which tire is bigger between 16.9 vs 17.5l

[4tillingdirt]

I am guessing the 17.5l is wider than the 16.9?

 

[RickB]

It is.

 

[1stDeuce]

Actually, if you look up the specs, you'll find that the tread width is almost identical between the two in R4 pattern, with the 16.9 actually being a tiny bit wider in most cases. The "big" difference is that the 16.9 is 2-3" taller than the 17.5L.

I think 16.9 was originally only available as an R1 tire, but it is now available as R4 too.

Both sizes require a 15" rim width.

My guess is that the "L" was for "Low Profile"... ??

 

[RickB]

Actually, if you look up the specs, you'll find that the tread width is almost identical between the two in R4 pattern, with the 16.9 actually being a tiny bit wider in most cases.

I would like to see that in print. It is counter intuitive to believe that a tire with a nominal width of 16.9 inches is wider than one sized as a 17.5. Goodyear, Titan and Firestone tire data books all agree a 17.5 tire is wider than a 16.9.

 

[1stDeuce]

I would like to see that in print. It is counter intuitive to believe that a tire with a nominal width of 16.9 inches is wider than one sized as a 17.5. Goodyear, Titan and Firestone tire data books all agree a 17.5 tire is wider than a 16.9.

I agree, counter intuitive, but here are both tires directly from the Titan catalog. Both are Titan Industrial R-4 8 ply tires:

16.9 shows 17.4" total width


17.5L shows 17.1" total width


Looking at the 6 ply Titan tires, it's even worse, with the 16.9 showing 17.9" tire width, while the 17.5L shows 17.1" tire width!

It appears the higher ply Goodyear tires, with a more R1 style tread, do fit better with the nominal sizes. The 6 or 8 ply Titan tires with standard R4 tread all seem to be opposite what the sizing would lead you to believe.

 

[RickB]

I agree, counter intuitive, but here are both tires directly from the Titan catalog. Both are Titan Industrial R-4 8 ply tires:

16.9 shows 17.4" total width
View attachment 659242

17.5L shows 17.1" total width
View attachment 659243

Looking at the 6 ply Titan tires, it's even worse, with the 16.9 showing 17.9" tire width, while the 17.5L shows 17.1" tire width!

It appears the higher ply Goodyear tires, with a more R1 style tread, do fit better with the nominal sizes. The 6 or 8 ply Titan tires with standard R4 tread all seem to be opposite what the sizing would lead you to believe.

Different Titan data than what I looked at.

 

[1stDeuce]

Ok, so my 16.9's are finally installed. As mentioned above, the installed width (measured to the widest point, which is the sidewall) is very similar between the 16.9 and the 17.5L. I don't have calipers big enough, but both tires hide the rim by roughly 1/2" when viewed from the back.

The big difference is that the actual tread of the 16.9 is noticeable narrower than the 17.5", not just the .6" you might guess by the size designation.

Also interesting is that the 17.5L's have a fairly flat tread profile, while the 16.9's have a more rounded profile. I haven't had them on long enough to figure out what the pro's/cons are in my case. At this point, I don't really see a difference, aside from perhaps a little less thump-a-thump from the lugs as I run down the road. (I'm running the same pressure as I ran in the 17.5L's)

You can see by these two pics that the tread starts inboard of the sidewall bulge by ~3/4" or more. The 17.5L's tread was more parallel with the widest point of the sidewall when installed.


Not as obvious in pics, but to the eye, the tread is very rounded.


17.5L's for comparison. They are un-mounted in this pic, but didn't round out any more than this when mounted/inflated.
Note the slightly different tread? One was 6 ply, one 8ply. The 8 ply was slightly shorter, so the tractor always had an almost imperceptible lean to the left...