Road Runner vibrates

P

praskal

1 W
Joined
Dec 25, 2007
Messages
60
Location
Corvallis, Oregon
I have a front wheel road runner motor on a full suspension MTB. I have a 25amp controller. I have a 48V 10ah LiFePo4 pack. I have one question: the hub motor vibrates quite forcefully when I throttle and upon sustained speeds. This vibration never happened with my old X-Lyte hub motor (the old Phoenix). The X-Lyte was a totally silent ride for the whole range. I wonder if I should be worrying about the humming/vibrating of the road runner? Is this a problem?
 
I have been using it since december '08. The motor has always vibrated since the first time I used it. That's why I figured it was normal. Anyway, I checked all the leads to the motor, controller, batteries and everything looks good. I have no idea how I would troubleshoot this. I really don't feel qualified to remove the controller and open it up to look for a bad mosfet or hall sensor. I have no idea what I would be looking for? I certainly do not think that I should open up the hub motor and look for an errant wire.

I use the ebike to commute exclusively. I have a 48v 25amp controller. 48v 10ah LiFePo4 batts. It has worked in it's vibratory state for 5 months so far. Hmmm. What next step should we take??

Gracias,

patrick
 
maybe the guys who ride C'lytes can tell about the vibration but it seems like you have had bad hall sensor wiring. either it is miswired from the start or the wires are not making good contact if you have vibration, which i am assuming is more than just normal cogging.

how fast does it run? that could be an indication, but the C'lyte plugs should be set up already to be properly polarized. it could be a bent pin in the hall sensor plug or a wiggly connection in the phase wires.

i cannot believe you would have blown the controller from the first day if it was new then.
 
I dont have that motor but it could be caused by several things. The PWM of the controller is really low. If that were the case all the controllers would be doing it. The controller just could be stuck at the resonance frequency range and or harmonic of the motorr. My GM Regen controller has a shuttering problem at high speed. But its not a vibration more of a skip. If you can give detail on the noise or perhaps a safely recorded video. I think its just the resonance of the motor. If it was a sparrow motor i could definetly tell you it was the controller.
 
Is the wheel true ?
 
what kind of speed and range are you getting? and on what kind of battery?
Do you know your wattsd per mile usage?

Vibration could be anything from Some major damage to nothing more than a local anomily with that motor. From what I understand, the original motors are all hand wound, and QC in china is non exsistant, so no two motors are alike. If your preformance is close to normal for other motors, it may not be anything broken.
 
The wheel is perfectly true. I have a LiFePo4 48V 10ah pack, which has been great (since I used to have SLA). The top speed is 23mph. I don't know the range but I think it is around 12 to 15 miles. I don't know the watts per mile or any other such info because the 48V 25amp controller has no connector for my cycle analyst, which irritates me quite a bit (but I do not feel qualified to open the controller and solder in a new connector).

I emailed Mike from ElectricRider.com and he said "It is either a broken power wire on the motor, or a blown MOSFET inside the controller. Check your motor wires all the way to where the enter the motor for any damage and let me know. It should be a smooth as the Phoenix."

I'll go look at the hall sensor connector to make sure that a little connection isn't bent back or something...
 
Ok, just checked all connections and everything looks fine. I loosened up the leads a bit and reconnected everything. I just rode down the block and yes, still vibrating when I apply the throttle. It still accelerates just fine, but it just vibrates alot when I lay on the juice.
 
23mph is about right for the top speed, give or take a couple mph based on your weight, size, tires, ect. 25 would be ideal, but a broken motor wire would cause you to go a LOT slower.
your range of 15mph based on your 480 watt pack would give you a watt per mile of 32, if your using 100% of the pack. I hope not, and if not, that number would be better. I get around 29 watts per mile in "normal" riding measured, so even 32 wouldn't be too bad.

It doesn't sound like an electrical issue. your motor is preforming too well to have something blown or broken.

My guess is either a bearing isn't rolling smooth under load, or its just a characteristic of that particular motor.
 
yes, a bad phase wire would never let him go that fast, and if it had bad FETs it would be dead.

you should try to find another controller to test the motor with. anybody close to you who you could borrow one from? if the controller is bad from the start then dave at electricbikes may help out, ask him if he has a used one that works that he could loan you to test the motor.

could be bad bearing too, hard to tell when people say shudder, do they mean stutter or flutter, or butter? one of those things where you gotta be there.
 
The guy from ElectricRider.com suggested I send the controller in to them: "If you don't see any damaged wires, it's most likely the controller which is much less expensive to ship. Please ship the controller back for diagnosis/repair."

But I can't be sending anything anywhere, since I use the ebike to commute. What the hell? This is ridiculous. I asked him if they would send me a new one and I'll send mine back. I'm sure he'll say no.
 
maybe he will loan you a used one for the while just to test the motor, or maybe someone else here will loan you one.

i assume you can investigate any wheel bearing problems by rotating it by hand, doesn't sound like a wiring problem on the motor either. still haven't ruled out intermittent hall sensor problems though. that's why i asked about the connections.

maybe offer him a deposit on the loaner so he knows it will come back. we are all nothing more than an electronic blip on the net, but you are a customer, and you did tell him it had a problem from the start.

this is dave at electricrider, right? he got burned bad on batteries last year when he got a lot of poor quality chinese source lithium cells returned and he supported a warranty on them as i recall.
 
I'm going to call him tomorrow. The guy helping me is named Mike. He said he's never heard of the problem. Hmmm... weird.
 
Dave suggests I use a voltmeter to see how much the voltage is sagging under load. The LiFePo4 may not be enough when I throttle. I'll check it out...
 
Ok, I went ahead and was able to connect the voltmeter contacts to the system. This was after I rode home 5 miles, so the batt pack was certainly not fresh. Right away I got a reading of 50volts at rest (48V 10ah LiFePo4 pack). I then rode up an incline, no pedaling. Upon full throttle I did get the load vibration, but the voltmeter only dragged down to 48 and only as low as 46 upon prolonged load testing (and vibrating).

So it would be hard to say that the load vibrating is due to the 10ah batt. I don't know, what do you think?
 
I said that I had ridden 5 miles already with it. I'll test it later when it's fully charged.
 
i guess i'm beginning to think like dogman that it is too much for the battery and the BMS is regulating the output somehow, maybe rapidly and causing it to shudder. i thought it just turned off though. but don't know if it could be a low cell too. but 10Ah is not enuff maybe.
 
My thing is ithe bms is going to trip its going to trip. If its a cheap controller like one i had in my brushed days... people suggested on the forum that my 60v 100A controller was pulling so much current it was causing the lvc to kick in and as soon as the voltage rised enough to cut back on it did. But it did this on acceleration and it happen many times per second to where it felt like vibration. But he has a clyte controller. The odds of it happening to a somewhat high quality controller is slim but what do i know.
 
Well, when fully charged the LiFePo4 pack rests at 57 volts. When
riding, the voltage dips to the low 50's. Until a few miles into it,
then the voltage sags to 47, 48 with a big load.

Basically, the whole ebike settup runs just fine with good power and
appropriate distance for what pack I have. There just is a vibration
with deep loading. I suppose this could be that the batt pack is not
providing enough current for the demand. This makes me think that the
longevity of the batt pack will be reduced. I'll maybe have to replace
it in 4 years rather than 6, or something like that. By that time we
should all be riding with EESTor EESU's, right...
 
I think I finally know why the motor vibrates. I have the road runner motor on the front wheel of a full suspension mountainbike. This means there are front forks. My sense is that the rpm's of the motor causes some sort of vibration at high torque within the front shock.
 
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