Strange oscillation at 40 to 50 mph?.

[homie]

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.

Wow! somebody has had a second cup tonight this was more comforting than a warm blanket and hot cocoa... nice train of thought there sendler. I would have to agree, it's not a luxury vehicle nor does it command a premium cost to own, it's a mini bike LETS RIDE IT until something falls off and then get another

[geek77]

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...

Oh I agree with you 100%. A scooter will always vibrate.
I just expected a new scooter to have less vibrations then a used one.
Or maybe not even that, you are right.

I also had my brake pads and clutch pads sanded with a dremel, to make sure there are no glazed slipping parts. Also a very pleasant result.

Now with a Malossi variator and Athena belt, it seems to vibrate just a bit more that before. Just a tiny bit. I believe it is normal for this variator and belt - they are a bit more "flexible" and therefore shaky.

But my excessive vibrations above 80km/h with the original variator went away with the oil change. I swear.

[frog13]

Try not to be too concerned geek77 . If the oil change did your bike some good , perhaps that info will assist other riders in the future , good show !.

[MikeP]

I just had some Pirelli diablo tires put on and Dynabeads 2oz per wheel for balancing. I changed the oil and overfilled it by mistake. Perhaps 50-100 ml. I thought the bike was level when filling it, but it was not quite. Thus the overfill. Took the bike for a test run, noticed a slight vibration in the rear above 80km/h. Any ideas? Or am I being hypersensitive having done the upgrade? Should I siphon off the excess oil, or is it ok? Thank you all in advance for your help.

[homie]

I just had some Pirelli diablo tires put on and Dynabeads 2oz per wheel for balancing. I changed the oil and overfilled it by mistake. Perhaps 50-100 ml. I thought the bike was level when filling it, but it was not quite. Thus the overfill. Took the bike for a test run, noticed a slight vibration in the rear above 80km/h. Any ideas? Or am I being hypersensitive having done the upgrade? Should I siphon off the excess oil, or is it ok? Thank you all in advance for your help.

People don't show a lot of confidence in the beads. From what I understand they balance your wheel each and every time you roll out for as long as they are in there? Maybe stop and have another run to see if its consistently vibrating. One of those harbor freight motorcycle wheel balancers would come in handy at this point but with the re-balancing beads I think its too late for that.

[sendler2112]

These are very light bikes that go pretty fast. It should be no surprise that you will notice every slight vibration. I like the dynabeads. Most shops can't balance the rear wheel of the PCX anyway so they are the best alternative. Since you think the vibration is coming from the rear, you could run the bike up on the center stand and see if it shakes in the back. Also, watch the new tire closely as it spins slowly at idle. It is normal for all tires to have a certain amount of out of roundness. You can't change this but it would give you an explanation for your vibration. Along with the normal belt oscillation that I mentioned above.
.
You can easily let some oil out the drain plug to correct the oil level by unscrewing it with your fingers and holding it in place to slowly let some oil out, and then screw it right back in. Metal seal rings can actually be reused many times with no issues. But unless it is drastically overfilled, oil level or differing oil chemistry cannot be "felt" as a vibration.

[you you]

These are very light bikes that go pretty fast. It should be no surprise that you will notice every slight vibration. I like the dynabeads. Most shops can't balance the rear wheel of the PCX anyway so they are the best alternative. Since you think the vibration is coming from the rear, you could run the bike up on the center stand and see if it shakes in the back. Also, watch the new tire closely as it spins slowly at idle. It is normal for all tires to have a certain amount of out of roundness. You can't change this but it would give you an explanation for your vibration. Along with the normal belt oscillation that I mentioned above.
.
You can easily let some oil out the drain plug to correct the oil level by unscrewing it with your fingers and holding it in place to slowly let some oil out, and then screw it right back in. Metal seal rings can actually be reused many times with no issues. But unless it is drastically overfilled, oil level or differing oil chemistry cannot be "felt" as a vibration.

Use a syringe

[frog13]

Easier solution , yes .

[sendler2112]

I don't have a syringe and my wrench is still laying on the floor next to the drain bucket.

[frog13]

Walmart sells them , they're actually for 2 cycle engines but have appropriate ounce markings as well as ratios.