How is it supposed to feel at high speeds?

[zombie]

 don't ride any faster than you want to crash. Serious!

If it is pinching then the cage is broken, and a piece of steel is floating around in there. If it grabs wrong it will jam, and blow the rest of the cage apart causing the wheel to attempt a complete stop while shifting its center.

Yours may not be in that state but from your description what I state is correct. You don't have to get the Kymco bearing... Pull one out, and it is clearly marked as to it's dimensions. ANY good auto parts store will stock an exact replacement. Just tell them you don't know what it is from. Your boss needs it whatever.... They always rely on the F'n computer instead of their brains today.
Look for the Old Guy that has been there done that. Kids don't know sh** today.

[hypophthalmus]

To follow up with the rear wheel thing, it seems to be spinning evenly now. I guess it just needed to be taken apart and reassembled.

[zombie]

Well that's a step in the right direction.

[hypophthalmus]

Some questions:
I finally got started with replacing my bearings (though I hit a snag where the local store doesn't sell metric bearings). When I roll them now that they're out of the wheel though, they roll smoothly. Can anyone make sense of that?

Also, I think my rear brake feels firmer. I did push in the piston because I accidentally hit the brakes when they weren't installed. But I would expect them to return to how they were before. The brake performance before and after otherwise seem normal. Can anyone make sense of that one as well?

[hypophthalmus]

Another thing, I noticed that the front brake pad (at least one of them) is unevenly worn. I assumed this was related to the wheel bearing, but perhaps one of the brake pistons is sticking?

[BettinANDlosing]

Aside from rolling smoothly the front wheel bearings should have no side play. On any older scooter with front and rear disc brakes, they will have different pressure. Uneven pad wear is not normal, sometimes one pass itself is worn thinner, but they should be even.

[hypophthalmus]

I wouldn't think it strange for the front and rear brakes to have different firmness. What's weird is that the rear brake got firmer after I finished changing the rear tire.

I assumed that the pad wearing unevenly is abnormal, I'm just wondering if the bearings were a likely cause. I guess I might as well disassemble/lubricate the brakes anyways though.

[hypophthalmus]

So I got new bearings and installed them. They seem generally higher friction than the OEM bearings. Not a single pop per rotation like the last ones, but evenly rough with lots of little bumps. Is this normal for some bearings? Should I be concerned?

[TLRam1]

Hard to determine what you mean with your description, new bearings should be smooth but might be tighter as the tolerance is close, the bearings you removed could be looser and rotate easier because of wear. Hard for me to follow what you are saying.

[BettinANDlosing]

How did you tap them in? Hitting the outer race? Maybe they were damaged during install. If should not feel rough and with a good spin be able to coast at least a few revolutions.

[hypophthalmus]

I hit the outer race with a socket and hammer. I'm not sure how they could have been damaged.
It feels notchy. But unlike my last bearings with one notch per revolution, there's a bunch of evenly distributed notches.

[hypophthalmus]

Well, I contacted the bearing manufacturer. They agreed that it didn't sound right and sent new ones. When I went to replace them though... they felt smooth.

I inspected the brake pads more carefully and indeed both front pads are a few millimeters thinner on the same side. Could this be related to the bike shaking at speed?

[hypophthalmus]

Also, when I took out the pads and squeezed the brakes, only one of the pistons came out unless I held it down with a clamp. Is this normal or maybe related to the uneven brake wear?

[hypophthalmus]

Also also, when I apply my brakes very lightly, I hear them skipping sometimes. My rotor, axle, and wheel runout seemed fine when I tested them. Could this be related to the brakes themselves somehow?