Bosch CX Gen 4 Mileage/Reliability

Spanner Monkey

Spanner Monkey

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Hi All Im interested to find out what sort of mileage people have racked up on gen 4 motors and what if any issues they have encountered along the way.
Ill start then, I have covered 1100 miles so far in all sorts of mud and rain mostly off-road. I have had a 510 code at around 500 miles which cleared just by switching the bike off for a minute and once it just turned itself off with no code, turned it back on without even stopping and no problems since.
 
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700 miles in and I've currently got no motor assistance, just cut out mid ride. Some more details here if anyone has any suggestions....
www.emtbforums.com

Motor assistance cut out mid ride - gen 4

Hi all, I've got a new issue and looking for advice if anyone can help. 3 miles into my snowy ride today the motor assistance cut out. My kiox display is still on but it shows a dash in the battery icon instead of a battery %, this is what you see if the battery isn't in the frame, so it's not...
www.emtbforums.com www.emtbforums.com
?
 
500 miles so far and the motor has been fine, but the kiox display failed at around 300 miles. It was quickly sorted under warranty, so not a big deal.

I think some water got into it through the USB port cover, I've now got it taped up with electrical tape, and I remove the kiox when I wash the bike.
 
1500ish miles in the best and worst that the UK can throw at a bike. False 504 (tuning) error near the beginning, nothing since.

I was on my third Gen 2 motor by then...
 
2 2018/19 models GEN3 used and gone , and replaced for 2 models GEN4 2020/21. All with more than 1500/2000Km. No motor issues so far. Only to report 1 Kiox display went crazy and replaced under warranty.
 
405 miles since July 2020 all off road (no trail centres) just developed a pedal pressure to motor engage delay, the pedal crank moves 25mm or so before assistance kicks in. This occurs on every gear in all assistance modes on the Purion. LBS to investigate so watch this space ?☹️
 
The EMF said:
405 miles since July 2020 all off road (no trail centres) just developed a pedal pressure to motor engage delay, the pedal crank moves 25mm or so before assistance kicks in. This occurs on every gear in all assistance modes on the Purion. LBS to investigate so watch this space ?☹
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Problem with freewheel hub now sorted ??
 
Steve940 said:
What was the problem ?
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Long story short, I had to have hub bearings replaced by my LBS , this problem occurred during first ride after the repair, bit of a coincidence The freewheel assembly removed and cleaned, all excess grease removed and re-lubed by the LBS. The motor take up appears to be ok now when I’ve pedalled up and down the back lane but not tried it in anger. I’m a little sceptical but the mechanic assured me that the pauls in the freehub ass were not engaging as they should. Will just have to see how this pans out. The motor is quiet through the gears and in all assistance modes........would be good to hear if any other members have had this problem with Whyte hubs.
 
The EMF said:
Long story short, I had to have hub bearings replaced by my LBS , this problem occurred during first ride after the repair, bit of a coincidence The freewheel assembly removed and cleaned, all excess grease removed and re-lubed by the LBS. The motor take up appears to be ok now when I’ve pedalled up and down the back lane but not tried it in anger. I’m a little sceptical but the mechanic assured me that the pauls in the freehub ass were not engaging as they should. Will just have to see how this pans out. The motor is quiet through the gears and in all assistance modes........would be good to hear if any other members have had this problem with Whyte hubs.
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This could occurred by the mechanic being a bit overzealous with the grease after the bearing removal but the bearings are sealed so would there be any excess grease ? I’m a retired maintenance engineer hence the scepticism of the LBS.
 
The freehub still needs grease in it
The EMF said:
This could occurred by the mechanic being a bit overzealous with the grease after the bearing removal but the bearings are sealed so would there be any excess grease ? I’m a retired maintenance engineer hence the scepticism of the LBS.
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The bearings dont need grease applying , but the freehub still needs grease in it, so I reckon your theory about the LBS putting too much grease (or maybe too thick grease) in it is a sound one.
 
Mteam said:
The freehub still needs grease in it

The bearings dont need grease applying , but the freehub still needs grease in it, so I reckon your theory about the LBS putting too much grease (or maybe too thick grease) in it is a sound one.
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I hope so because I want to have trust and faith in my LBS after all it’s where you go for warranty work. When you do 99% of work on your own bikes you pay attention to detail. The LBS probably don’t have time for ,that degree of attention, it’s a business after all.
 
I've had a couple of issues with what I thought was a speed sensor, as the motor would cut out occasionally, and the speed would be zero, so had my LBS order a new one. It's only about £25.

Upon fitting, there was a lot of mud and crap around the motor, so he's cleaned it all out, fitted the new sensor anyway, and it works perfectly. Tbh, I'll hold my hands up and admit user error, as I didn't think that much mud could get in there, but it was really clogged up. So, make sure you periodically clean your motors, folks!
 
RichT001 said:
I've had a couple of issues with what I thought was a speed sensor, as the motor would cut out occasionally, and the speed would be zero, so had my LBS order a new one. It's only about £25.

Upon fitting, there was a lot of mud and crap around the motor, so he's cleaned it all out, fitted the new sensor anyway, and it works perfectly. Tbh, I'll hold my hands up and admit user error, as I didn't think that much mud could get in there, but it was really clogged up. So, make sure you periodically clean your motors, folks!
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Was this done under warranty?
I take off my bash guard every 5/6 rides in the winter and it’s always full of mud/crap. Well worth doing for the few minutes it takes.
 
Spanner Monkey said:
Was this done under warranty?
I take off my bash guard every 5/6 rides in the winter and it’s always full of mud/crap. Well worth doing for the few minutes it takes.
Click to expand...

Nope, I paid for it, as it was my fault. It probably didn’t need changing tbh, but I wanted all bases covered while It was in the shop.
 
²
RichT001 said:
I've had a couple of issues with what I thought was a speed sensor, as the motor would cut out occasionally, and the speed would be zero, so had my LBS order a new one. It's only about £25.

Upon fitting, there was a lot of mud and crap around the motor, so he's cleaned it all out, fitted the new sensor anyway, and it works perfectly. Tbh, I'll hold my hands up and admit user error, as I didn't think that much mud could get in there, but it was really clogged up. So, make sure you periodically clean your motors, folks!
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Is that just simply removing the main cover ?? Sorry I've never touched an ebike so to speak lol
 
RichT001 said:
I think so. I’ll check when I speak to him next week.
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Im guessing it must be just the cover as the motor is warranty sealed so even the bike shops don’t open them up, they just replace the whole unit if it ever fails.
They only get repaired once the warranty has expired currently no one repairs gen 4 as they are all too new to be out of warranty.
 
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