[SOLVED + PHOTO ATTACHED] Rubbing/friction in E+ after losing pressure

[Flavour]

Hi,

 

I've just got back from a ride on my E+.

When riding on a flat sidewalk, I've suddenly noticed my tire pressure was pretty low (but not flat). It was instant, I could immediately feel the difference, like when getting a puncture.

So I came back home, first riding very slow (riding faster was unstable), then decided to carry my Ninebot to not risk anything.

 

I thought I've got a puncture or something and will need to patch the inner tube again and inflate the tire.

But I probably hit another 100 km and it was just about time to inflate the tire. Besides, the inner tube was patched once before and when I got the puncture, I couldn't ride at all, because the tire was completely flat.

 

So, I inflated the tire to ~50 psi.

 

The point:

- The air pressure is stable, no patching needed, I think the inner tube is OK,

- When riding slowly (5-10 km/h) everything is OK, but when I ride faster, I hear some friction/rubbing and my E+ breaking light are constantly on, it works literally like something is breaking when I go faster than 10 km/h. When I slow down to ~10 km/h, the break lights turn off again and the "friction" is stable,

- When I lift my E+ and turn it on, the wheel rotates without the friction noise and it looks as usual, but the tire doesn't look 100% straight when it's moving (it's maybe bended a bit? But how is that possible without hitting anything? Besides it doesn't look like it causes any friction)

- Overall, I get an impression my E+ is unstable to ride - it wobbles a bit on higher speeds and I can hear rubbing noise sometimes.

 

First, I thought it was the vault causing the friction (it's poorly designed, because sometimes after inflating the tire, the vault can stand out too much and I need to inflate it again to fix it), but after making sure the vault is positioned well and even after inflating the tire again to ~40 psi, the issue still exists and I'm sure it's not the vault, because a vault related friction sounds differently - it's louder, it's not constant, it's more like hitting, not friction, and most importantly - I would be able to hear it when I lift my E+ and turn it on "in the air". 

The friction noise now is hearable only when I ride higher speeds.

 

What can cause the issue?

 

I didn't hit anything, didn't ride on a flat tire (the pressure was lower, but still rideable and stable to ride), my E+ looks like a brand new, it almost doesn't have any scratches.

 

Thank you.

 

 

[SuperSport]

Mine was making a constant rubbing noise today too.  I had to shake it about a bit to get this out.  Some sort of plant stem.  It sounded like Metal on Metal.

And yes, I DO have a German Shepherd, as seen on the carpet.

 

[Flavour]

Thanks. I don't think something got inside it, but I'll disassembly it completely and check :-)

[SuperSport]

Did you ever get this sorted?  I'm always on the lookout for things that might happen to me in the future so I can hopefully fix them while on the road.

[Flavour]

Not yet, will disassembly it today. If I don't find anything causing the issue, probably will send it to the seller for guarantee-repair.

[Flavour]

It turned out the tire is damaged, it looks like I have a "bubble" in one place. After I removed completely the right cover (battery side), it was clearly visible that one piece of the tire causes the friction.

I tried to decrease the pressure and it was all ok until I stood on the pedals.

It looks like the tire is completely damaged, but I don't know how it happened. 

Fortunately I've already ordered new tires (original and winter tire) and inner tubes, so when the package arrive I should be able to ride again :-)

What bothers me is why Ninebot engineers decided to leave only ~2 mm margin between the tire and the shell? It's a very low margin and it can easily cause friction when jumping or when the tire is damaged like mine. Even decreasing the pressure to ~30-40 psi didn't solve the issue (but it helped a bit). With 50 psi it was completely unrideable. I think bending a little the metal part where the friction occurs (it's the metal on the back and it has the thinnest margin area) would solve the problem, but replacing the tire it's definitely better idea

I attached a photo so you can take a look. Could you also tell me are these scratches on my motor normal? How it could happen? It looks like the motor was scratched by the shell or maybe some stones or something?

And does your Ninebot lights up the "braking lights" sometimes even if you don't break? Or it's only mine because of the friction?

[dmethvin]

Nice detective work! You might try deflating the tire a bit and pushing the high spot down to see if it will seat lower on the rim. 

As far as the scrapes on the motor hub, it looks like something (a rock, or maybe that plant stem next to your dog hair above) got jammed in the case and was rubbing off the paint. If that rubbing was always happening I'd think you would have heard it. Just to be sure you could clean it up and smooth off the scrapes with some fine sandpaper, then spray some new flat black paint on it. If the scrapes come back quickly then something must be rubbing and that's not good.

[Flavour]

34 minutes ago, dmethvin said:

Nice detective work! You might try deflating the tire a bit and pushing the high spot down to see if it will seat lower on the rim. 

As far as the scrapes on the motor hub, it looks like something (a rock, or maybe that plant stem next to your dog hair above) got jammed in the case and was rubbing off the paint. If that rubbing was always happening I'd think you would have heard it. Just to be sure you could clean it up and smooth off the scrapes with some fine sandpaper, then spray some new flat black paint on it. If the scrapes come back quickly then something must be rubbing and that's not good.

Actually I did. I deflated the tire so the higher spot wasn't a problem any more when Ninebot was on my floor on the side. But with lower tire pressure, when I stood on the pedals, the bubble probably got some more air (because of the pressure force of my body to the ground) and got a bit higher again.

Overall it's "rideable" with lower pressure, but the friction occurs sometimes on higher speed anyway, but it's not as bad as it was before. I don't think there is a way to save this tire, I have to replace it and let you all know if that solved the issue permanently.

Regarding the motor my guess is that was a rock or something, because I can't see any friction now and it looks like not the whole motor is scratched, so it wasn't constant. Looks like a rock got there, scratched it a bit and quickly fallen off. But I will attach some duck tape and check.