resonating back wheel?

[PCX-1050]

Hi, I’m new here… signed up because of a problem with my PCX 125 commuter.
The problem is that when riding 60 km/h, something starts to resonate. I feel it in my feet, and the frequency goes up when I ride faster. It feels like riding with a screw in the back tire.
I went to my local honda shop, and they took a look at both pulleys, nothing wrong. They said it’s problably the bearings in the final drive, which cost me a lot of money.. So I picked it up and decided to try it myself. My PCX125 is from ’11 and has 7000 km on the clock.
So yesterday I started, and right away I noticed a really small play in the back axle, the coupling side… It’s really small, but it’s there. Both pulley axle and back wheel axle have no play whatsoever. Is that ok?

Forward axle, no play:



Back wheel axle, also no play:



Coupling axle, small play:




Any advice? Tomorrow I starts stripping the PCX further so that I can open up the final drive.

[gn2]

My advice?
Don't ride at 60kph.

Could it be tyre out of balance?
Did you try moving the wheel (while its all assembled) to check for any free play?
The end of the shaft which you say has some free play is meant to be supported (in a bearing) by the rather substantial A-bracket.

Clutch bearings are well known to fail, they would be first on my list of bearings to check.

[Mel46]

The older models had a problem with the clutch bearing as well. Our 2013 model had the problem. I believe that the 2011 model uses the exact same assembly.

Look at items #18 and 19. (Needle BEARING and radial ball bearing.)
https://www.partzilla.com/catalog/honda ... riven-face

So, while you are tearing your bike down you should look at this, and possibly replace the entire assembly.(Driven Face set ... #8) part # 23205-kwn-640

Here is the page for the 2011 pcs 125.
https://www.partzilla.com/catalog/honda ... riven-face

[easyrider]

In addition to the above, check tire for flat spots, uneven wear etc. Have you hit any bad potholes of late. You should be able to hear a rough bearing if you spin the wheel.

[PCX-1050]

Thanks for all the advice!

An unbalanced tire, or a damaged rim should also be noticable at all speeds? Not only at 60 and up?

Back wheel has no play when assembled. That was the first thing the mechanic checked.

And botch clutch bearings. How do you check them? The needle one moves ok, and the ball one moves ok when i put my finger in it. When I put the clutch back on, both discs that are driven by the belt have some movement...

[easyrider]

An unbalanced tire, or a damaged rim should also be noticable at all speeds? Not only at 60 and up?

Not necessarily true !! Harmonics will change at different RPM's

At 60mph this bike will be humming away and vibration can get more intense and you are getting close to the rev limiter.. but probably you are filtering that out of the equation.

[PCX-1050]

I think i’ll take the back wheel to the tire shop this weekend. To check its balance...

So if it was a shot bearing, i must be hearing that by spinning the wheel / clutch?

[gn2]

When I had knackered clutch bearings it was really noisy when being pushed around with the engine off.

[Mel46]

When ours went bad you could put the bike on the center Stand and spin the back wheel backwards and hear the scraping sound, which turns into a high pitch whine at high speeds , and a growl at low speed after a while. Then it gets worse.

[PCX-1050]

Well my clutch bearings are ok then

[PCX-1050]

problem probably found.

4 of the 6 bearings in the final drive seems to run very raw. like there is sand in them. also the space around 1 layer (red circel) is damaged. so they have been replaced earlier... very strange.

[Mel46]

If that area is a sealed area i have to wonder how sand got into there. Several things come to mind. Do you live in an area where most of the roads are sandy? If the seal is old sand can get into the gearing.

Another question would be whether some previous owner ever pressure washed that bike. Pressure washing a scooter is not a good idea.

It might be a good idea to replace both sets of bearings while you are in there.

[PCX-1050]

Great tip about the pressure washing!

I’ll bring the scooter to the dealer to replace all 6 bearings. I don’t have the tools to extract them.

[PCX-1050]

No sandy roads btw. I’ll think maybe worn bearings. Maybe previous owner drove with low oil in the finale drive.

[easyrider]

When bearings go bad they sound like sand is inside. Get behind it with right size socket and whack it out.

[PCX-1050]

now in search for better bearings.

[springer1]

Nice going taking this on yourself !

[GeorgeSK]

Well you made short work of finding the right tool! Nice job.

I don't suppose that extractor has a goes-in-ta mode? Do you have access to an arbor press?

Good luck as you press onward...

[WhiteNoise]

Excellent photos by the way

[PCX-1050]

Well you made short work of finding the right tool! Nice job.

I don't suppose that extractor has a goes-in-ta mode? Do you have access to an arbor press?

Good luck as you press onward...

I’ve got a press on my work, but can’t get the scooter to it....

Last night I bought better bearings (NGK). I put them in the fridge as they arive. Heat the socket with a heater and hammer them in with my ‘ali express’ bearing-go-in-the-hole set.

I’ll keep you posted