Cheeb issues :-(

[Hagbard]

Hi all,

I recently bought a secondhand cheeb with an M600 motor. Everything was great, took it for my first ride on Sunday and had a total blast, though the weight is going to take some getting used to. Got home, bike covered in mud and battery nearly flat.

So washed the bike (with a gentle hosepipe), charged the battery and took the opportunity to move the display a little, which necessitated unplugging the two cables that go into the back of the display.

Once the battery was charged, turned the bike on and I'm greeted with 3 odd things:

1) A ticking noise from (I think) the motor area.
2) The display showing spurious battery readings. First 60%, then 0%, then 10%, then powering off.
3) The bike pretty much not working.

If I try to ride the bike, then when the motor kicks in it feels kind of 'grungy'.

I've taken the battery out and checked the contacts are dry, I've also pushed the connectors into the display as hard as I can, as I've read that often this is the cause of such issues.

Kind of panicking here!

Any ideas?

 

[Zimmerframe]

which necessitated unplugging the two cables that go into the back of the display.

I think in the past a few people have had issues because these cables have not been pushed in hard enough.

 

[Dengfu]

I think in the past a few people have had issues because these cables have not been pushed in hard enough.

True. Although I think the display simply won't power up or display anything when the cable is not in far enough.

 

[Hagbard]

Unfortunately that's the one thing that I'm confident is ok. Trust me, those cables are pushed in very firmly!

I've started the process of stripping the bike down to check everything is where it should be, hopefully this locates something awry.

 

[furk]

Hey there! Signed up to reply to this

I had the exact same issue, here are the symptoms I had:

^ power skipping

^ erratic battery

^ battery clicking

It ended up being a water / condensation problem in a combination of two places. There was water in the power isolation switch at the top of the downtube and at the battery connection to the motor. I think the isolation switch is the main cause of the shorting. The holes can be open at the front of the housing which allows water to easily get in. It's also difficult to dry because it's in an enclosed space. I also found the motor terminals are very susceptible to water ingress so using some decent waterproof grease has all but resolved this unless you hit it really hard with a hose.

It was a case of taking out the battery, leaving it out with the battery door off and letting it all dry out. I hit the terminals with a hair dryer to speed the process.

Hope this helps. Let me know what fixed yours, I've seen this a few times now so I'm building up a bit of a repository.

 

[Hagbard]

Hey there! Signed up to reply to this

I think I might actually love you.

Your videos show EXACTLY how my bike is behaving!

I've already inspected the power terminals at the bottom of the battery, but didn't think about the isolation switch. I'll attempt to pull that out today and take a look.

I did bring the bike inside last night to sit next to a radiator and possibly dry out, so maybe that alone will have worked.

Thank you so, so much.

 

[furk]

Haha, no worries!

Getting access to that area is pretty easy, you simply remove a couple of screws above where the battery goes (where the lock is for the battery) and that top piece slides out. From there, you can visually inspect the top of the downtube which is where I saw water.

I'd say it's a fairly important place to keep water out of because if it's pre-built (like mine is) then the Bafang wiring loom is up there with all the connections along with the isolation switch. This is where I think where replugging in the cables into the display might come from. Simply manipulating those cables might be enough to dry the water in that area. I've plugged up the additional holes where the wiring goes from the handlebars into the frame.

I've been tempted to just remove the isolation switch and solder it permanently on because as far as I'm concerned the software switch is good for 99% of the time and the other 1% of the time I'll just remove the battery anyway.

Let me know if it helps drying out that area! It sucks when something goes wrong, especially when it's not a Trek or a Giant because with those you'd just chuck em back at the shop but it's rewarding once it's going perfectly. Such a nice bike, I love it.

 

[Hagbard]

Praise be to James Dyson for his incredibly powerful hairdryers.*

I believe @furk was absolutely on the money; the area above the battery where the isolation switch is located must have had some lingering moisture in it, as blasting that area with Dyson's finest appears to have resolved the issue.

I shall sleep soundly tonight!

Thank you @furk I am in your debt.

*though his opinions on Europe and Boris Johnson remain deplorable,

 

[furk]

Woohoo! Glad to hear it!

 

[westyB]

Hi there,

Had the same problems on my Cheeb.
Started at 200km just after the build, contacted Dengfu without an answer, so investigated myself and found out the on/off button is not waterproof, I bypassed the switch which solved the problem until last week

After doing some muddy terrain, cleaned the bike to hear the ticking noise again.
Checked all the wiring to the display and motor and opened the battery connector (removed the white smudge) to find out it was moisturized inside! Seems Dengfu needs improvement on the electrics.

Hope this info helps for future owners.

 

[Hagbard]

Thanks @westyB, that ticking noise really is quite worrying.

Has anyone attempted to locate a replacement waterproof isolation switch?

 

[thaeber]

Isolation switch = on/off button on right side of the frame, beside the battery lock?

 

[apac]

Spray everything electrical with ACF50 spray. Bare wire, inside connector plugs, switches.

 

[Hagbard]

Isolation switch = on/off button on right side of the frame, beside the battery lock?

Yep.

 

[Hagbard]

Spray everything electrical with ACF50 spray. Bare wire, inside connector plugs, switches.

Funnily enough I've just received some acf50 from a relative who restores vintage motorcycles. It's not in a spray bottle though, so I'll have to find a small one to use.

Now I've Googled replacement switches I've got a real fancy for an illuminated switch. Now that would be nifty ...

 

[westyB]

Thanks @westyB, that ticking noise really is quite worrying.

Has anyone attempted to locate a replacement waterproof isolation switch?

AliExpress is your friend - IP67 - 24V - latching and with enough electrical skills you can even connect the LED
0.26￡ |16MM 5V 12V 24V 220V LED Car Aluminum Black Metal Switch Push Button Momentary pushbutton switches spring return|Switches| - AliExpress

 

[apac]

Funnily enough I've just received some acf50 from a relative who restores vintage motorcycles. It's not in a spray bottle though, so I'll have to find a small one to use.

Now I've Googled replacement switches I've got a real fancy for an illuminated switch. Now that would be nifty ...

its probably even better to just get a small brush and to brush it on. Do not get it anywhere near your brakes!

 

[RyeNiel]

might be a good idea not to use water hose on these bikes when cleaning.

 

[Kezbee]

Waiting on my frame to come, (Motor and electrics have arrived) so I wondering if 'electrical sealant silastic silicone' applied over the electrical connections from new might seal everything watertight. Would be a pain to remove if I ever had to, but I can't imagine having to pull connections apart very often. might last longer than a layer of grease. Thoughts?

 

[Hagbard]

Like a few people have said, I don't think it's really practical to make the whole thing watertight, it's just the nature of the beast! I am intending on adding some black silicon to the cable entry ports near the headtube, and I have given things a good spray with acf50, but ultimately I suspect I'll be getting the hairdryer out again at some point in the future.

The biggest lesson learnt really is that electric bikes and hosepipes are a bad combination, and so I've resigned myself to never having a gleaming shiny bike, and have added a mudguard to the back end, less to protect me, and more to stop the inevitable spray of crud from coating my bike and giving me the yearning for the pipe.

The good news with a DIY bike is that we know how it goes together, and are therefore less fearful of pulling things apart. The electronics are not terribly complex, and there aren't that many places for water to lurk, so (fingers crossed) resolving such issues is relatively straightforward once the initial "oh cock, I've broken it" fear has subsided.

 

[Kezbee]

Like a few people have said, I don't think it's really practical to make the whole thing watertight, it's just the nature of the beast! I am intending on adding some black silicon to the cable entry ports near the headtube, and I have given things a good spray with acf50, but ultimately I suspect I'll be getting the hairdryer out again at some point in the future.

The biggest lesson learnt really is that electric bikes and hosepipes are a bad combination, and so I've resigned myself to never having a gleaming shiny bike, and have added a mudguard to the back end, less to protect me, and more to stop the inevitable spray of crud from coating my bike and giving me the yearning for the pipe.

The good news with a DIY bike is that we know how it goes together, and are therefore less fearful of pulling things apart. The electronics are not terribly complex, and there aren't that many places for water to lurk, so (fingers crossed) resolving such issues is relatively straightforward once the initial "oh cock, I've broken it" fear has subsided.

Good points Hagbard, I might not overdo the silicone then. The problem is I tend to pamper my Current Yeti SB6 A LOT and wash and clean it after nearly every ride. I might have to learn to be ok with a non-hose washed dirtyish bike.

 

[patdam]

Since 1 years i wash my bike with an karsher (set to low pressure) sin any problem. But true i don't ride ofen under rain and rarely on mud.

I have the first rev of the E10, i have only instal flaps on battery cover (+- alike the new rev) and perform holes on battery lower support to evacuate water infiltration. I assembly all connector with silicone grease, mostly help also to insertion.

I had not found any mark of moisture inside the motot when i had open it. The sealing is perfectly studed, the only problem could come from battery. Rather than try to make it sealed, i recommand to manage at best water infiltration to evacuate it and apply grease on battery contacts. there shouldn't be a problem.

 

[RyeNiel]

I only use water spray for the tires and rims not on the frames.

 

[Waynemarlow]

Guys it’s not a problem using a hose pipe as long as it’s not a powerful spray. In some ways ensuring all the grit and mud around the motor is a good thing and the motor certainly can withstand a good clean. On my last ride the motor area was totally engulfed in mud, it just washed and brushed off, easy as.

Just do the basic stuff like fill every connector with silicon grease, make sure any switches you have are IP rated. Simple things like if it’s a crimp on the wire connector then soldier the tail if it’s in an area prone to getting water on it. These bikes are simple electrics compared to the off road MX, Trials and Enduro bikes and water ingress problems have long been resolved in those sports.

Either spray or polish your frame with a silicon based specialist car wax, you will be surprised how much easier the dirt comes off it with just a light wash. For those without painted frames then avoid that last tip as you will never be able to repair that frame should the worst happen.

 

[patdam]

The only potential problem found is the connector to charge the battery located on frame. I found rust on the connexions (wires side), only protecte by retratable sheath. i have flodded all in an silicone compound (and store spare socket)

 

[demondazza]

Hi All,

I've had my Cheeb for a few months now and loving it. However, I've got an issue that is driving me mad!
Over time, the M600 motor has developed a really annoying 'slipping' issue. If I stop pedaling, whether from stopping or coasting, when I begin to pedal, the cranks do not immediately engage and they rotate 180 (sometimes 360) before engaging the chainring to drive the rear wheel. It's rather dangerous because it has caught me out a few times when I need to apply pedal power and it simply slips making my legs exert force with no resistance - it also makes me look like a bit of a tool. I've opened the motor and had a good look around. Everything appears to be in perfect shape. No wear to the gearing, nothing wrong with the electrics from what I can see. I regreased everything and put it all back together and for a couple of rides, it was perfect. However, it has now begun to 'slip' again. I'm not sure what to do. It's almost like there is a clutch that isn't working correctly. I know they don't have clutches but there is definitely something going on that's not allowing the pedals to drive the chainring. It's very intermittent too. It can slip when hardly any pressure is applied to the pedals or it can happen when a lot of pressure is applied - it makes no difference. The bike is a lot of fun but this issue is tarnishing it somewhat. Any suggestions would be appreciated! Many thanks

 

[Sheff73]

My guess is that you have a 'one-way' bearing (sprag clutch) issue... Have a look at this vid as it shows the M600 stripped down. There are 2 inside there unfortunately.


Has the motor done many miles?

 

[Sheff73]

Also have a look at this thread. Might be as simple as a re-calibration of your controller via the BESST tool (if the motor is going into reverse every now and then?) or again a one way bearing issue...

Bafang M500/M600 thread

Since this seems to be an interesting motor, why not have a separate topic for it? I'll start with three quotes I have found about the motor on this forum, feel free to add more information that you can find. Over the last couple of days I had heard that there had been reports of the M600...

endless-sphere.com

 

[demondazza]

Thanks for the advice and links. The motor has only done 600 miles so far. Having opened the motor, on inspection, the one-way bearings appeared to be fine as this was my initial thought too. They worked fine when turning by hand. I think it could be electronic as you said. The only other thing I can think of is that it might possibly be something to do with the throttle control which I installed (mainly for a bit of a joke with the guys I ride with).
I did build the DIY Canbus lead from the endless sphere forum and changed the speed limit and wheel size. Thinking about it, I had no issues before doing this...ummmm. I might need to get a BESST tool.

The strange thing is, with all the research I've done, I've not found anyone else experiencing the same issue with this motor so I guess that's a positive

 

[Waynemarlow]

I've seen the same problem rarely on my TSDZ2 motors, always the one way bearings and always they work fine when turning by hand. I've even taken a couple apart trying to see what the problem is but they always look perfect. The ones we replaced were always only a problem in colder temps and we put it down to incorrect grease in the bearing. But if the motor was working you would expect it to warm pretty quickly so we couldn't really isolate it down to temperature.

It will be only one of the bearings, the one that isolates the crank and it will be clear to see which one. Good quality replacements are not so expensive.