Bosch Chainring - How To Properly Change An Ebike Sprocket Bosch Gen 2 BDU250C / 255C Series

This video covers the proper ways on how to replace a Bosch Chainring on a Bosch ebike mid drive motor system. Will takes you through the proper steps on how to properly change out these chainrings using the proper tools and techniques.

If you have any questions about this video please feel free to ask us anything and we'll do our best to answer them. Have a topic that you would like us to talk about? Let us know we would love to hear from you!

When changing out a Bosch chainring using the proper tools is essential in completing the job correctly as shown in the video. Here is the list:

TOOLS:

- Allen Key / Hex Key 8mm

- Small Pick / Toothpick

- Torque Wrench

- Bosch Service Tool Kit Bundle:

PARTS:

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[alexsabolta]

Started out using this video to change my chainring on my 2019 trek dual sport +. Got caught out on the bni - gen 3 spindle. All sorted in the end.

[spessartknorz]

Just watched the video and for the first time I could actually follow instructions, you made it very clear, the best part was you were slow enough so we (read I) could also follow those instructions, well done you have me hooked.

[DGwhitehawk]

I had to change crankarms on my ebike and this video got me throught it with ease. Thank you so much for this awesome tutorial!

[wakeywarrior]

Worth pointing out the 3mm spacer is sometimes built into the chainring so if there is a 3mm ridge on the back of the chainring, and your new one doesn’t have that built in offset then you need a spacer. For example, the Sram Eagle versions come flat but with a spacer for boost in the bag.

[genoafire]

Great video thank you. Very professional and detailed. You could easily make a living teaching others on how to make an instructional video.

[mike_oe]

1:30 thank you for pointing that out!!!

[HP-jdmt]

A sprocket remover / chain whip is to be used in order to hold the sprocket in place while removing and fastening the lock ring. Also to be mentioned that most of the torque wrenches do not work anti-clockwise, regardless to the presence of the switch to rotate ratcheting direction.

[infernokush]

Can we change the chainring to a bigger one or would I have to get a software upgrade

[Cheradanine]

Great video, very informative.
I played a drinking game and took a shot at every "go ahead". Was pissed before the video end....

[riteandleft]

Truly excellent video and first class, unambiguous instructions. Thanks.

[michielnoback]

Op 11:40 zit z'n broek vol! Linksom klikt z'n momentsleuteltje niet 🤨 Voor de rest van de video: TOP💪

[SoundsandSightsVideos]

Great video. For the Park Tool. Is it the CCP-22 or CCP-44 for Bosch Gen 4 Crank Removal tool, please?

[QuadPawCreations]

Great video! I have a Trek Crossrip+ and need to change out the 20T chainring. I have a Park crank arm extractor tool but the crankset is hollow and there is nothing for the tool to push on. What does the tool you used push on? I need to purchase the 20T chainring and the locking tool. I don't see the links to purchase them from.

[normhapp]

I have a Fuji E Transverse One.3 with the Bosch motor in the sprocket. The Bike has 5600 miles. It is only used for road or a paved path. Yesterday the chain jumped the front sprocket and became very tightly wedged. I checked the chain wear with a Park CC-1 chain checker. The wear is in the blue (good) zone. Since there is no front derailleur, I am at a loss as to what would make it jump the front sprocket. The sprocket teeth do not appear to be worn. I plan to change the chain, but I am not sure that this it the cause of the problem. Any advice would be greatly appreciated. Norm

[VonPonzen]

Great video! Very detailed.
Could you replace the sproket with a bigger one with more teeth?

[dbok]

What’s the name of the thing the chain ring slots onto and does anyone know if you can get replacements as mine has the threads torn up nearly flat from the past owner

[denesk]

Important warning: some torque wrenches only click clock-wise!

Put your wrench into a MUCH LOWER torque setting and see if it clicks. Else you will need a long extender and reverse the torque action with an open wrench attachment.

[peterlord]

Great Video with just the right level of detail. However my Bike uses a spider with a larger chain ring can you please do a video for this setup.

[chuckkoehler]

I want to install an 80T #40 1-inch bore size sprocket on my e-bike. It has a Prowheel 52T #40 sprocket on it right now. Are there any issues or concerns doing this? Can I just buy a type A sprocket with extra chain links or #40 chain. It would be nice to also have a sprocket guard also.

[genniz]

150$ shipping for 5 bosch orings to Norway thats insane! btw great video! :)