OK this may make for interesting conversation. Now bear in mind this is not about which tire is more trad or more not trad it is a technical question. Feel free to add different rim widths and effects. But I would like an answer to my question as well. This could be a learning experience for everyone and maybe help someone besides me. Now for my question. I am trying to determine a tire size for a project I am currently working on. I am not seeking information for myself on a bias ply tire, that is easy for me. Metrics after all these years on the other hand I find a little difficult. I want to find a radial that will stand strait up on a 5.5" rim. IE little to no bulge. I am thinking that a 190x65x15 will work, or the same size in a 70 series tire. What I don't want is a tire that is too narrow and looks like a dune buggy. Can someone confirm this? P190x65x15? Help me out please? Like I said other rim widths and tire sizes are welcome as well.
Any of the smaller sizes the VW guys use should look good. 155 to 185. Some have a squarer profile than others
https://www.tacomaworld.com/tirecalc I really like this tire size calculator, it's all based on radials. If anyone has a good bias to radial conversion it would be helpful. Here's a comparison of size ****** is looking at and a 155 VW style tire. I think they are 80 ratio, haven't looked at them recently. Best to look at some wheel tire packages with known rim width and tread width, see how sidewall bulge compares to the look you're after. I also use the tire rack website to verify the tire size is even available or if it's ridiculously priced. https://www.tirerack.com/tires/sizes/results.jsp?diameter=15
No bulge in the sidewall = a section width that equals the rim size. So look for a tire that has a 5.5" section width.
******, a 195/65r15 has a section width of 7.9" an a tread width of about 7.5". Max recommended wheel width is 7". So, no way a 195 will sit straight up on a 5.5" rim. A 155 to 165 will be about the best you can do.
I know Tire height and tire width play a part in sidewall bulge , but tire brand does as well . cooper cobras always have a decent bulge as do Goodyears . anyways just something else to keep in mind .
This is one that I was considering for the front of my A, 25" tall. https://www.prioritytire.com/thunde...E4yZ_ysi6CldgjzlTPcho9E9UF93LMmBoCYJoQAvD_BwE
Running these on the girlfriends car https://www.performanceplustire.com...-whitewall/ty:Tire:ts:tiresizeshort-185-80-15
I run a 185R15 (185/80R15 is what it translates to, but sometimes doesn't have the /80 used in the size) on front of my 52 GMC; see avatar pic. You can also get a 165R15 or 155R15 that would be closer to the width you want.
So, I got a question, too. When they list the revolutions per mile, is that based on the diameter of the tire unloaded, or do they figure it based on the distance from the center of the axle to the ground with a load on it, since all tires squat a little loaded?
It shouldn't make any difference. Turns per mile is based on the cir***ference of the tire, it's a simple calculation. Now I'll grant that small variations in the cir***ference can be introduced by changes in rim width and tire pressure but the local distortion where the tire meets the road won't change the total length measurement. If you have an 80 inch (or whatever it is) cir***ference, the load can't change that. ******, this is what you need to do. I do think that using a higher aspect ratio will help. The fly in the ointment may be will the tire's load capabilities be up to the task? And I don't think you'll ever completely eliminate the 'radial bulge' but this will minimize it.
My Falcon has 195/60-15's on 15 x 7" wheels. The don't have much in the way of sidewall bulge, save for the inbuilt curvature of a radial sidewall. I do need to be careful not to hit the wheel lip on curbs. A narrower wheel would make the sidewall appear more curved.
Remember, radials are described using section width, not tread width. The three digit number in millimeters is how wide the casing is at the widest point, or the fattest part of the bulge. If you want the sidewalls straight up, you might want to generate the possible number by adding 1/2" to the wheel width (where the bead sits), to get the lip width, and go from there. If you have a 5-1/2" wheel, figure for 6" section width, which is 152.4 (rounds to 155), as has been mentioned. The percentage number that follows indicates the height, as a percentage of the section width, times two, plus the wheel.
One big obstacle to doing a bias-ply to radial size comparison is sidewall height, or aspect ratio for the radial. In my observation, an whole lot of bias-ply tires, if measured using the modern methodology, would have an aspect ratio over 90%. In the case of the venerable 6.70-15, in the modern nomenclature it would be a 170/91-15. A 5.60-15 (5.96" actual) would be a 142/91-15. Making an near-square radial is a difficult task, and especially so if it is a small one.
Hope this note is not too far off the mark? The tire look,well we all have likes an dislikes. I like to say why my thoughts;; Tires are made for a rim size,but really for high performance,like racing of any type=can be just as well for hard street running. I like the look of a wider rim then the tires tread= Less wiggly side to side,an better bite. The other way around;more tread then rim,will let a tire move off center from rim too much=feels like driving in Jello. So,no I don't care much for the so called straight up side wall look. I think most of us,understand the more tread on road=more bite! So,using the widest commonly available tire that match's the year engine in a hotrod,or with in a few years more/newer then engine=As it should be! Anytime I see OHV V8 in a hotrod*,if it has skinny flathead V8 tires,I think of who ever did that,as foolish. Hope that's not too blunt,I'd like to see that now trendy skinny tire **** stop on OHV V8 powered rods.
And that's the big problem. As Gimpy says, the 'old style' bias ply tires had really 'tall' aspect ratios and there simply isn't any modern equivalent in a radial with the possible exception of some truck tires but those are all too big. 'Back in the day' the guys generally used small Pirelli or Michelin radials but those were built as upgrades for bias ply tires used on VWs or import sports cars. I'll bet you can still get those, but they're no doubt 'specialty' tires these days with the attendant 'special' price....
The Diamondback Auburns are a pretty decent look. The problem is the cost. However bias plies are stupid money now. https://www.performanceplustire.com...wNMgHOv5w2ddhjOlzY9PSTz9qjbwSmXRoClyAQAvD_BwE
The other thing to look at in terms of aspect ratio, is what is the tire recommended for? Usually the 80 of 90% rations are designed as light trucks and therefore have very stiff sidewalls (and thus ride). Lower inflation helps, but builds heat. The whole world is a trade-off!!!
Reading between the lines, I believe you are saying that you want a radial tire that emulates the appearance of a bias-ply tire. Since even a bias-ply tire has some "bulge" and none of them will ever be ruler-straight like an oxcart wheel, I think it's possible for you to get the look you are after in a radial. In general, the taller and shorter aspect numbers in the ratio will both "bulge" the same amount....... but the taller sidewall of the two will average that bulge out over a greater span to give the illusion of being flatter. I think we all instinctively know this but are saying it in different ways. In your situation, you might want to first decide what tire height (diameter) is best for the cir***stance. So, the basic math goes like this for a 190x65-15 tire....... 190mm x .65mm = 123.5mm, x 2 for both top and bottom of tire, = 247mm, divide by 25.4mm (which is an inch) = 9 3/4" rounded, + 15" wheel = 24 3/4" overall tire height. You can quickly play around on one of those "tire calculator" links and compare slightly different aspect ratios and see how much your target tire height is affected. Compare 190x65-15 to 185x65-15, or 190x70-15 for examples. Of course, your choice of tire brand won't be available in every possible aspect size so you may have to settle on whatever is closest.
Thanks! That makes sense. I guess I was thinking of cir***ference calculated by radius to the ground. Sometimes I overthink things, sometimes I don't think things enough, sometimes I get a headache and quit thinking...
No actually I am not in the least trying to emulate a bias ply tire. I am screwing one together that the front track width is a little wide for the fenders. The wheels I am planning on using are 5.5" and enough back space to keep the wheel lip just inside the front fender. If I go with a tire that is too wide even with the wheel just inside the fender the tire is going to stick out. I am not leaning toward the '80s street rodder look so the tire sticking out past the fender is not optimal. If I was running a bias ply tire it would be easier a 5.50 or a 6.00x15 would work fine. But radial tires are harder for me to guess. If I got too fat with the radial it sticks out and if I go too narrow it gets that dune buggy look. I guess what I am looking for is a tread width of about 5-6". A 6" thread width would only be about a quarter inch on a side and a 5" would be the same only in the opposite direction.
Beano, you might scroll through this old thread and it might give you some clues as to what will work for you. HRP BIG & LITTLE
OK this is just an update. I read everything, looked at everything and finally landed on 185x65x15. I spent some time on the computer at the local garage searching one of the larger distributors in KCMO. The most common tire size was the 65 series tire. They had 70 and 80 series tires. very few choices for either in a 185 and 2 pages of 65 series tire in a 185. With one exception the 70 and 80 series tires were 8 ply. Anyway all that aside, the tires stand up pretty good on my 5.5" wheels. Anyway just so that you all know that your time was not ill spent. Note if anyone is up on Ansen serial numbers these wheels are stamped 542 A016. Not that it makes much difference.
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