Hello: Please forgive my ignorance in these matters. I do not understand the measurements listed for buying rims. Perhaps it has something to do with converting from or to metric?
Currently I have P20575R15 on the front and P23570R15 on the rear. This is on the rubber. I get that. But if I want to buy new rims, (KMC 702 for example) the numbers are totally different. 5 x 115 and 72.6 / or 5 x 139.7 and 108/ or 5 x 150 and 110.5. And I still haven't even started to sort out offset. So a guy from a tire shop dropped in one day (which was very kind of him) and said I could buy the 702 series. He said the 255/40R20 rubber would leave a 10.2 mm space between the tire and the body of the car. The 245/40R20 rubber would leave a space of 15.2 mm between the body of the car and the tire. In either case, I figure that leaves me about half an inch of space between the car and the tire. So my question is, is that normal and more importantly, is that safe?
And that still doesn't help me solve which rims I can buy. I really like the 702s by KMC but I need a narrow rim on the front (more narrow than I even have now) and I'd like wide on the back but the rim would sit so close to the body. I am told that my offset is 4" negative on the rear. Once I get this sorted out, I'll sell my old aluminum mags.
I found a few sites on the net explaining offset and I think I almost get it. Lay a flat piece of bar across the face down rim and measure down to the inside of the rim where the lug nuts go. The highest point from that surface to the flat bar is my offset. Negative or neutral or positive remains a bit confusing but I know that for my front rims, I am hoping to get rims in which the highest point on the inside of my rim is close to flush with the flat bar crossing the rim because when I turn the steering wheel, the tires I have on there now hit my steering rod if I turn too sharp. Even on the passenger side, my tires can touch the frame if I turn too sharp. It seems there is so much to learn in this hobby but I hope to do things once and do them right (safe). Thank you.
I just wrote a very detailed note on how to determine offset, but then I deleted it. Take your car to a reputable tire and wheel shop, tell them exactly what look you want and let them order the correct wheel and tire sizes. If they screw up, then they are responsible to fix it. The 5x is the bolt pattern and has nothing to do with offset. Look in your manual or online to determine your bolt pattern. It's kind of critical for fitment and safety.
If you really want to figure out your offset on your own, I or someone else here would gladly write up the instructions, but then you will probably end up having to buy a second set of wheels when the calculations are screwed up. Personally, I wouldn't change wheel size, maybe just a little taller tire. Those wheels look great on the car.
Warren
-- Edited by wuga on Sunday 12th of November 2017 04:33:48 PM
Hello Wuga: I appreciate that you advise taking it to a reputable place so the measurements are their responsibility. I can't take the car anywhere until after a safety so I guess I'll just wait until the Spring. Wise advise. Thank you.
As for wheel size, I think I am a victim of first love. I saw the KMC 702 series and fell in love with them. I'm not into flash and shiny rims don't excite me. I like the look of this series in black and they only come 20" or bigger and they don't come narrow so I'd have to get a different series for the front. I'm kind of hoping that if I'm patient, something will turn up.
Forgive me if I insult you Jim but you seem to be building a pretty traditional style rod ,correct? The KMC 702 style wheel to me is an SUV wheel?
Cheers,
Chris.
__________________
Buying selling and trading garage toys and big kid stuff.
No insult taken t all. And yes, after researching it rather a lot, I discovered that the 702 series is an SUV rim but since becoming a member I also discovered that we can do what we like (within reason) with our toys. I happen to like the simple look of the 702 series. A minimal amount (5) of flat, wide strips of metal. No gloss. To me that fits nicely within the context of 'rat rod'. In my line of vision, they simply appeal to me. But as I say, I hope I can find something similar in a more narrow rim so that the front and rear will match. Fortunately, Warren opened my eyes to getting a bigger tire for the rear. I do try to keep an open mind and seriously listen to all advise given on this site. tere is a lot of wisdom to be found here I think. Thank you all. I'll post a photo of how the 702 series look on another chopped model A Tudor.
Right click on the photo you want to use, click on 'save photo as'. This will put the photo in your photo album from where you can attach it to your post.
if you make a post you can then edit it
while editing you can add a pic easy - the box to do that will be at the bottom of the page while you're still on the edit screen
to get to the edit screen click in the boxes at the top right of your post - more will get you to edit
most sites the edit feature times out after some time so you might not be able to edit an older post but you will always be able to edit one you just made
Currently I have P20575R15 on the front and P23570R15 on the rear. This is on the rubber. I get that. But if I want to buy new rims, (KMC 702 for example) the numbers are totally different. 5 x 115 and 72.6 / or 5 x 139.7 and 108/ or 5 x 150 and 110.5.
Some of the numbers you don't get are the bolt pattern of the wheel. Here is a conversion chart. Typical old style Ford/Dodge "small" 5-bolt pattern is 4.5 which shows as being 5x114.3. Typical old style Chev/GM "small" 5-bolt pattern is 4 3/4" which shows as being 5x120.7
The first number that preceeds the 'x' is the number of bolts that wheel uses.
If the KMC 702 is marketed for SUV's, I doubt you're going to find anything too narrow although I am unfamiliar with that wheel.
Bolt Pattern Conversion Chart
4 x 4.25" (4 x 108mm)
5 x 5" (5 x 127mm)
5 x 120mm (5 x 4.72")
6 x 5.5" (6 x 139.7mm)
4 x 4.5" (4 x 114.3mm)
5 x 5.5" (5 x 139.7mm)
5 x 130mm (5 x 5.12")
6 x 115mm (6 x 4.52")
4 x 98mm (4 x 3.86")
5 x 6.5" (5 x 165.1mm)
5 x 135mm (5 x 5.3")
6 x 132mm (6 x 5.2")
4 x 100mm (4 x 3.94")
5 x 98mm (5 x 3.86")
5 x 150mm (5 x 5.91")
6 x 135mm (6 x 5.3")
4 x 110mm (4 x 4.33")
5 x 100mm (5 x 3.94")
5 x 155mm (5 x 6.1")
8 x 6.5" (8 x 165.1mm)
5 x 4.25" (5 x 108mm)
5 x 110mm (5 x 4.33")
5 x 205mm (5 x 8.07")
8 x 165mm" (8 x 6.5")
5 x 4.5" (5 x 114.3mm)
5 x 112mm (5 x 4.41")
6 x 4.5" (6 x 114.3mm)
8 x 170mm" (8 x 6.69")
5 x 4.75" (5 x 120.7mm)
5 x 115mm (5 x 4.52")
6 x 5" (6 x 127mm)
8 x 200mm" (8 x 787")
-- Edited by Pete Moss on Monday 13th of November 2017 10:45:56 AM
__________________
Actually, in real racing ... it IS how fast you went.
One other thing you should maybe be aware of ... I have heard that some wheel spacers are illegal in the sense that you can't pass a cert with them so I would assume that would also apply to a car if the MTO where to inspect during a random stop. "I have heard" means I don't know if this is true but it might be worth looking into if your wheel choice will require a spacer to make it fit right.
__________________
Actually, in real racing ... it IS how fast you went.
Once you've loaded the pic you can click on "insert" and you will get a full size image in your post. BTW, I've always had trouble walking in heels like that ... congrats for figuring it out.
Hello again: Well I did a LOT of research searching through rims available on the market. Offset and back spacing being my prime concern, I DID find a few narrow rims for my front end (US Wheels offering an almost perfect series called 'Rat Rod'). Vision, ICW, Motegi and Fast offer rims that might fit my front end as well but none look much like the KMC series (shown above) I was hoping to match. I guess we have to learn to compromise in this field of interest? Oh, and HAPPY NEW YEAR to all !
