everytime i measure my current wheels that the previous owner had it comes up to 19.5", so is this size considered 19". Lol i really dont know..

 

hey ... i believe the size of the tire is measured from lip to lip on the inside of the wheel (you have to take the wheel off to measure that) so the outside is always like an inch and a half bigger ... so you prob have 18s ... i think that's how it works ... i might be wrong... guys please feel free to correct me

 

yeah i was thinking that something is not right because there is no .5

 

The wheel diameter is measured at the bead seat, not at the edge of the lip (widest point). Without a huge caliper, it difficult for the average person to measure the diameter accurately. Most of the time, the diam, width and offset are stamped on the back side of the wheel somewhere.

 

Shopping for 19.5 inch tires is going to be tough. Good luck.

 

this pic should help


The wheel diameter is the "nominal rim diameter" measured from the bead seat not the outer edge of the metal.

 

Wow i have no idea what that picture is..

 

I think it is part of the females anatomy....not sure though

 

It's a slice through the tire and wheel from top to bottom. You're not much of a visual person I take it....

 

^^ The pic shows a cross section of a tire on a wheel, and everything about measuring a tire, but nothing about measuring the wheel's overall diameter (which I believe was the question Gag83 originally asks).

--Spike

 

wow i still dont see it?!!??!

 

Well spike...see that measurement titled "nominal rim diameter"? It's at the right and encompasses the entire wheel height. Now, see that part of the rim that is behind it where the tire would seat so as to not lose air? That is the "seat" and seems to be the area that is confusing both you and the OP. The wheel isn't measured at the farthestmost edge of the outside of the rim. It is measured at the "seat", where the "rubber meets the rim" as it were.

I was trying to answer the question but probably could have used a different graphic since no one apparently saw what I was saying. My bad.

 

The black is the tire sliced. The gray is the wheel. I'm guessing you measured the wheel from the lowest or highest part of the "gray" at the right. The measurement is from where the black (tire) meets the gray (wheel). I'll try and find something less obtuse.

Like the size of the effing tire that was on the wheel....k kidding that was harsh.

 

The “nominal rim diameter” is actually what Gag83 is measuring on his wheels, and that is why he is recording a high value past the actual height of the wheel.

Notice that the picture you put up does not have a label identifying the “bead-seat.” The “bead-seat” is actually a transition area, and it may not be identical (as to height and angle) on the outer and inner rim of the wheel. In fact, the bead-seat wall on the wheel is often more vertically orientated on the wheel’s inner rim. That’s why Dave mentions: “Without a huge caliper, it difficult for the average person to measure the diameter accurately.”

It’s unlikely that someone can simply use a tape measure or a simple yardstick ruler and hope to accurately measure a wheels true diameter (as it applies to the proper tire height).

--Spike

 

I'm not in disagreement with you. I was merey pointing out where his measurement may have been innacurate. We're on the same page bro. I assumed the OP saw what I was posting.

OP, check the tire, it will tell you the wheel diameter.

 

And, the bead seat varies from wheel to wheel even in wheel size you bastage (as in grabs more on the vertical/grabs on the horizontal). So a better measure would be "Hey, dude...what size tires would you put on this rim? and please don't stretch those small tires over my spokes"