Strange oscillation at 40 to 50 mph?.

[frog13]

The search engine is not my friend today . My question is : Approximately 40 to 50 mph I'm feeling a strange oscillation . It was a bit windy today . Tires have proper air . The bike only has 254 miles on the clock . Several days ago, the weather cooperated in SW Ohio and I took the bike out for 40 to 50 miles and didn't notice the aforementioned oscillation? .
Any thoughts . This is a new 2015 pcx 150 . TIA

[yak]

"Oscillation" is not very descriptive. Is the bike shaking (vibrating)? More toward the front or the back? Are the handlebars shaking in your hands? Are there any sounds associated with the problem? If you slow from 50 to 40, does the problem go away? As you speed up to 40, what is the first thing you notice about the problem?

[frog13]

The handlebars are not shaking . No sounds associated , no strange odors . It seems to dissipate slowing down to 40 mph . I'll also check to see if I lost the wheel weight (for tire balancing) up front?.

[SECoda]

Feeling an oscillation. Any idea of frequency? Say how many times per second?

[Mel46]

Sounds a lot like a tire is out of balance. Have the dealer check it. Some of the members here use some kind of beads in the tire to keep them in balance. I dont use them so I can't recall the name. Dynabeads I think.

[SECoda]

+1. That was my guess. When I bought my PCX new it had a box cutter cut on the rear tire. They changed it and balanced both the front and rear and I think my bike has been extremely smooth at all speeds. Weights were necessary on both wheels.

[homie]

Put it on the C-stand and rev it up slowly holding the front brake (awkward but safer). Don't blast off! See if you can isolate it to rear wheel or engine.

[frog13]

Lots of helpful information now , thank you , that's what I was initially looking for . I'll check the aforementioned possibilities out , thanks again .

[geek77]

When I bought mine (used) it was shaking at speeds above 80km/h.
I was quite worried actually.
I changed the oil for a more appropriate one, and the shaking went away. I was not expecting it to, but it did.
Try the cheap and easy solution first, change the oil, preferably at Honda, or at least use the oil that Honda recommends there.
P.S. And be careful with the oil level, if doing it by yourself. It matters.

[sendler2112]

Nice try.

[frog13]

Geek77 , interesting post , I'll do this . Did you use a non MB rated oil or was it overfilled or both .

[sendler2112]

Geek77 , interesting post , I'll do this . Did you use a non MB rated oil or was it overfilled or both .

Your bike has 400 miles on it. And you already changed the oil.

[frog13]

400 miles ?. Where did you dig that number out of ?.
If someone did change their oil at that interval , what's the issue ?.

[sendler2112]

400 miles ?. Where did you dig that number out of ?.
If someone did change their oil at that interval , what's the issue ?.

Approximately 400. Whatever. The bike is brand new. Just ride the thing. You had 200 miles on it. Exactly. When you changed the oil on 11/16.
.
The issue is that now you are thanking someone for telling you to fix your strange oscillation by changing the oil. Again. When you already just did that.

[frog13]

Thanking them for info regarding the potential sensativity of a new machine , which I've never owned before . I was slightly overfilled , remedy this and perhaps clear up an issue , being polite is always a good policy , take note please .

[geek77]

Mine came with 16000km and the oil was just worn out garbage.
I always change the oil as soon as I buy some car or a scooter in this case.
I think the oil was so old that it was the reason for the shaking. Or maybe the amount.
I had it changed at a bike shop and the shaking went away.
It doesn't make much sense, what can I say.
But since it happened to me personally, and since the change was so noticeable - I felt like I had to share my experience. :-)
400miles? From the dealership? You could ask them maybe, or try another one for comparison there.
I would expect a new scooter to run smoother than bacon.

[frog13]

Thanks for sharing geek77 .

[SECoda]

So did you have a final resolution?

[sendler2112]

I would expect a new scooter to run smoother than bacon.

Actually this is not the case. There are several areas of the PCX, or any small scooter, that are common to cause vibrations and oscillations. The PCX drivetrain has a conventional CVT trans. The variator sends power to the rear wheel through a loosely fitted rubber belt and a centrifugal clutch. Clutch shudder and belt shudder on take off first thing cold is normal. The bottom of the belt has less power and tension on it than the top and goes through various harmonics at different speeds which can be felt and it can even be seen that there are rub marks inside the belt case where the belt is slapping. The bias ply tires change roundness on a daily basis depending on how much they flat spot during the time they are parked. My Honda dealer does not even have the correct fitting to put the rear wheel on the balancer and my PCX had no wheel weights on the rear to begin with so I use Dynabeads in the tires front and rear which work really well to smooth out the tire vibrations. But even with that, some days the tire vibration is better than others. Slight printing of the pad on the front rotor for bikes that sit is also common which will cause a slight brake pulsation. If I really try to nit pick it I can incite a barely perceptible steering head shake at highway speed if I intentionally ride very loose on the handlebars and make a quick jab on one side or the other. Supersport bikes have steering dampers to quell this. The PCX is a great machine and there is really nothing else like it's advanced styling and fuel economy but any design has trade offs and price point decisions.

[frog13]

Sendler 2112 . Great explanation , thank you .