Broken display within ten days ownership

[Carlbooze]

Hello All:


December 10th, my Shengmilo M90 Mtb arrived, at my home, but by 10 days later both the PAS, throttle and walking mode had stopped functioning. It happened after setting the display one day, before going out for a ride. Then I discovered that nothing worked except the light, when I tried using any of the pas/throttle functions. Also, the front brake wouldn't work after I loosened some tension in the cable, which then caused the bike not to stop after pressing the lever

After contacting Shengmilo to detail my problem, the dealer narrowed the problem down to the display.

A part of me really wanted to pack the ebike back up and send it back, but since the dealer was ready to send me the parts I needed, and because I knew that I could just as easily encounter another problem from buying another new ebike, I declined returning it.


M90 Mtb details: 29 inch, rear drive hub motor, with 500 W 48volt 17ah battery

Brakes - Hydraulic front and rear

Display - M5 lcd


I'd like to know if anyone else has had similar or worse problems with a brand new ebike, and we're the items fixed to your satisfaction?

Also, how could this happen with a new ebike? Had this been you, would you have sent the ebike back?

Lastly, if the aforementioned problems weren't involving the display, could it then be the controller malfunctioning at such an early phase in ownership?

Thanks, I'd appreciate most any response to my rambling.

 

[Carlbooze]

And, because of my hip replacement, it was suggested that I not ride bicycles until May. I still have to get around, so I bought myself an electric scooter.

So, in these intervening weeks, I'll have time to learn how to install a controller (if necessary) a display (totally necessary) and a front braking system (completely necessary) as the manufacturer (Shengmilo) is offered to send me these replacement parts from China.
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Carlbooze 1 mW

 

[Carlbooze]

Hi E-HP:

Now, after having seen a video on adjusting hydraulic brakes, I'm wondering if the problems I have with the throttle, the pas, and the walking mode might just be a matter of a brake adjustment to get everything going again?

I ask because the bike doesn't stop when I press the lever, and that's because the brake power cable was too tightly wrapped around the front fork.

In any event I'm waiting for these parts from China. I know that I said that I was going to disconnect the brake power cables from inside the controller, in order to ensure that the throttle wasn't working because of the brake sensors/power cables being out of whack, but I got cold feet at the last minute.

To be honest, I'm petrified at the thought of taking apart and reassembling this thing!!!!!

Since I can do nothing but ride my electric scooter, and wait for my parts, then that's what I'll do.

 

[amberwolf]

Now, after having seen a video on adjusting hydraulic brakes, I'm wondering if the problems I have with the throttle, the pas, and the walking mode might just be a matter of a brake adjustment to get everything going again?

That's exactly what we already proposed, and have given you at least two very easy methods of testing if this is the problem, one of which does not require any disassembly of anything at all.

If you don't want to test to find out where the problem is, that's your call, but it's going to be tough to fix that way, without just replacing parts until it works, or you run out of parts to replace.

 

[E-HP]

Hi E-HP:

Now, after having seen a video on adjusting hydraulic brakes, I'm wondering if the problems I have with the throttle, the pas, and the walking mode might just be a matter of a brake adjustment to get everything going again?

I ask because the bike doesn't stop when I press the lever, and that's because the brake power cable was too tightly wrapped around the front fork.

In any event I'm waiting for these parts from China. I know that I said that I was going to disconnect the brake power cables from inside the controller, in order to ensure that the throttle wasn't working because of the brake sensors/power cables being out of whack, but I got cold feet at the last minute.

To be honest, I'm petrified at the thought of taking apart and reassembling this thing!!!!!

Since I can do nothing but ride my electric scooter, and wait for my parts, then that's what I'll do.

Just power the bike off it there's an issue. Troubleshooting is a series of steps used to isolate the problem. Seldom is the first guess the fix and everything is fine. The brake cutoff is one element that can cause PAS, throttle and walking mode had stopped functioning. So, unplugging it and observing the behavior can help determine or eliminate that as an issue.

 

[Carlbooze]

Shucks, I am so confused. I have to read and try your instructions again. I thought that you were proposing those things, as I wait for the parts, in order to make sure that there wasn't another cause for the throttle/pas trouble.

For instance, the brake power line disconnection you suggested, I was going to try, after first finding a video on how to do it correctly.

I am, by no means deliberately ignoring your suggestions!

I haven't been getting much sleep, due to hip pain. And, the pain meds are definitely a barrier to clearer thinking.

That's why my post is redundant. I know that I probably repeated stuff, or overlooked suggestions, thinking that I read them.

That, coupled with my fear of making matters worse, kept me from doing much of anything with this bike.

Tomorrow, I am reading again without fear and with more clarity.

Thanks

 

[Carlbooze]

I am so confused. I have to read and try your instructions again. I thought that you were proposing those things, as I wait for the parts, in order to make sure that there wasn't another cause for the throttle/pas trouble.

For instance, the brake power line disconnection you suggested, I was going to try, after first finding a video on how to do it correctly.

I am, by no means deliberately ignoring your suggestions!

I haven't been getting much sleep, due to hip pain. And, the pain meds are definitely a barrier to clearer thinking.

That's why my post is redundant. I know that I probably repeated stuff, or overlooked suggestions, thinking that I read them.

That, coupled with my fear of making matters worse, kept me from doing much of anything with this bike.

Tomorrow, I am reading again without fear and with more clarity.

 

[amberwolf]

To save you some time, it's the bolded section in the quote from a prevous post below:

If there are ebrake switches in the levers, and the tension is loose enough to let the lever "open" a bit (possibly even little enough that it is hard to see this happening), the switch would disengage the entire system--it would still power on and you could access everythign as normal, but the brake would be "on" as far as the controller is concerned, telling the motor not to run.

To verify this, push the brake lever as fully to the "off" (unpulled) position as you can, and see if the system runs then. If it does, then the lack of tension on the cable is what is causing the entire problem.

An alternate test is to unplug the cable from the brake lever that goes to the rest of the wiring--most systems, with the cable unplugged, assume the lever is not activated and so allow the motor to run.

Hopefully this is the entire problem, which means you can simply readjust the brake cable as it was, and fix the problem. Or have it done by a bike shop if necessary.

 

[Carlbooze]

Thanks a lot!!!

 

[amberwolf]

I do have a question though. You now state (in a recent post)

I ask because the bike doesn't stop when I press the lever, and that's because the brake power cable was too tightly wrapped around the front fork.

I cant' see how loosening the tension of a hydraulic brake hose or cable would change how it is wrapped around the fork? I'm curious because it may affect how you end up repairing the problem.

Also, whether it is actually a hydraulic fluid hose, or a cable sleeve, matters. Do you have hydraulic brakes, or cable brakes? If hydraulic, are they fully hydraulic, meaning a fluid hose from lever to caliper, and the pressure reservoir on the brake lever? Or are they cable-actuated just like regular cable brakes, but with the pressure reservoir on the caliper?

If they are not cable-operated brakes, but only pure hydraulic, then there is no cable tension you could possibly loosen (you could let fluid out, but that doesn't change the tension of the hose as there isn't any). That may change (or eliminate) the possibility of the ebrake switch causing the problem.

 

[Carlbooze]

Hi There:

Now, I have to really check these brakes, but the bike was advertised as having hydraulic and not cable-assisted hydraulic brakes. So, I 'll check

Now I know why it seems like I haven't read and followed the suggested methods, that you kindly put forth:

It's because there's so much rich detail and information in each of your posts, I must go back a few times to make sure I understand everything you wrote!

Both yourself and E-HP are operating on a much higher grade level (frequency even) than my poor brain can muster. Besides, you're no doubt professionals at this, so it takes me a little time to catch up (read up).

 

[Carlbooze]

About these brakes:

I'll probably need to attach pics, because from what you described (i.e.fluid, cable, caliper, reservoir etc.) it combines those elements to make the brakes that are presently on this bike. So it's not easy for me to determine which type they are.

 

[Carlbooze]

About these brakes:

I'll probably need to attach pics, because from what you described (i.e.fluid, cable, caliper, reservoir etc.) it combines those elements to make the brakes that are presently on this bike. So it's not easy for me to determine which type they are.

 

[Carlbooze]

Hello Amberwolf:


An alternate test is to unplug the cable from the brake lever that goes to the rest of the wiring--most systems, with the cable unplugged, assume the lever is not activated and so allow the motor to run.

Question regarding this test you mentioned:

Will this test (yours is easier) accomplish the same aim as disconnecting this cable from the brake power sensor connecting directly to the controller? If so, I wonder why the videos I see, elect this method (disconnection from the controller) as opposed to your method (will try now)(disconnection from brake lever) which is much easier to access?

Both methods seem to test the same thing!

 

[Carlbooze]

Another Brake test question:

An alternate test is to unplug the cable from the brake lever that goes to the rest of the wiring--most systems, with the cable unplugged, assume the lever is not activated and so allow the motor to run.

When I went about starting to do this, I wasn't sure which brake cable to unplug (see photos)

 

[E-HP]

Which of the pics shows these areas (but not so close up that you can't see what's going on)?

"Also, I tried to manually loosen the brake cable, after I found the tension to be so tight that it cut through the plastic surface of the cable. But, as a result of my adjustment, the bike wouldn't stop when I pressed the lever."

"I ask because the bike doesn't stop when I press the lever, and that's because the brake power cable was too tightly wrapped around the front fork."

 

[Carlbooze]

Hi, E-HP:

So, I was trying to find out which cable to unplug in order to do the testing.

First cable (thinner than the other one with the cap)

And, this same cable is in the photo (worn)

The brake pictures are the same area of the front brake, just shown from two different sides.

The cable that's showing some wear (due to my attempting to unloosen the bolt) is the brake sensor. Also, if you look closely, you will see a small cut under the nut. The cut happened because prior to this I switched out my handlebars (I forgot that detail, sorry) and this placed enough strain on the cable that the plastic tore. The fitting of the handlebar forced the cable closer to the fork, so that I looked for ways to loosen it.

This is also why the same cable (which was so tight and nearly around the fork) that I moved and then tried adjusting its' cable leading up to the brake. It's also the brake that won't stop the bike. This brake sensor cable (at the other end) feeds into the controller. (Controller housed in section under battery.)

The thicker cable with the cap is the brake itself, whose other end feeds into the rotor, caliper etc. to stop the bike.

According to the video I watched on the similarly equipped Shengmilo MX02, I think that's how it's set up on my bike, which is the Shengmilo M90 ebike.

 

[Carlbooze]

Hello There:


Well, I think that I followed your testing instructions, by disconnecting the cable near the brake lever.

Next, I'm going to disconnect the brake sensor for the front brake, from the controller, and see if that then allows to motor to run. This refers to the video I saw the other day.

 

[E-HP]

Hello There:


Well, I think that I followed your testing instructions, by disconnecting the cable near the brake lever.

Next, I'm going to disconnect the brake sensor for the front brake, from the controller, and see if that then allows to motor to run. This refers to the video I saw the other day.

If it still doesn't run after you remove the cutoff switch, then the cable could still be shorted from being mangled. Right now, the controller thinks it's seeing a closed circuit; which could be a bad/stuck switch or it could be shorted conductors.

If the conductors are broken under the cable jacket, they could short, or be open if you move the cable. If open, then pulling the brake lever wouldn't stop the motor, since the cutoff is downstream of the broken conductors. If shorted, the bike won't run, since the controller thinks the cutoff is activated.

PS. this assumes that by "sensor" you mean cutoff switch or magnetic cutoff switch. if the bike has some other type of cutoff that uses sensors, the above may not apply.

Also, I tried to manually loosen the brake cable, after I found the tension to be so tight that it cut through the plastic surface of the cable. But, as a result of my adjustment, the bike wouldn't stop when I pressed the lever.

 

[Carlbooze]

Hi:

Yes, it's the one that caused the problems. Now, if I took a hex key and loosened it as much as I could without removing it, and nothing happened (motor didn't engage), then I don't know what going to the other end (unplugging it from the controller) will accomplish, but I 'll see what happens.


Thanks

 

[Carlbooze]

Photos showing the brake, the two cables extending out from the lever (the cable that's beat up a little, has a tiny puncture near the nut) is the brake sensor. The other end feeds into the controller.


This is the one causing all the mayhem.

 

[amberwolf]

Before doing all that stuff that might have damaged things further (becuase those are almost certainly not the connectors--the connectors are wherever the brake cable plugs into the cables that go to the controller), did you try the first, easy, completely nondestructive test?

To verify this, push the brake lever as fully to the "off" (unpulled) position as you can, and see if the system runs then. If it does, then the lack of tension on the cable is what is causing the entire problem.

If so, what were the results?

 

[amberwolf]

The cut happened because prior to this I switched out my handlebars (I forgot that detail, sorry) and this placed enough strain on the cable that the plastic tore. The fitting of the handlebar forced the cable closer to the fork, so that I looked for ways to loosen it.

This is a major change to the bike, usually requiring completely disconnecting everything on the handlebars so they can be removed from the bars and then the bars removed from the bike, then new bars installed and everything reinstalled on the bars and then reconnected.

Did the bike work correctly after the handlebars were changed?

If not, the problem could be any of the things that were done during this modification.

 

[Carlbooze]

Hi:

Yes, the bike worked beautifully after I changed the handlebars. It's just when I tried to mess with the cable that things went awry.

 

[Carlbooze]

Hi:

Yes, the bike worked beautifully after I changed the handlebars. It's just when I tried to mess with the cable that things went awry.


The nondestructive test, I believe was to push the brake lever out, I think, but I have to read the posts again.

Extending the lever had no effect whatsoever. Infact it the lever is out as far as it can go, and there's slack in the cable.

It's the sensor cable and the brake adjustment that I messed with.

 

[Carlbooze]

Hi:

Yes, the bike worked beautifully after I changed the handlebars. It's just when I tried to mess with the cable that things went awry.


The nondestructive test, I believe was to push the brake lever out, I think, but I have to read the posts again.

Extending the lever had no effect whatsoever. Infact it the lever is out as far as it can go, and there's slack in the cable.

It's the sensor cable and the brake adjustment that I messed with.

But, I won't mess with anything else until I hear from you!