MSX Motor Vibration?

[dieterGRAMS]

Received my MSX from GreenFashion about a week ago. Put 100 miles on it so far. It seems flawless but has a slight vibration at low speed and braking. Almost as if the tire was knobby style. Seems to go away at speeds over 15mph. No audible noises that I can hear. Wheel is still silent. Rode another msx which felt smoother. Not by much tho.

Just wondering how everyone else's wheels are feeling in this regard. 

[WARPed1701D]

Check the tire is seated properly. You may need to deflate it, massage the bead a little all the way round and apply some kind of mild lubricant to the rim (dish soap solution) when re-inflating to ensure proper positioning. A few people have had this issue recently across the brands.

[Xoltri]

Mines the same, I was not concerned about the sound though.  Must have something to do with the way the motor is driven at very low speeds.

[mrelwood]

Mine has it too. I wouldn’t be surprised if the cause was a not-that-optimized motor driving algorithm.

[Xoltri]

2 hours ago, mrelwood said:

Mine has it too. I wouldn’t be surprised if the cause was a not-that-optimized motor driving algorithm.

Well, I noticed that it does it with the wheel off as well so that can't be it.

[mrelwood]

2 hours ago, Xoltri said:

Well, I noticed that it does it with the wheel off as well so that can't be it.

Then we are talking about a different issue. Is the vibration you talk about like a wobble, repeating at every tire cycle? Does the wheel shake if you let the motor spin while lifting the wheel? If so, @WARPed1701D was spot on, the tire needs a re-seat.

[RockyTop]

MSuper v3s+ with 2000 watt motor does it too. Slight rumble feeling at low speed. Like a saw tooth motor controller signal. 

[NECway]

On 7/27/2018 at 3:31 AM, RockyTop said:

MSuper v3s+ with 2000 watt motor does it too. Slight rumble feeling at low speed. Like a saw tooth motor controller signal. 

I'm getting the same thing with Tesla.

[Electroman]

Interesting, will follow but my own is not even here yet for a while so will be a surprise to find out I suppose?

[sWiFt]

On 7/27/2018 at 9:23 AM, mrelwood said:

Then we are talking about a different issue. Is the vibration you talk about like a wobble, repeating at every tire cycle? Does the wheel shake if you let the motor spin while lifting the wheel? If so, @WARPed1701D was spot on, the tire needs a re-seat.

I think I can provide some good examples here, did a few short videos this morning of my brand new MSX. The quiet rumbling sound when the wheel is idling is something I recognize from my IPS and I just think of it as being a natural "balancing" oscillation. It is "grinding" a lot louder when pushed around slightly, nothing i would personally worry about however, please comment if anyone thinks otherwise. Example 1: Sound of an idle MSX motor;

However, I do think I need to deflate the wheel, lube it and give it a massage before inflating it again, as there is a clear wobble when the wheel is spinning freely. I really hope it is only the rubber and not the rim or anything else. Example 2: Short video of wheel wobble;

Example 3: A longer video from another angle;

 

Lastly, I did not have time to reproduce it this morning, but yesterday when I was getting familiar with the wheel in the hallway, I was only going back and forth a few meters at ~4km/h to get the feel of this beast, after a little while there was a sound almost like a tiny motorbike revving up, and then cutting off and starting over.

It kept on doing it even when I just let it rest for a little against the wall. Almost an "alarming" type of recurring sound, quite faint but still clearly audible. The board temp was at 39 degrees C by then so I was suspecting the internal fan was speeding up but it almost felt like it was rubbing against something and shut off, because most small fans I´m familiar with are not really this audible...

Can anyone confirm that the internal fan works like this? Maybe It was balancing at the ON/OFF temperature because some times it kind of revved up and kept on for a second or two seconds before turning off again and going back to the revving up and cutting off-cycle. I think I saw a correlation of this sound to the wattage going up and down, but I´m not confident to make that conclusion just yet.

I will try to stress the wheel a little more and capture a video of it in about 7 hours. Check in for updates!

 

[The Wheel Plug]

2 hours ago, sWiFt said:

a sound almost like a tiny motorbike revving up, and then cutting off and starting over.

It kept on doing it even when I just let it rest for a little against the wall. Almost an "alarming" type of recurring sound, quite faint but still clearly audible.

Yeah this is the fan. In all the videos I've seen and in my MSX the fan makes the same sound. It's audible but not too loud. Your description makes sense though 

[sWiFt]

11 minutes ago, Ryan Sinatra said:

Yeah this is the fan. In all the videos I've seen and in my MSX the fan makes the same sound. It's audible but not too loud. Your description makes sense though 

Thanks for the confirmation, I just had a little PM chat with Electroman who also thinks this is the case, that it was simply balancing on the trigger temperature. I´ll know for sure soon, will give it some "spa treatment" massage before inflating to ~40 PSI again, charge it up a little more and go from there. 

[mrelwood]

Yup, it’s the fan. I’ve never before met a fan programmed to run in a loop like that. Don’t be alarmed when it runs at full speed, the shell of the MSX works like an acoustic guitar and the fan noise is really quite a loud one. I separated the fan frame from the shell and it tamed the noise a bit.

Regarding the first video, it has the same sound of a boiling kettle that I have on mine, I suppose it’s normal for the MSX.