I noticed a bulge on the side of a tire so went back to Discount Tire. Was told it was part of the construction process where the forms meet or such. Sure enough, a 2 to 3 inch wide bulge can be felt on each of my tires in the same place. Yokohama Geolander AT, 265/75/16. The bulge is right after the A/T on each tire. Just wondering if anybody else has heard of this. I've never noticed it on other tires.

Personally, I wouldn't be comfortable with a bulge in the sidewall. Had that happen to me years back. I'd hit something and there was air leaking into the body of the tire. Wound up blowing out the sidewall..

Is it a bulge (i.e. a big pimple), or just a an area of overlap

Sounds like your tires really like your 3rd gen.

You do know rubbing on stuff may cause bulging, right?

My General tires do have a very slight indentation on the sidewalls, even when brand-new. None have blown out in the 7 or so years I've had them so I'm going to make an educated guess it's just the design of the steel belts.

Since it's in the same place on every tire, chalking it up to how the tires are made.
Bulge is more than a pimple, more like a raised area about 3 inches across and maybe 1/8 high. Just kind of bugs me. If any of you have the same Yokohama tires would be interested if you can feel raised areas near the A/T on the sidewalls.

Copied the following from TireRack website:
Sidewall Indentations / Undulations
Sidewall indentation
Fig. A: Vertical indentation on sidewall from rim to tread.

A common byproduct of radial tire construction, sidewall indentations/undulations are more noticeable in tires with taller sidewalls or operate at higher inflation pressures. Fortunately sidewall indentations are a cosmetic condition that does not affect the performance of the tires.

Tire casings are reinforced by multiple fabric cords encased side-by-side in a thin sheet of rubber. Radial ply tires feature one or more layers of cord (depending on the tire's required strength) that run parallel to each other from bead to bead (with each individual cord running up the sidewall, across the tread and down the other sidewall). Because of their "straight across" radial orientation, the overlaps where the sidewall cords are lap-spliced may cause indentations.

When the tire is being cured, it is pressed against its metal mold. However when the tire is mounted on a wheel and inflated to operating air pressures, it is free to expand. These overlapping splices may create slight indentations since the stretching capacity of the lap-splices is slightly less than the rest of the body ply. In reality, the splices are the most reinforced area of the tire's sidewall.

Since radial tires feature steel cord reinforcing belts under their treads to keep them flat, indentations only appears on the sidewalls.

I vé had Yokohama geolanders At's for almost two years now and no bulges etc. Being great in snow was my reasoning for the purchase. Mine are 265 70 r16 though and have been great so far.

Good pictures of your issue would be great, here.

This is normal.


This is not. Almost always a result of an impact.

I personally wouldn't be comfortable driving with tired with bulges. I just paid nearly $1000 for new tires from Discount Tire and if they said bulges were something to expect I'd say a refund is something I'll expect.

I have the same (1st picture Riceye posted) on all 4 tires on Cooper Discoverer AT3, and I also went to Discount tire to inquire and got the same reply. It is been 3 years and it looks the same.

That's how my Generals are. Again, 7+ years of daily driving. I also forgot to mention how relatively low the road force numbers were when I balanced them.

Ouch, definitely impact, probably a deep pothole at a fairly high rate of speed. Tire is FUBAR

Here is a pix. Only noticeable when lit from the side like this, or felt with hand. it's definitely a bulge instead of indentation. Reading that on taller tire sizes like this Yokohama Geolander 265/75R/16, such construction results might be normal. Since it's the same for all 4 tires I don't think I have much of a case to replace so I'll keep riding.

Pretty normal occurrence and likely part of manufacturing process because its in the same spot on all 4 tires