top speeds, it is still not like having 27 gears or something of course. That’s why some people also change the shifter, the rear derailleur and the flywheel. This is much more work of course and I did not do it yet, don’t know if I will ever do it, I just listed it (also to myself) as a possible future update. Changing the chainring is not very difficult and I would recommend it. Actually I did not change the chain yet, I have it here on my table but I am lazy (the old chain works with all gears but it is not perfect). Here are some videos I did of the install:
      Let me know if the update works for you if you want!

  2. Thanks for this extremely useful post. I was looking for a rear rack recommendation and now I also have a whole load more ideas!

    1. Hey Russ appreciate it, very nice comment. I am happy to give some ideas but I am also honest because there is not the perfect solution. If you have any question don’t hesitate to ask, I am happy to help!

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