iGeorge

I have the 18" alloy wheels for my 2012 e550 4m; Mercedes part number 212 401 3602 88. This past week my mechanic showed me a flat spot on the wheel between the spokes; he says they aren't bad enough to damage the ride, and it didn't affect the balance, so I shouldn't panic. But I'd like to ask some questions:

In the forum members experience, are these flat spots common?
In the forum members experience, are these wheel tolerant of the presses used by rim repair companies.
Should I consider repairing or replacing the wheel which has the flat spot?

Sunnyslope48

Is the flat spot on the mounting surface of the tire? And how big is this flat spot? Can you post a picture of this? If it isn't on the mounting surface and you have no balance problems, I wouldn't worry about it. Of course, if you are one of those that just needs things to be perfect, by all means repair or replace it.

belarus27

never even heard of this before.. what is a flat spot? can anyone enlighten me plz

Uda880

I think the only times I've ever heard flat spots being talked about was when members park their cars for prolonged periods of time, and the tires begin to deform and create a noted indentation on the contact patch with the road/garage surface. It usually evens out after some driving.

KEY08

This flat spot is on the wheel? Never heard of this, ever.

belarus27

thank you..... i wonder how long it has to be park in case for it to happen.... years? lol

Uda880

Some times even months, or weeks. Good example is if we parked our cars when the temperatures change and tire pressure lowers, all while entirely parked due to some business or life circumstance, when the car is driven again, the ride will feel uneven and bumpy for the first few miles.

Although in the OP's case, I actually think this may be an actual manufacturing problem on one of the wheels? But if it's balancing out and not losing air pressure, I wouldn't worry about it.

Trelos

OP, By flat spots do you mean bent rims?

KEY08

Bent rims are usually on the back side of the wheel in the barrel where it's weakest. Not the face typically.

cetialpha5

I've had my rims fixed before. The guy says that OE rims are easy to bend back and they are fine afterwards, aftermarket ones are sometimes weaker and don't hold up as well. The flat spot is probably from hitting a pothole or curb. And if you see it on the outside, you should check the inside, probably there too.

thenew3

Flat spot on tires can happen overnight. Depending on the compound and design of the tire.

If I don't drive my car for 2 to 3 days, I will get slight vibration in front end for the first couple of miles due to flat spotting in the tire.

Flat spotting in the wheel is usually a manufacturing defect or you hit something hard enough to cause the wheel to bend.

It happened to me once when I hit a 2x4 piece of wood on the highway (fell off a truck in front of me and I didn't have enough time to dodge it).

It bent the rim and caused a "flat" looking spot in it and could be felt in the steering wheel as severe vibrations. Tire was not damaged, so I had to have the rim replaced.

belarus27

at first i thought it was something similar to this , but i guess its a different thing

thenew3

That looks like you hit something, there's some paint scrapped off on the edge of the rim as well.
That looks like it should be fixed or replaced ASAP.

belarus27

NO NO , its just a pic from the internet , i thought thats what *flat spot* look like... i was wrong.

(i had bent wheels like that in the past tho)

thenew3

Ok that looks similar to what happened to my wheel after I ran over that 2x4 at 80mph.

The tire didn't blow out or leak but was getting violent shakes in the front end.

iGeorge

I can't show the flat spot unfortunately; the tires were being replaced and before the car came off the lift, the mechanic spun the wheels to show me the flat spot while watching the edge of the rim spin by.

iGeorge

Yes, bent rim, seen from the inside aspect of the rim while I was standing under the car; the car was up on a lift.

iGeorge

It not nearly as bad as that photo, but yes, the same type of thing. Wow, I guess this isn't an uncommon occurrence! Thank you all so much for the replies! I'll look to see about repairing the rim.

belarus27

whete you located , i could hook you up with a wheel repair guy , would cost you only 80 bucks.

iGeorge

PM sent, thanks!

cx876

can you send me the info too ?
I'm in SF and I believe two of my rims are bent slightly

belarus27

PM SENT

MBNUT1

In the morning on my way to work I get what could best be described as a beat frequency resonance It seems to improve as I drive more. Did your tire flat spotting make a similar vibration?

thenew3

Sounds about right. If it goes away after a few miles (when tires warm up) then it's most likely flat spotting in the tire.