I am getting ready to order some wire wheels for my '32 highboy roadster project. It has a 46" front beam axle with Willwood disks, and a 56" wide mount to mount rear axle. I have already bought tires 6.70-15's and 8.20-15's My wheel size choices are: 15 x 4.5 with 1.75" backspace 15 x 5 with 2" Backspace 15 x 6 with 3" Backspace 15 x 7 with 3.5" or 4" backspace What sizes would you run? what would look the best with the tires ? (especially in the front) My original thought was 4.5" in the front and 6" in the back, but now i'm not sure if I should run a little bit wider wheel to cover more of the brake in front so it looks better head-on ? it looks like a 1.75" backspace would put the edge of the wheel right about the middle of the rotor. Not bad I guess ? Anybody running 6.70-15's in the front ? what size rim did you go with?
Well, 'back in the day' most OEMs that used 6.70 tires usually put them on a 5" or occasionally a 5.5" wheel...
Most discs make the wheel sit out too far as not having proper scrub radius. >> Scrub radius somewhat defined/described, is: The imaginary line through the king pin down to the pavement, and that line needs to be under the tire tread footprint, not beyond the inside edge of the tire tread. So, adding backspace is how to get that wheel back inwards more for a workable scrub radius. But that can interfere with the rim hitting the caliper. This is tough stuff to try to figure out if you don't have different wheels there to try, to see if the caliper will hit. I run 670-15 bias fronts on mid 60s VW bug wheel rims welded to 40 Ford wheel centers. The bug rim is maybe 4" or 4.5" width. (40 drum brakes)....rears are 760-15 on Olds 5.5" or 6" wide rims .
Cool, thanks for the pictures and info ! I know most people go with the smaller tires on the front, but for some reason I have always gravitated towards a bit taller rubber on the front of a highboy '32. On model A's it doesn't seem to mater as much to me, but 32's have a tall enough side, I just like it. My biggest fear is that the 8.20's on the back won't be tall enough looking! The only reason I went with 15's over 16's, is I don't want to run tubes, and I wanted the bias look radial blackwalls. I'm going with black painted wheels to help visually blur the wheel/tire line to try to hide the fact they are only 15" diameter!
If you can put on a wheel and look to see the scrub about 6" under the outer rim. Remember the kingpin angle should hit the ground at the center of the tire.
What build era is the car? If it has any kind of overhead engine, meaning the rodder wanted the newest stuff, 15" was what they mostly ran coming into the 50s decade. Tiny fronts were not the norm if you cared to look at old genuine photos of typical street driven rods ''all over' the country. There are also photos showing that some ran equal size tires on F&R on fenderless cars. and others ran tires very close to same diameter, too.
The tire sizes you mentioned in your first post indicate bias ply tires. However, your quote above says “bias look radial blackwalls “. Please clarify your tire construction type front and rear as it is a definite no-no to mix bias ply with radials on a vehicle.
Well, at the risk of being an outcast, the car isn't really going for any certain decade. It is a Brookville body with all stock hinges, latches, cowl vent, etc., original peaked shell, original insert, original 4 piece hood, stock type 2" chopped windshield, Lebarron Boney 2" chopped top in tan with the gypsy panel , full Lebarron Boney stock type interior but in burgundy vinyl, It will be a highboy in gloss black with blackwall tires, and gloss black 15" wire wheels with original 32 caps, no trim rings. I really like the look of 40's / early 50's built cars, BUT I wanted a decent HP small block, a Tremec TKO, and disk brakes on a chrome front end. The chassis will have stock horns front & rear, and a stock style gas tank. The engine is a ZZ4(still looking for old looking valve cover options, or run adapters to some old cal customs I have) I live in the middle of nowhere,by a bunch of hills & canyons, and want a car that is performance minded enough to be fun, reliable enough to do lots of highway driving, strong enough to abuse, safe enough to panic stop or go down a long mountain road, and still have a certain "look". I also have a set of straight spoke un-polished Torque thrusts in 15x5 and 15x7 , and a 3" chopped windshield, and few different sets of headlights, if I want to change it up once in awhile. The tires are the Coker "Bias-look" Radials, that look like Bias ply's , but are of Radial Construction. I went with 15's because the 16's require tubes, and I didn't want to mess with that. I went with 6.70's in the front because I like the taller look of 16's and I am going with no trim rings and black wheels to visually distract from the smaller diameter of my wheels. It's "traditionally minded", or "traditionally based" ....... I know it isn't really "correct" to any era, and lets face it : disk brakes and five speeds are a no-no to some people ! but not me ! I have owned "correct" cars in the past and had fun experiences with bias ply tires, drum brakes (even mechanical) and weak transmissions. Some people might even call my new car a "Street Rod" (gasp!) but it's a Hot Rod to me, and what I want, so....
Well, I just spent a few hours mocking stuff up and researching scrub radius, and damn ! my dreams of wire wheels might be out the window. None of the ones I have found that would take a stock Ford cap have any kind of deep enough backspace. My tallish tires help a bit, but ? I sure see a lot of cars running disk brakes & wire wheels and it makes me wonder if they drive bad/good/too many variables to tell ?The only wheels I have to put on to scope things out were my tire-less 15x5 Torque thrusts that have a 2.75" backspace and it's barely what I would call adequate in the scrub department.(from what I am reading? ) If I did a steel "gennie" style steel wheel, I could do 15x6 with a 3.75" backspace , but would a 6" wide front wheel with 6.70-15's look too wide on the front of a highboy? Just go with 5" wires with a 2" backspace & hope for the best? 6" with 3" backspace wires ? argh !!!!!
I am running a wheel vintique 5" wheel on my full fendered 32 with a 155 tall bfg. I wouldn't running anything wider. I know this probably doesn't help a bit!
On a skinny tread tire like a Firestone 670-15, that imaginary kingpin line would be fine if it was at least somewhat under the tread. It's not supposed to intersect the ground at dead center of the tread width. You said earlier that you prefer a bigger tire on the front, compared with the modern trend of always using a very tiny tire these days...so it might look OK to you. When you mocked up that TT, did you try to imagine what clearance you would have at the caliper if you went with the custom-ordered deeper backspace? I'd be concerned about that because returning wheels gets costly Would a pic of a Firestone B/W 670-15 bias tire mounted on a chevy 6" wide steel wheel help? Unfortunately it's not on a car, it's on my car trailer. It would only show how a narrow treaded tire looks like on a 6" wheel rim.
That picture would help, thanks ! especially if its from the end enough to see what kind of bulge the tire has.
Thank you very much for taking the time to post the pictures, that gives me a really good idea on what I'm dealing with ! Thanks to everybody else too ! Id hate to buy the wrong wheels, that gets expensive in a hurry ! Still doing a lot of thinking, measuring, & head scratching ! If the car was done, it would make life way easier, but I just ordered the frame, the body is on a pallet and I have half the front end assembled on my shop floor.....
I’ve got a “similar” 32. Dearborn Deuce, channeled. You’ll need to work on the stance/look to fit your taste. I’m running 5.60’s on the front, and with the weight of the Yblock up there, I wish they were a little more tire. So I like the 6.70’s. But until you’re together, don’t get ahead of yourself. Go to the local elcheapo used tire guy and buy some cheap rims, maybe even with bald tires about the right height. You can use them as rollers for the build. Unless you’re an expert, which I’m not, trying to “imagine” the finished product is tough. I’m running the Coker bias look radials, 5.60 15, 8.20 15 and love them. Store them in a cool dark place till you’re in the final stages. You can use jackstands and plywood disc to lean the tire against before you commit to pricey wheels. It’s your car, make yourself happy.
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