How to Strip down a Bosch GEN 4 E-bike Motor

How to strip down a GEN 4 Bosh motor. DO NOT ATTEMPT THIS WITHOUT WATCHING FIRST. A must watch for anyone that wants to strip one down. (MUST WATCH)
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Website: www.cycle-fast.co.uk

[@leoguzynski]

You've completely convinced me. I'll keep my pricker out of there.

[@TheYorkshireBikeMechanic]

Hi and thanks for watching, wise choice

[@jackdrummond5472]

Great video Dave! Definitely puts me off wanting to ever have to work on this motor but really helpful for me to understand a bit more about what’s inside the motors and what does what!

[@TheYorkshireBikeMechanic]

Hi Jack, that was the main reason for doing the video, for the curious ones. thanks for watching and your comment

[@alasdairhill5166]

Thank you so much,I have rebuilt and replaced every bearing on a gen 2 with no probs due to your kind help and have got a friend with bearings gone on a gen 4. 👍

[@TheYorkshireBikeMechanic]

Thats great you did then gen 2, be careful if you decide to do the gen4, check that it cant be done under warranty first.

[@alasdairhill5166]

Thanks very much but his is nearly 3 years old ,I have taken great notice of your strip and do hope you will follow up with a strip down of the transfer box.I am a mechanical engineer come welder fabricator by trade and have press and can make tooling to strip and replace bearings .It doesn't look any harder than gen 2 so far .

[@FrankBlazeNL]

Superb, very informative. Looks like changing some crank bearings has become quite a mission! Hopefully mine will last a while before this needs to happen. Great video!

[@TheYorkshireBikeMechanic]

Hi, Thanks for watching and your comments

[@wonjat5]

Just to say how much I like your videos, well done for sharing your knowledge and expertise. I think you strike a sensible balance in terms of encouraging bike owners to maintain their machines, at the same time encouraging to recognise their limitations and go to their local bike shop. The Bosch Gen 4 motor strip down was excellent. We have two e bikes Velo de Ville, I look forward to re-racing the motors when they reach that stage. Kind regards 🇦🇺

[@TheYorkshireBikeMechanic]

Hi, Thank you for watching, and thank you for your kind comments, I try to show people a more practical approach so they can decide if it's something they could do, if don't think it is I will say so, you get what you get with me, if you know what I mean. Thanks again

[@TheYorkshireBikeMechanic]

Thank you, I appreciate your comments

[@Ringo300880]

Hello, glad to see you back here recovered. And then right away with this project, which has interested me since the Bosch G4 on the market. Thanks for the information. Greetings from Germany

[@TheYorkshireBikeMechanic]

Thank you, thanks for watching from Germany, one of a few places I would like to visit

[@Ringo300880]

@@TheYorkshireBikeMechanic You are welcome 😁

[@caramba10]

Brilliant video, glad you're getting over Covid and it's good to see you back.

[@TheYorkshireBikeMechanic]

Thank you

[@juhavuorinen7711]

First of all thank you for really outstanding video with a great explanation. My gen 4 motor was out of warranty and I had little play at the crank axle so I decided to replace bearings by myselft after I watched this video but I must say its still quite hard job to do and it took something like 6 hours to get job done. It also required many special tools. When I was disassembling the motor I found that your motor missed one c-clip. When you remove first part of crank case you should have c-clip over the drive cog. I say this because if some one is trying to replace the bearing they must remove that to get drive cog out. Then that drive shaft also misses o-ring which is at midle of the shaft but thats not a big deal. I tried to remove magnet motor without bolts first but its nightmare so I bought threaded rod and used that as bolt. The thread is 5mm x 0,8 which is metric standard I think. Other than that my drive shaft was quite tight to remove from the last bearing so I gently tapped it out without damaging torque sensor. Those bearing from the crank case can be removed with poor mans bearing press by using nuts, sockets and threaded rod. You can press new bearing with old ones. But all in all it is quite time consuming and hard job to disassemble this motor without damage but It can be done thanks to your video.

[@TheYorkshireBikeMechanic]

Hi, thanks for watching and your comments, it's a very trick job and not for the faint hearted. well done.

[@pistolpete938]

Iv got a hibike with this motor in, I can see now why these things are so expensive, I'm not sure id risk taking one to bits myself but its still interesting to see it done properly. Excellent video keep them coming!.

[@TheYorkshireBikeMechanic]

Thank you

[@paulm5025]

So glad you are on the mend and feeling better! 🙏👍

[@TheYorkshireBikeMechanic]

Thank you!

[@claremontinteriorsmw]

Many thanks for a well documented and Good insight into the working of these motors I believe i have the confidence to tackle this if it ever come to it

[@TheYorkshireBikeMechanic]

Thanks for watching and your comments

[@ChristianJohnsons]

Excellent tear down! Thank you for doing this!

[@richardwalker5906]

Nice to see you back.. glad you're feeling better

[@TheYorkshireBikeMechanic]

Thank you

[@TheYorkshireBikeMechanic]

Thank yoi

[@michael_emtb]

Great video Dave, glad youre recovering well 👍🏻

[@TheYorkshireBikeMechanic]

Thanks for watching and your comments, strange thing that covid stuff

[@steve9502]

Great to see you back and well and doing videos!! I have at least one month left of good riding before the bike goes away for the winter. Any tips for storing your Emtb for a long period of time? Thx Steve

[@TheYorkshireBikeMechanic]

Hi Steve, the best thing to do is bring your battery inside and charge it to approx 50%, if it's a bosch battery and you know your dealer well ask them to prepare it for storage, we have a bosch battery conditioner that prepares them for storage.

[@jameslamb7085]

I honestly don't know what I would have done without this video, followed it step by step and managed to sort out the crank shaft bearings and the pcb. No error codes now and it's running like new. Are you going to do a video on the transfer gears sometime soon. Thanks 😊

[@TheYorkshireBikeMechanic]

Hi, Thanks for watching and your comments

[@rusty2222]

God bless you Dave, this is so helpful, you're a star pal.

[@TheYorkshireBikeMechanic]

Thank you

[@pygmalionize]

thanks for the videos, much respect from a friend in Morocco

[@TheYorkshireBikeMechanic]

Hi, Thanks for watching and your comments

[@theziggyg]

Great video,👍🏼 great you’re back on deck from covid 😊

[@TheYorkshireBikeMechanic]

Thank you

[@Scaredysquirrelmtb]

My best source of information thank you for what you do here cheers

[@TheYorkshireBikeMechanic]

Hi, Thanks for watching and your comments

[@tandembike]

Thank you! Really wanted to see what a Gen4 innards looked like and how it works. Bosch is so protective of it's dealer network (not a complaint I understand why) it's impossible outside of youtube to see what's going on inside. Outside of bearings I doubt there is anything that a consumer could fix as I don't know where/how you could source circuit boards and sensors. Stay well and hope you enjoy continued success with your recovery,

[@TheYorkshireBikeMechanic]

Hi, Thanks for watching and your comments, the only source of components are from broken or stripped down motors

[@officialmysteriousrider130]

PCB printed circuit boards

[@Aycim1990]

I betterbgave watched this before fiddeling on my motor 😅 But nothing damaged and now i know better! Thanks for your really nice videos!

[@givreycham]

Thanks Dave a brilliant video....makes brain surgery look easy! I can't imagine how you worked out how to do that and the pitfalls but very skilful.

[@TheYorkshireBikeMechanic]

Hi, Thanks for watching and your comments.

[@SingletrackScene]

Absolutley Brilliant Dave! Thanks so much for this!

[@TheYorkshireBikeMechanic]

Thank you, your welcome

[@brentgregory1359]

Brillant. Thanks Dave, another great video.

[@TheYorkshireBikeMechanic]

Thank you

[@richard73]

Glad to hear your feeling better 👍👍

[@321bytor]

you're

[@TheYorkshireBikeMechanic]

Thanks for watching and your comments, thanks

[@Nils6699]

Great video! Showed me that this is propably the only part on my bike i cant fix my self sadly.

[@TheYorkshireBikeMechanic]

Hi, Thanks for watching and your comments

[@iTCXtreme]

As always a very informative video, keep up the great work 👍 👏 👌

[@TheYorkshireBikeMechanic]

Thanks

[@iTCXtreme]

@@TheYorkshireBikeMechanic Your welcome, take care 😊 👍

[@kevinward6680]

Superb video! Well done and explained perfectly!

[@TheYorkshireBikeMechanic]

Thanks Kevin

[@TheYorkshireBikeMechanic]

Thank you

[@ninjatwentyone]

What a cracking video, very informative. Thank you👍🏻

[@TheYorkshireBikeMechanic]

Thanks for watching and your comments

[@powerbikesbg]

Thank you! Just done it thanks this tutorial! Regards from Bulgaria!

[@TheYorkshireBikeMechanic]

Hi, Thanks for watching and your comments

[@adrianhrusca4067]

After how many kilometers youbhad to service it? Thank you!

[@powerbikesbg]

@@adrianhrusca4067 The engine with the noisie bearings was only on 700 km

[@adrianhrusca4067]

@@powerbikesbg thank you! What bike?

[@powerbikesbg]

@@adrianhrusca4067 Cube Stereo 120 2021

[@Booga76]

This particular video is very useful, thanks ! :)

[@TheYorkshireBikeMechanic]

Your welcome

[@cannonballebikesltd9660]

Excellent informative video thanks for putting together. Quick question I currently have 3 gen 4 motors that are out of warranty with error code 500. Have you had any experience with this and a possible fix ? I’m a certified bosch tech myself however can’t get any help from Bosch on this other than they it’s moisture ingestion. Thanks Colin

[@TheYorkshireBikeMechanic]

Hi Colin Thanks for watching and your comments. Its a tricky position your in with these motors, Im surprised at Bosches refusal to help out, but I don't know how much out of warranty they are out by. 500 errors are nearly impossible to sort out if they return after a reset. the only way to sort them is a bosch replacement under warranty or a new motor paid.

[@mattletch6704]

Excellent video, many thanks.

[@aborsic]

Thank you for making this informative video !

[@TheYorkshireBikeMechanic]

Your welcome

[@TheYorkshireBikeMechanic]

Thanks for watching it, you are welcome

[@simonelanciarini6281]

Complimenti!!! Molto professionale!!! Sarebbe bello un altro video dove descrive la sostituzione dei cuscinetti e la lubrificazione degli ingranaggi. Attendo con pazienza.. Grazie, Simone

[@TheYorkshireBikeMechanic]

Thanks for watching and your comments

[@jeffreybail353]

great vid, well done!!

[@TheYorkshireBikeMechanic]

Thanks for watching and your comments

[@MemoMayoralMexican]

Hi, this is a great video. I have a question, is it possible for the chainring to rotate at a higher speed than the pedalling speed? What happens is that I don't quite understand the relationship of the clutch with the cranks when pedalling and receiving assistance from the electric motor. Thanks and excellent work

[@TheYorkshireBikeMechanic]

Hi, thank you for watching and your comments, sorry I am not sure what you mean.

[@Andrea-vv1ol]

Wonderful video compliments. Why don't you make another one where you show how all the bearings are changed? It would be magnificent

[@TheYorkshireBikeMechanic]

Thanks for watching and your comments, simply because it would be a too long video.

[@rafaelmerino5372]

Dear colleague, thank you very much in advance for the great work you have done for the entire community. I wanted to ask if you know what type of grease this Bosch G4 motor with metal metal gears uses..

[@TheYorkshireBikeMechanic]

Hi, there seems to be conflicting info on which grease to use at the moment, I am working on it

[@mmaaddict78]

I would guess a moly grease. Because moly grease doesn’t squish out from between gear teeth.

[@miguelgargallo2206]

Muy bien por el video, me ha servido de mucha ayuda para cuando tenga que desmontar mi motor y poder repararlo yo mismo. Gracias.

[@TheYorkshireBikeMechanic]

Hi, Thanks for watching and your comments

[@sijmes]

Great vid, do you think at some point that Bosch may make new or maybe reconditioned motors available ? Ive seen other people selling them online, salvaged from damaged bikes or so they claim.

[@TheYorkshireBikeMechanic]

I don't think that they will, Each motor is programmed for the bike and gearing thats its going in. this is done by the bike manufacturer at the time of install. I dont see how they can sell them on ebay as they will be pre-programmed

[@carstenreeder8634]

Hi Thank you for your excellent videos. Well explained and in a likeable way. I have a gen4 motor with an yet unidentified electrical internal failure. Code 550 was shown and my shop guessed it has a damage on the board from water that got inside. Now my question. I could get a motor wich is all fine but two pins of the display plug in are broken off. Do you think it might be possible to change out the connector sections between the two boards? To make the otherwise good motor be useable again with the connector section of my old motor. I am confident to be able to disassemble them like in your video and should be able to solder stuff in and out the board. But I have no idea if the section with the connector plug ins is just soldered on or for waterproofness is somehow glued too. I am german and hope this is explained in an understandable way. Kind regards, Carsten.

[@TheYorkshireBikeMechanic]

Thanks for watching and your comments, unfortunately the connector pins are so incredibly difficult to replace or straighten, it's like micro circuitry and there are no spare parts available, if it's a last resort then it might be worth a try.

[@juhavuorinen7711]

4 month ago I did replace those outer casing bearings and now I might have a problem with drive gear one way clutch bearing. Have you removed that bearing from that cogwheel? In video you say it can be done by pressing but is there any lock ring or anything that must be taken off before you press? Obviously you need to develop some kind of tools to press that bearing out without damaging the cogwheel.

[@richardkaz2336]

It's good to see that the Gen4 motor does not have plastic gears like the earlier motors. Have Bosch improved the crank seals or are just a prone to water ingress?

[@TheYorkshireBikeMechanic]

Hi, thanks for watching, they have improved but there is still away to go. Im not sure what the answer is but I cant help thinking that cars don.t suffer the same issues where the driveshafts come out of the gearbox??

[@MathiasMatzat]

What a difference to my Gen 2 motor I opened recently to put fresh grease to the gears. I don't know I would dare to open the Gen 4 motor of my new GravelBike some days in the future.

[@xmateinc]

Be nice when bosch makes these bearing kits easier to replace. Im gonna use mine for a long distance tour, and hope the bearings last.

[@richardkaz2336]

That torque sensor cable. If the solder has broken but the circuitboard tracks are in tact and all surtface mount components are intact then you should be able to load up some surface mount flux to the circuit board and and cable connector and using a fine nozzle air heat solder gun to refloat the connections. Worth a try. It is surprising that Bosch did not apply some epoxy or adhesive to better support the connection.

[@TheYorkshireBikeMechanic]

The torque sensor unit is quite sturdy and will stay in tact providing that the unit is dismantled in the right order, compared to the sensor on the shimano e8000

[@davedavies8002]

Any idea where I could find new circuit boards? My motor was soaked and had water inside, slight corrosion in places.. I've cleaned them with contact spray but I'm not convinced id rather replace them now the motors apart instead of rebuilding and stripping again

[@richardharker2775]

Very good description of how the everyday handyman will lose a lot of money trying to do things outside of their expertise. One question if I may. Would these motors benefit from some sort of regular service?

[@TheYorkshireBikeMechanic]

Hi Richard, yes leave well alone. They are virtually maintenance free apart from replacing the external the 2 protection covers on the end of the axle (on the outside)

[@thomasclement2912]

Hello, great video, thanks!! Where did you get the tool to put the freewheel back in? bought or made by yourself? Cheers Tom

[@TheYorkshireBikeMechanic]

Hi Tom, thanks for watching and your comment, I made it on the lathe

[@nickclarkuk]

Thank you for a great video ! I starting to appreciate why these things are so expensive! The technology and tolerances might put Tesla to shame .

[@TheYorkshireBikeMechanic]

Thanks for watching and your comments

[@adrianhrusca4067]

And they are made with low weight on the mind...sadly they don't last (in general, not this Bosch gen4)...

[@Bikeaddict4235]

Note to self , never ever try and dismantle one of these 😂 Another good vid dave thanks

[@TheYorkshireBikeMechanic]

Thanks 👍,

[@alfabethev2.074]

Well.. you've just convinced me, to, never ever try to disassembly my cx-motor!🥶 Tnx. 4 da vid. 👍🏻

[@TheYorkshireBikeMechanic]

Glad you decided against it, nightmare

[@urabus_]

good day, what lubricants should be filled inside the engine (calcium or lithium) and how often should it be done

[@EbikeGuadarrama]

Buen trabajo,un saludo de Paco, un compañero español

[@TheYorkshireBikeMechanic]

Thank you

[@cecilioysupena]

geniasl video, me va a ayudar, me puedes decir donde comprar la herramienta extractora del eje central con esas zarpas? sera de gran ayuda. gracias por el contenido gratuito y poder aprender contigo.

[@301jax]

Great , thanks for the great vid 🙏🥳

[@TheYorkshireBikeMechanic]

Hi, Glad to help, thanks for watching and your comments

[@rg8707]

Looking forward to work on one of these motors after this video. But now I just finished a Brose motor and my question is should i put grease on the planetary gears? I read to use a Molykote PG-75. I don’t see any body using it or if so how much. What do you think , all these motors have gears being plastic on plastic or plastic on metal.

[@TheYorkshireBikeMechanic]

Hi, Thanks for watching and your comment, the reason you dont come across pg-75 is because its so expensive, its good stuff though. Bosch make some really nice grease for nylon, its called Bosch gear grease, they also make bearing grease, really tacky, great stuff

[@MrGervasius]

Thank you for such detailed explanation in video. Is the torque sensor the same as cadence sensor. I'm getting that error and sometimes intermittent assistance.

[@TheYorkshireBikeMechanic]

Hi, Thank you for watching and your comment. No they are 2 different things, the torque sensor measures the amount of pressure you put through the pedal. When you say cadence do you mean speed sensor?, the speed sensor sits on the rear frame near the wheel. cadence measures how many revolutions on the crank per minute.

[@MrGervasius]

​@@TheYorkshireBikeMechanic I got an error code 513001 and I found the meaning to be a cadence sensor problem. Yesterday I also rode and got error 510006 which means Torque sensor does not work properly. Today everything works fine but anyway, I have to go to the service asap. I hope I will not need to replace whole motor. Your content is great. Makes me want to be a bike mechanic too.

[@ivanbayarri2807]

Glad you are doing well. So my Bosch moter with the horrible rsttling noise going over rough terrain is going into warrenty hope they can solve the noise is horrible

[@TheYorkshireBikeMechanic]

Let me know how you get on.

[@user-zp5zz4qy2d]

Realy a nice video with all important hints to face the challange. Thanks for that! I am out of warranty with my engine and it makes terrible noises. So my idea is to removal the bearings. I have questions: 1. The tourqe sensor was loose in your video because of failed first trial is that right? 2. Did you have videos available describing more detailed how the removal of the bearings works? It would be nice to here from you Thomas Kück

[@TheYorkshireBikeMechanic]

Hi Thomas thank you for watching. The torque sensor was damaged by the previous owner, he tried to replace the bearings himself with no knowledge, I got the motor to carry out experiments etc. The video was made as a reference guide only to show how difficult it is to do, one wrong slip and your motor is rendered useless. I would not recommend you attempt it unless it’s a last resort.

[@user-zp5zz4qy2d]

@@TheYorkshireBikeMechanic I have most of the parts and bearings apart because I found rust inside the transfer gear. At the end of your video you mentioned an additional existing video of bearing change and transfer bearing special. Can you provide a link of this video please or even a couple of information descriped in text?

[@huntjk1]

Hi there again just a quick question should the gears (cogs) inside gen 4 have grease on them if so which grease thanks again

[@TheYorkshireBikeMechanic]

Hi, Thanks for watching and your comments. yes they should but not too much, Bosch have done away with nylon cogs in the gen 4 so the grease choices are more, my personal choice would be MOLYKOTE PG-75

[@Paulo-fr3xm]

Glad you're feeling better Dave, on the motor, if it's out of warranty and you develop an issue, can you get these motors refurbished or repaired? And if so where.

[@TheYorkshireBikeMechanic]

Hi, thanks for watching, if the motor is too old to be covered un out of warranty bosch sell refirb kits for us to repair them. If its beyond repair then we will supply you with a new one, unfortunately at RRP price

[@alasdairhill5166]

Hiya yes a company in UK called performance line bearings 👍

[@Extremegaz25]

Howdo dave, hope your free of the convic's, and great video.

[@TheYorkshireBikeMechanic]

Negative, back now to being a full idiot as normal

[@geistbike]

This is a very interresting video with many detailinformations.....excellent ........Greeting from Germany

[@TheYorkshireBikeMechanic]

Thanks you

[@VovanCBR]

thank you, it would be interesting to see latest version of this motor with wireless speed-sensor (latest generation from smart system with RIM magnet version). and compare to wire speed sensor version.

[@TheYorkshireBikeMechanic]

Hi, yes it would, they are still very new and so I cant get hold of one, I would expect the internals to be nearly identical, its the electronics thats would be different.

[@VovanCBR]

@@TheYorkshireBikeMechanic why would they need so many identical motors, why not to stick to one model, if you introduce a new one, make at least some torque or speed improvement

[@vincenzomustica2045]

Good morning excellent video it is the only one that exists on the net of this 4th generation engine, the problem with my engine is that I have to extract the one-way bearing from the sprocket, can you tell me the procedure for extracting the one-way bearing? Thank you

[@TheYorkshireBikeMechanic]

Hi, thank you for watching and your comments. sorry but it would take me ages to write it all down, sorry

[@crashedagain]

Very informative video but getting Bosch parts is very difficult. I have tried to get a bearing kit from tow Orbea dealers to no avail. They don't seem to be getting a response from Bosch about a bearing and seal kit and a torque sensor which I broke when a tool fell off the shelf above my bench. I now have a bike that has been down for a month and I am very frustrated especially since the bike has less than 50 hours and has been well cared for. Any recommendations on how to get parts for the Gen 4 motor?

[@TheYorkshireBikeMechanic]

Hi thanks for watching, there are no official parts available for any Bosch motor, only option is try performance line bearings he could have some used parts available

[@christianhirtler8682]

Hi... Thanks for the very good video. I have one question: Are there any issues if you open the motor and want to connect it again. I heard some stories about other e-bike motors that they do not work anymore after opening the cover since they have a "safety switch off" implemented in the software.

[@TheYorkshireBikeMechanic]

Hi, there is no anti tamper device that will stop the motor working when the cover is replaced or removed on any motor.

[@christianhirtler8682]

@@TheYorkshireBikeMechanic Thanks for the quick response!

[@steve9502]

Hey Dave. Quick question, I’m changing the cassette, chain and chainring on my Shimano e8000 Commencal. I want to go from 34t to 32t chainring, is there any issues I should know about. Thx Steve

[@TheYorkshireBikeMechanic]

Hi, it’s difficult to comment because the motor will have been programmed for the original chainring, it could generate an error message, only way to find out is try it

[@stephenbrown5844]

Hi dave, pleased your OK and slowly getting over your covid🤬🤬hate the dam virus🫠Thank you so much for your info on my bosch gen4,,, I think when it's needed I'll give you the job bro😁👍excellent info yet again 😝❤️🇬🇧🇬🇧👌stay well 💚💚

[@TheYorkshireBikeMechanic]

Thanks Stephen

[@rg8707]

Great video , what tipe of grease is used in these motors ? will you do a video on a Brose motor

[@TheYorkshireBikeMechanic]

Hi, thanks for watching, Bosch as far as I am aware don't specify an internal grease, I would probably say a low temp moly based grease

[@TheYorkshireBikeMechanic]

Might do brose soon

[@wentai3162]

thanks for your vidéo, however do you have a vidéo about put or remove motor from bike ?

[@TheYorkshireBikeMechanic]

Hi, yes I do but not the gen4

[@nvmcrider8475]

Great design on your puller, ever had a frame get pulled apart?

[@TheYorkshireBikeMechanic]

Hi, no never

[@kepakko0]

Great video! Thank you! I’m just curious to know the ”tool” pipe diameters 25:15 , as iam going to make bearing replacement myself. Is it some standard pipe or some machined piece ?

[@TheYorkshireBikeMechanic]

Hi, Thank you for watching and your comments, if I remember it is 19mm internal and 32 external,

[@michaeldiederich9434]

​@@TheYorkshireBikeMechanicihink the Size ist 19mm inner and 22mm outer diameter

[@yali1408]

Hi. I’m stuck now. Did everything and putting it back together and now there’s a tool I need to make to get the drive bearing on! How do I make this tool. What do I need? What’s everyone else done ?

[@CushtyHealthFoods]

What’s the diameter of the piece of tube you used to put the one way bearing back on oh yeah what size are them bolts to bring up the main motor carefully and straight.

[@TheYorkshireBikeMechanic]

I will dig it out and check for you

[@frankedoodle3798]

Hi do you know if there is a noise when the crank is moved backwards and forwards a tiny bit - It’s not a rattle, more a slight sound as you go from freewheeling to engaging the motor. If you ride along freewheeling then very slightly peddle to engage the motor, there is a slight clunk as it engages.

[@TheYorkshireBikeMechanic]

Hi, thanks for watching and your question. each brand of ebike motor has its own characteristics, some will be fairly quiet during use, others can be clunky during transition from power to overrun. they all generate different noises that are normal for that particular motor. unfortunately it's experience and diagnostics that tell us when something isn't right. if you have a good ebike mechanic let them have a listen and ride or if you have a friend with a bike with the same motor compare it with theres.

[@thurgogopro5338]

So where the splined shaft goes through the motor casing am i right in saying there is no oil seal to round shaft seal (like a petrol engine crank) due to the splines, if so no wonder they fail

[@TheYorkshireBikeMechanic]

Just a simple rubber oring

[@TheOffroader7458]

Looks pretty simple to be honest, being a motor technician repairing semi automatic transmissions and modern engines. Good video by the way

[@TheYorkshireBikeMechanic]

Thank you

[@gazmaccmilk]

I am a lego technician. Surely fixing transmissions and stuff should be just as easy

[@TheOffroader7458]

@G Mac l take it your still a child?

[@kjeldschouten-lebbing6260]

It's incredible how many basic design flaws and cornercutting is in this thing. No wonder Bosch is so protective about it.

[@TheYorkshireBikeMechanic]

Hi, thanks for watching and your comments

[@serious-rc933]

Thank you verry much, wanted to see how it looks inside, so now i dont need to open it up.

[@TheYorkshireBikeMechanic]

Thanks for watching and your comment

[@johnwinters6999]

Brilliant motor

[@CushtyHealthFoods]

Hi my name Stephen what a great video. Ok I think I have a major problem with my gen 4 it got contaminated with water I dried the connections that plug into the side of the motor but the bad thing I’ve done is the pins that actually are on the board I bent one and broke another will this now mean a complete new electrical board if I took it to a dealer would probably cost the price of a new motor I wish I never put a screwdriver inside where the pins are I believe it maybe’s need a new pcb board 😢do you know where I can get one and then the motor will have to be stripped down which is why I watched your video.

[@TheYorkshireBikeMechanic]

Hi Stephen, sorry to here about your motor issues. The likely hood is that I will need a new board. As a dealer I would probably quote you for a new motor i'm afraid. There is one person that may be able to help and it's worth a try, it depends on if you are in the uk. give Peter a call from Performance line bearings, tell him what your issue is, it's worth a call.

[@CushtyHealthFoods]

@@TheYorkshireBikeMechanic I will give him a call maybe can help.

[@oskarmaziak2542]

It’s interesting gear box to use 🤟💪👍😎

[@TheYorkshireBikeMechanic]

Hi, Thanks for watching and your comments

[@thomasg.3377]

What's the exact bit needed to open the carter's screws? Looks like Torx Tamper 27?

[@TheYorkshireBikeMechanic]

Hi Thomas, Not sure about the carter screws but moster of them are torx plus

[@giovanni1717]

Hi! My motor has stopped clicking when backpedaling. Everything works but backpedaling will bring the chain backwards like a non emtb. Should i be worried? Could it just be the spring for the ratchet that is stuck? It will click if i force it while holding the chainring still, and also when i stop pedaling and it overbosts.

[@TheYorkshireBikeMechanic]

Hi, Thanks for watching, This is not normal, you need to get your motor checked as soon as possible

[@totoxahc]

Is it really a torque sensor? How could it measure torque without anything being attached to the shaft? I though there would be a strain gauge. Also I know that motor controllers can estimate torque without any sensor on the motor itself

[@TheYorkshireBikeMechanic]

Hi, thanks for watching and your comments, complicated electronics, magnets

[@marius8349]

Hello, what about a Bosch Gen 3, is there any important precaution in removing the cap, or is it like Gen2? Thank you

[@TheYorkshireBikeMechanic]

Hi, thanks for watching and your comments, gen 3s are a bit different but I've never filmed one, next time I will

[@marius8349]

@@TheYorkshireBikeMechanic Hi, thanks for reply, that will be a good thing to do, there isn't even one about a Gen3 motor and I've seen lots asking about. All the best.

[@thurgogopro5338]

At 4.48 you said remember this circlip, i dont recall seing it come off in fact you told us to leave the 2 shaft circlips on earlier, im confused

[@TheYorkshireBikeMechanic]

Hi, sorry for the confusion, originally there was one circlip on the shaft, I removed it earlier, I put it back on and another one on top.

[@tonomontero925]

It would be good to have a video on what parts of the engine to grease, how to grease and with what?

[@TheYorkshireBikeMechanic]

Hi, I have stopped overhauling motors due to their complexity

[@tonomontero925]

😢

[@niccots]

The circuit board is just like that with wearing material and lubricants?

[@TheYorkshireBikeMechanic]

Hi, thanks for watching and your comments, yes

[@DJDOG-zakkgamer6423]

Why don’t you chop the heads off the long / locating bolts ? For locating the magnetic part. Then it won’t be as awkward holding it with one hand and screwing the bolts in / out when assembling / disassembling , just a thought 👍

[@TheYorkshireBikeMechanic]

Hi, thanks for watching and your comment. great point, thank you

[@edwinalfredoconchacastro9128]

Hello friend, I need the tool to install the gear with internal bearing. Is it the manufacturer or is it sold by the Bosch brand?😅😊

[@TheYorkshireBikeMechanic]

Hi, thanks for watching and your comment, home made

[@su1raM]

Could you please share inner and outter diameters in mm of drive cog installation tool? That I can make it/buy or cut before dissasembling the engine. Thanks

[@TheYorkshireBikeMechanic]

Hi, sorry but I have given the tool to a customer, I only made one and unsure of the dimensions to be sure.

[@thomasmoran1799]

Hi Dave in your opinion witch motor is best for ebike????

[@TheYorkshireBikeMechanic]

Hi, thank you for watching and your comments, such a good question, I would say, Brose

[@dankhalifa6937]

Hello what can be the problem when im spining pedals they spining inside the motor but the chain barley moving, i can send you video if possible

[@TheYorkshireBikeMechanic]

Hi, thanks for watching and your comments, yes please send a video, [e-mail]

[@groochas1]

Do you have any idea how to minimise rattle noise on descends? Put some grease on a ratchet maybe?

[@TheYorkshireBikeMechanic]

Hi, thanks for watching and your comments, check it out to see where its coming from

[@groochas1]

​@@TheYorkshireBikeMechanic it is from constantly enganging and disengaging ratchet (20:03min)

[@streamg]

How much would you charge to change all the bearings on gen4? In my country they want 500€ but that seems too much cause new motor is 699€. Tnx

[@TheYorkshireBikeMechanic]

Hi, Thanks for watching and your comments, its not a service we provide

[@gazmaccmilk]

I have the moisture fault. Can the board be dried out and work again. Thanks

[@TheYorkshireBikeMechanic]

Hi, If its under 3 years old ask your bosch dealer to speak to bosch about it