"2nd dead bosch gen 4 motor not happy

Evelhornet

Member
Feb 13, 2023
29
25
Wales
If Cube and other bang for buck manufacturers would make a bafang bike many people would prefer it.
What kind of sorcery is this! šŸ«£
I'd like to see what it looks like inside next (after a few more weeks of dip testing) Not that I'm sceptical or anythingšŸ¤”
 

Gareth

Member
Apr 20, 2024
111
139
Ayrshire
the answer to my question to Bosch or my bike is also for home/work traffic...because in the Netherlands it still rains every day:oops:



Rutger, We're sorry to hear about your problems. However, this problem does not occur often and Bosch does use a rubber ring on the bearing to seal the shaft. Our components are splash-proof and therefore not intended for driving in heavy rain. We recommend that you have your ebike regularly serviced and checked for possible missing seals. then these problems will no longer occur as long as the eBike is used responsibly, of course. We will have to refer you to your nearest Bosch dealer. This can help you with this.. Here you will find the link to your nearest Bosch dealer: EN: Een dealer zoeken - eBike-informatie, advies en proefritten zoeken BE: Een dealer zoeken ā€“ eBike-informatie en proefritten zoeken We wish you a very nice day! If you have any further questions, we are always here to help. Kind regards, Daniel Vanackere Your Bosch eBike Team



I'm going to send Bosch mail number 3 now:giggle:

Is that an official response from Bosch? Splash proof, and not intended for use in the rain?

FFS!
 

Bearing Man

Ebike Motor Centre
Patreon
Sep 29, 2018
976
2,332
UK
@Bearing Man Is it possible to oil fill EMTB motors at service? Would it work?
It would definitely help! But not possible on motors that are not currently designed for it.
Worth a watch.

Is part of the solution oil filled e motors?

This is a great video, but missed the real reason motors fail. Putting aside pressure washers etc.

As we all know, you can ride your emtb through deep water and nothing happens, it will appear to be fine! Unfortunately, the failure will often occur months later when you have completely forgotten about the dunking you gave it 6 months ago. It will be a complete mystery why this happened!
The reason for this; with a motor in good condition, water will usually just enter into the outer bearings and not the motor at first. (Sadly, no one checked for this in the video). The bearing is still quite well sealed at this point so the water can't get out again. This starts slowly corroding the bearing race and ball bearings, this wears the ball bearings down until the bearing seals can no longer fit properly, allowing water to flood into the motor itself and eventually kill it!
 

Bob88

Member
Jul 29, 2022
78
65
Hampshire
Best way to deal with bosch CX motor issues is to ride them however you like... And then when it breaks, send it to @Bearing Man to switch out the motor for a new one! Always worked well for me! I moved up north last year but when this current motor dies, I'll go all the way to Hampshire just to get Peter to change the motor without a second thought. Service second to none.
 

RustyMTB

E*POWAH Elite World Champion
Jul 22, 2020
2,853
6,894
UK
What does the Crankshaft and sprocket carrier upgrade involve, Pete? Just curious is all. šŸ‘
 

Bearing Man

Ebike Motor Centre
Patreon
Sep 29, 2018
976
2,332
UK
Quick question:
Does anyone here have a relatively loud motor whine when they get to the 15.5mph cut out?
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,577
5,048
Coquitlam, BC
I donā€™t think thereā€™s a silver-bullet that would prevent our motors from failing. The combination(s) of abuse's are endless. Most motor manufacturers have done almost everything they can think of to prevent motor failure. We are essentially the test-monkeys for future motor development on ebikes.

Iā€™d like to stretch the longevity of my motor forever ā€¦but thatā€™s unlikely to happen. But there are a few things I can do to help (specifically regarding the Bosch CX Gen4 and probably most ebike motors).

I donā€™t power wash my bike.
I donā€™t use detergents or cleaners on my bike.
I try to maintain proper cadence.
I service or replenish the external oils or grease on bearings or seals on most moving parts.
I try to maintain stuff.
I rely on expertise e from Pete or some reviews from Jonesy (or whoever), and some of my own experiences.

And my environment differs from yours. (Heat, cold, debris, mud, water, dust, use or abuse ā€¦etc. Thereā€™s a list of things to consider.

I donā€™t think oil-filled motors are the absolute answer. Thereā€™s a number of issues that can arise from that type of motor. Iā€™ll still be searching for that silver bullet ā€¦but in the meantime šŸ¤·ā€ā™‚ļø, the market and manufacturing will evolve.
 

RustyMTB

E*POWAH Elite World Champion
Jul 22, 2020
2,853
6,894
UK
I have wondered about fitting them above the bb area I.e. between the junction of the seat & downtube & linking a standard crank/bb set up somehow. This would look stupid, add weight, weaken the frame & raise the CoG & generally not work but would lift them away from the ground. I'm available (unsurprisingly) for consultation work.
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,577
5,048
Coquitlam, BC
I have wondered about fitting them above the bb area I.e. between the junction of the seat & downtube & linking a standard crank/bb set up somehow. This would look stupid, add weight, weaken the frame & raise the CoG & generally not work but would lift them away from the ground. I'm available (unsurprisingly) for consultation work.
ā€¦and a third wheel ā€¦you know ā€¦just incase. šŸ¤”. Iā€™m also available for consultation. šŸ‘šŸ»
 

AF1

Member
Jan 12, 2021
89
62
UK
It would definitely help! But not possible on motors that are not currently designed for it.

This is a great video, but missed the real reason motors fail. Putting aside pressure washers etc.

As we all know, you can ride your emtb through deep water and nothing happens, it will appear to be fine! Unfortunately, the failure will often occur months later when you have completely forgotten about the dunking you gave it 6 months ago. It will be a complete mystery why this happened!
The reason for this; with a motor in good condition, water will usually just enter into the outer bearings and not the motor at first. (Sadly, no one checked for this in the video). The bearing is still quite well sealed at this point so the water can't get out again. This starts slowly corroding the bearing race and ball bearings, this wears the ball bearings down until the bearing seals can no longer fit properly, allowing water to flood into the motor itself and eventually kill it!
"This starts slowly corroding the bearing race and ball bearings, this wears the ball bearings down until the bearing seals can no longer fit properly, allowing water to flood into the motor itself and eventually kill it!"

Would SS Bearings help or are they too soft to last?
 

Spiff

Active member
Feb 27, 2019
449
264
Earth
@Bearing Man Yes, or Ceramic as I mentioned a while back on this thread.
One clear disadvantage of full ceramic bearings is that they cannot handle the same loads as their steel counterparts.

Ceramic bearings have lower toughness, making them more prone to fracture or damage under extreme loads and impacts.
 

Bearing Man

Ebike Motor Centre
Patreon
Sep 29, 2018
976
2,332
UK
Oh ok. In that case, do I get a refund? Because it's on my bill šŸ˜‚
šŸ˜‚ Don't worry, you have all the good stuff in your motor šŸ˜Ž
"This starts slowly corroding the bearing race and ball bearings, this wears the ball bearings down until the bearing seals can no longer fit properly, allowing water to flood into the motor itself and eventually kill it!"

Would SS Bearings help or are they too soft to last?
With SS bearings it's more a case of finding them in the right size, with the right seals, at the right price! It's just not possible.
@Bearing Man Yes, or Ceramic as I mentioned a while back on this thread.
For the reasons @Spiff stated above, but also with ceramic bearings, there are very few sizes made and even fewer with seals. Ceramic bearings are not a fan of dirt and grit either.
Many manufacturers use their own bespoke bearing sizes and getting small quantities of ceramic bearings manufactured would not be economically possible.
 

RustyMTB

E*POWAH Elite World Champion
Jul 22, 2020
2,853
6,894
UK
I recently changed the front wheel bearings on my normy Lapierre Zesty, not seen it before but they were marked LLU. I looked them up & it denotes a bearing with a sealing lip on one side for higher sealing & intended for use where one side of the bearing is exposed to the environment. My takeaway from that is designers do what they can to prolong components but in the end, mechanical components invariably wear.

Any excuse to shoehorn a photo of this beast in.

rfIfRcqa.jpg
 
Last edited:

Bearing Man

Ebike Motor Centre
Patreon
Sep 29, 2018
976
2,332
UK
The wait is over! A more comprehensive explanation, reasoning and price will be on our website as soon as I have time. I cannot confirm a price on here as prices change, but in the UK this should be just under Ā£200.00 Please note, the parts are not that expensive, but this motor is extremely time consuming.
Slide1.JPG
Slide2.JPG
Slide3.JPG
Slide4.JPG
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,577
5,048
Coquitlam, BC
The wait is over! A more comprehensive explanation, reasoning and price will be on our website as soon as I have time. I cannot confirm a price on here as prices change, but in the UK this should be just under Ā£200.00 Please note, the parts are not that expensive, but this motor is extremely time consuming.
View attachment 144527 View attachment 144528 View attachment 144529 View attachment 144530
Besides all the other upgraded parts, it looks to me that the ā€œsingle lip rotary sealā€ is one of the best solutions.

I now have 2 Bosch CX gen 4 motor sitting on my shelf and one in my bike, that will eventually fail. I feel like I can start becoming a submarine pilot again without the anxiety. (Within reason).

Iā€™ll have to figure out the logistics of shipping a motor across the pond. šŸ¤”
 

Zimmerframe

MUPPET
Subscriber
Jun 12, 2019
14,028
20,818
Brittany, France
Besides all the other upgraded parts, it looks to me that the ā€œsingle lip rotary sealā€ is one of the best solutions.

I now have 2 Bosch CX gen 4 motor sitting on my shelf and one in my bike, that will eventually fail. I feel like I can start becoming a submarine pilot again without the anxiety. (Within reason).

Iā€™ll have to figure out the logistics of shipping a motor across the pond. šŸ¤”
It's already been wet, just duct tape it to a polystyrene raft ...

(Ps I think they have us/can agents)
 

EMTB Forums

Since 2018

The World's largest electric mountain bike community.

555K
Messages
28,072
Members
Join Our Community

Latest articles


Top