'bumps' in sidewall - Goodyear Marathon

[ericwarren]

We just purchased a 2006 19' int'l and noticed today some lumps or bumps or whatever you would like to call them on the sidewall of one tire.
Not sure if this is normal but thought i'd post a pic or two and ask your opinions.
thanks

[ericwarren]

ok..that didnt work...lets see if i can figure out how to post pics

[ericwarren]

I think i figured it out!

[2airishuman]

hi eric

BIG thanks for posting photos....

we can't resize or open your pix in a new window, so good resolution is an issue...

the pic on the right looks like a NORMAL belt overlap indentation...

see this thread and the LINKS in my post #9...

http://www.airforums.com/forums/f438...-do-44306.html

your photo on the left looks more troublesome, as a bulge...

u can change tire pressures (go from 30 psi to 70) with the wheel OFF the trailer....

IF the bulge changes with pressure, OR when pressed on with a finger it flattens (fluctuations) ....

THAT IS BAD, get a new tire.

depending on the gy dealer u may have a debate about defect vs damage as the cause...

here are some pics of my factory replaced tire with fluctuant bulges

http://www.airforums.com/forums/show...8&postcount=79

as the tire rack link above shows these bulges are bad, but depressions are ok....

cheers
2air'

[Lumatic]

Ditto on normal belt overlap. It's hard to make out the photo on the left.

[DEITZ645]

Eric,
I can't really tell from the fist picture, but it looks like the trailer tire is pretty hard against a wheel chalk. Does the tire exhibit the same bulge in the same place when the tire is not against the wheel chalk???

[ericwarren]

good question....i don't know. i put the chock in after the trailer was stationary.
i can remove it and check.
would this be a typical cause?

[overlander63]

The bulge being from a wheel chock is normal, a bulge there all by itself is a bad thing.
Indents along the sidewall are the areas the steel belts that reinforce the tread area are attached to one another, and is completely normal. Not so a bulge. A bulge in any area of the sidewall of a tire tat has no load on it is at the beginning stage of a belt separation, and eventually could cause the tread to detach from the casing of the tire.

[DEITZ645]

Eric,
Might I suggest removing the chalk. Mark the bulge with masking tape or something, and then move the tailer a little to see if the bulge moves or disappears. You could also jack the trailer up under the axle to see if the bulge disappears with no load on it.

[94Tri]

It looks like a bulge on the left pic to me. If so, I believe I would replace ASAP to avoid endangering any precious aluminum. The previous post recommending marking the spot and moving the tire to see what it does seems to be an excellent idea.

[SRW]

Originally Posted by 2airishuman

hi eric

BIG thanks for posting photos....

we can't resize or open your pix in a new window, so good resolution is an issue...

the pic on the right looks like a NORMAL belt overlap indentation...

see this thread and the LINKS in my post #9...

http://www.airforums.com/forums/f438...-do-44306.html

your photo on the left looks more troublesome, as a bulge...

u can change tire pressures (go from 30 psi to 70) with the wheel OFF the trailer....

IF the bulge changes with pressure, OR when pressed on with a finger it flattens (fluctuations) ....

THAT IS BAD, get a new tire.

depending on the gy dealer u may have a debate about defect vs damage as the cause...

here are some pics of my factory replaced tire with fluctuant bulges

http://www.airforums.com/forums/show...8&postcount=79

as the tire rack link above shows these bulges are bad, but depressions are ok....

cheers
2air'

I have the same indents (or undulations) on two of my 2 year old Marathons, and I am happy to learn that such features are normal on radial tires.

Although I am concerned that the indents have appeared only recently and at multiple places around the circumference of the tires.

Worth noting that there is nothing that looks like a blister or bulge on any of the tires.

Interesting that the guy I spoke with at the local Goodyear had no idea what I was talking about.

Thanks for the info.

SRW

[azfiredog300]

Those indentations are actually caused by damage done to the rubber at the bead while the tire is being put on the rim. Generally nothing to worry about because the bead still holds firmly in place. If the worry is too great usually the dealer will replace due to it being improper mounting practice.

[Janets Husband]

Please read this article.
Tire Tech Information - Sidewall Indentations, Undulations and Protrusions

[overlander63]

Generally, indents are nothing to worry about, it is where the steel belts are attached to each other. Bulges, on the other hand, could be the beginning of separation. Replacement would be a good idea.

[SRW]

Originally Posted by azfiredog300

Those indentations are actually caused by damage done to the rubber at the bead while the tire is being put on the rim. Generally nothing to worry about because the bead still holds firmly in place. If the worry is too great usually the dealer will replace due to it being improper mounting practice.

Your comment puts a different slant on the issue of indents versus the Tire Tech report referenced by other.

The report states "......the overlap where the sidewall cords are lap-spliced may sometimes cause a slight indentation", and offers no reference to improper tire mounting.

I think that I will tow the trailer to a Goodyear store and have them look at the tires.

SRW

[TBRich]

Our Marathons have the same indentations at 2 or 3 points around the tire, and from what I understand (as stated by others here) this is normal thing resulting from the manufacturing process of overlapping belts. When I first noticed them I was concerned, but after researching it, I am no longer worried about them. Bulges, however, are a different story, and the tire should be replaced.