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Tire size

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Charles Johns

Donation Time
I am thinking about 205 x 70R - 14 tires on 6" wide rims for the rear of my Series V. Anyone run this setup? Any problems with the stock Alpine rearend and suspension? The rear leaf springs seem very close to the stock steel rims with 13" 70 series tires I have now, and 70 series 14" on wider rims look like they may be too wide. I am amazed how narrow tires were on cars from the 1960's when watching old movies.
 
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Bill Blue

Platinum Level Sponsor
Charles Johns said:
I am thinking about 205 x 70R - 14 tires on 6" wide rims for the rear of my Series V. Anyone run this setup? Any problems with the stock Alpine rearend and suspension? The rear leaf springs seem very close to the stock steel rims with 13" 70 series tires I have now, and 70 series 14" on wider rims look like they may be too wide. I am amazed how narrow tires were on cars from the 1960's when watching old movies.
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My only comment is that I think it is prudent to think ahead a few years when selecting tire/wheel sizes. The hot setup today is likely to be tomorrow's orphen.

Bill
 
C

Charles Johns

Donation Time
The 14" tire is much easier to find than the 13" and in many more shapes/sizes. With so many classic cars running 14" wheels I think tires will be easy to find even a couple of decades down the road. That would make me 96 years old...and still driving. That would be okay with me but highly unlikely. I am no fan of big tubs and extremely wide tires on such a light car. I watched a buddy with extra wide rear tires hydroplane his light Hot Rod at 70 MPH right in front of me. He spun a couple of times, slipped into the grass on an embankment where he actually gained speed. After about 100 feet on the wet grass he hit gravel on the access road, coming to a stop. I ran down to see if he was okay and he said yes...in some very colorful language. I told him he did some good driving to not hit anything, to which he replied, "After the first spin I realized I was just along for the ride and hung on to stay in the car." He did not have seatbelts, but did once back home. I think the roughly 26" tall tires will work if not too wide at about 8".
 
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PROCRAFT

Donation Time
Charles Johns said:
The 14" tire is much easier to find than the 13" and in many more shapes/sizes. With so many classic cars running 14" wheels I think tires will be easy to find even a couple of decades down the road. That would make me 96 years old...and still driving. That would be okay with me but highly unlikely. I am no fan of big tubs and extremely wide tires on such a light car. I watched a buddy with extra wide rear tires hydroplane his light Hot Rod at 70 MPH right in front of me. He spun a couple of times, slipped into the grass on an embankment where he actually gained speed. After about 100 feet on the wet grass he hit gravel on the access road, coming to a stop. I ran down to see if he was okay and he said yes...in some very colorful language. I told him he did some good driving to not hit anything, to which he replied, "After the first spin I realized I was just along for the ride and hung on to stay in the car." He did not have seatbelts, but did once back home. I think the roughly 26" tall tires will work if not too wide at about 8".
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Go to 15" wheels you'll be ahead in the long run maybe 195 50x 15 for a size or.
 
sunalp

sunalp

Diamond Level Sponsor
Good advice on the 15's. They're even getting hard to find. Seems manufacturers drop tires
quickly these days!
 
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Bill Blue

Platinum Level Sponsor
May I suggest looking at newer cars and finding a tire size you like and marrying it. That is essentially what I did, ending up with 185/65-15. Yeah, its an econocar car size but good rubber and not a bad choice for a 'Cruisin Alpine. Udoubtedly not the best choice for a romping - stomping pee bringing Alpine.

Bill
 
Barry

Barry

Diamond Level Sponsor
The horizontal distance between the outside of the rear leaf spring and the inside of the fender lip at the top of the fender arch on a Series Alpine is about 9 inches.

Factory 5.90-13 tires on Series Alpines had a section width of about 6.0 inches and a diameter of about 22.8 inches.

A 205/70-14 tire has a section width of about 8.2 inches and a diameter of about 25.4 inches and will require precise wheel offset to avoid tire rub.
 
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B

Bill Blue

Platinum Level Sponsor
All of which needs to eventually be incorporated into the "why I built my car the way I did" narrative cause the final product is a compilation of detail oriented decisions.
Bill
 
C

Charles Johns

Donation Time
OKAY guys, I already have my 14" x 6" wheels but I will consider new 15" x 6" rims...and start my search for econo-car sporty tires. Maybe what is used on those little front-wheel drive autocross screamers. And I understand "off-set" makes a big difference, and contact-patch is not the same as tire width. Like my belly is not the same as my belt size!!! THANKS!
 
DanR

DanR

Diamond Level Sponsor
The P195 55 15 BF Goodrich tires look nice to me mounted on 15" dia 7" wide wheels and seem a near perfect fit on my Blue Boy V6. Handles nicely too.

I don't have the road noise associated with some other cars I've been in over the years.
 
C

Charles Johns

Donation Time
Building this little car is just as different as night and day compared to building a Street Rod. Similar but different. I am building to drive to Canada, Florida, or California if I feel like it, and not worry. The only time I took a regular late model car on vacation was in a 1977 LTDII all over the west. Fun showing the daughter who was 9 at the time, Yellowstone, Pikes Peak, Salt Lake City, Carlsbad Caverns, etc. but not the same as when driving a 1932 Ford coupe, a 40 Ford coupe, or a 1965 Mustang. Not near as much fun. Just like building...getting there is over half the fun. The last car I built for my high-roller friend was a 1940 Nash 2-door with big Ford V8, cruise, tilt, chopped top, many custom mods and interior. His accountant said he had $65,000.00 in it in 1992. A guy told him he could have bought a Porsche, BMW, or Lambo for that back then. Pat said, "YES, but at the airport I would see others just like mine, but not in my NASH, and I'll never see myself coming down the road. I always liked his answer.
 
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Charles Johns

Donation Time
Question PROCRAFT, the new style low profile tires with small (not much) sidewall, removes much of the flex the sidewall gives to the suspension. Since our older suspension is different from today's cars, how much suspension change do YOU think is necessary to benefit from the newer tires? Obviously they will not "roll" as much in turns but will definitely transfer more road imperfections to the chassis, but is it enough to require more movement in the suspension? The old leaf spring-50/50 shocks with the shocks canted at the top about 60 degrees worked fairly well on the street, but gas shocks at that same 60 degree cant don't appear, at least in theory, to work as well. There is little if any force needed to extend the shock and at an angle, while one was compressing in a turn, the opposite side was extending...which required considerable pressure in a 50/50 shock. That minor difference seemed to help body roll in Hot Rods and customs, but I am not sure 50/50 shocks are even made today. ANY help appreciated, plus I may be totally off base on my thinking with today's parts.
 
C

Charles Johns

Donation Time
THANKS 260, I'll start looking for 15" rims. Do you know if a taller tire will work? Since I hope to drive across America (at least part of it) I want the best MPG I can get. Taller rear driving tires help. That was one major reason for the 205 x 70R - 14" tires. Any ideas from anyone about a fan for the 2.3 is appreciated. I have only 1 3/8" between water pump and radiator and with AC, electric fans may be out of the picture. I think a 14" flex-fan may work. The little car is a royal pain but I love it.
 
260Alpine

260Alpine

Silver Level Sponsor
I wouldn't go any higher than 65. 70 will be too tall. The size I mentioned is a couple inches taller than the original 13's. As others have mentioned the 25 mm offset fits good. Norcal on this board just got new tires and wheels in those sizes.
 
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Bill Blue

Platinum Level Sponsor
The space crunch comes down low at the front of the fender and usually needs "adjustment". Build to fit your car, cause every one of them is different, even side to side. Most guys start having problems at around 185-65, depending on wheel width, offset, phase of moon, etc. But the 185-195 aisle is where to be shopping.

Bill
 
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Barry

Barry

Diamond Level Sponsor
The factory 5.60-13 tires had a diameter of about 22.2" and the 5.90 or 6.00-13 tires had a diameter of about 22.8". IMO, the visual sweet spot on a Series Alpine is about a 24" diameter tire.

With a 3.89:1 rear end and a 0.75:1 overdrive at 70 MPH:

185/50-15 (about 22.3") tires would be about 3200 RPM

185/55-15 (about 23.0") tires would be about 3100 RPM

185/60-15 (about 23.7") tires would be about 3000 RPM

185/65-15 (about 24.5") tires would be about 2900 RPM

185/70-15 (about 25.2") tires would be about 2800 RPM​

Using extremely large diameter tires that would look strange and would almost certainly result in tire rub is not worth a drop of a couple of hundred RPM at cruise. To paraphrase Casey Stengel, you could do the math.
 
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PROCRAFT

Donation Time
205/55/15 23.9x8.1
195/55/15 23.4x7.7
185/60/15 23.7x7
185/55/15 23x7.3

With the T5 I'm running and a 205/55 tire and a 3.27 gear 68 mph @2500
 
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