Bias to radial conversion

Bill Leverett

Bill Leverett

PCS Member/Paramedic Supervisor
What radial tire is comparable to a 8.90 x 15 load range "D" tire?

I know it must be an extra load tire at least...just not sure about the rest.

Thanks.
 
Bill Leverett said:
What radial tire is comparable to a 8.90 x 15 load range "D" tire?

I know it must be an extra load tire at least...just not sure about the rest.

Thanks.
Click to expand...

I use 235 x 75 x 15 Extra Load tires on my cars. I have Broadway Classics on my 1978 Superior, however, they have gone out of business. On the 1969 Miller Meteor and the 1963 Chrysler, I used Kelly Springfield Navigator Gold extra load tires, and they have been discontinued since I purchased them. If you contact Kelly Springfield, they can tell you which warehouse still have them in stock. They are a great riding tire, and an excellent brand. Kelly Springfield is a division of Goodyear rubber.
If you want a true "truck" type of tire such as was originally installed on your car, then Diamondback Tire is the way to go. They can add a white wall to any black walled tire that you like.
 
No local warehouses have the Navigator Gold anymore...at least not in the 235 size. I recall a posting that mentioned the Kumho Solus KR21 that is avalable in the 235/75 R15 size plus it's rated at 2205 lbs per tire (according to the chart). Plus they're relatively inexpensive via Tirerack ($77) Anyone have any experience with this tire?

I have a set of the Navigator Gold 225/75/R15 for my Pontiac. These tires will be for something else.
 
Bill Leverett said:
No local warehouses have the Navigator Gold anymore...at least not in the 235 size. I recall a posting that mentioned the Kumho Solus KR21 that is avalable in the 235/75 R15 size plus it's rated at 2205 lbs per tire (according to the chart). Plus they're relatively inexpensive via Tirerack ($77) Anyone have any experience with this tire?

I have a set of the Navigator Gold 225/75/R15 for my Pontiac. These tires will be for something else.
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I have them on my Criterion and drove from SD to CA when they were new. They are smaller than what came on the car from the factory, and the speedo is now off by 8 or 9 MPH.
 
going radial

When you get to the point of changing to radials most tire shops will tell you that 235s are what you need. If you can determine what the diameter of the original tire was you should try to get radials that somewhat match that. Use a GPS to check your speed. Most of them will tell you your vehicle speed. I put radials on my 61MM this past year. BF Goodrich 235x75x15 was the size. My GPS says I am 3mph short on speed. No speeding tickets if I leave it at this. All the 235s seem to be a bit short on the diameter of the old bias type tires. Some more than others. So when I go shopping for whitewall radials I will be taking my tape measure with me. Since Diamondback can make about any size white wall I am leaning their direction for now. The improved stopping and overall handling has convinced me to not go back to bias tires.
Mike
61 MM
 
Tires

Kumho Solus KR21 that is avalable in the 235/75 R15 size plus it's rated at 2205 lbs per tire (according to the chart). Plus they're relatively inexpensive via Tirerack ($77) Anyone have any experience with this tire?
Click to expand...

62 Buick Kumho,s 93S&S Kumho,s 61 S&S Kumho,s So far no problems , but I have never taken any trips over about 300 miles.


 
I have Kumho's on my Lifeliner as well. Like Robert stated, the size is slightly off so the ambulance speedometer reads faster than actual. I rode on them to Flint and back and I like them. :my2cents:
 
you want the right tires on it go to the 700 x 15 the only ones you will find a radial in are toyo and yokohama neither have a white wall. but they are the only 15 inch 31 inch in diaminator tire you can get in 8 ply. the problem is they are right at 200 each and diamond wants 70 a tire to cut in a WW.
 
This is the best tire interchange / referance chart that I have ever found on the internet. More information than you might even want to know... Please keep in mind that there are slight variations of physical size by the manufacturers of the various brands.... (thanks to turbincar.com)

Click here..

________________________________________

This site will explain the markings on the side of modern tires.... (thanks to Hemmings and San Jose Classic Chevys Club)

Click here..

http://www.miata.net/garage/tirecalcold.html
 
I'm thinking of doing the opposite .... going from radial back to bias on the '72. Coker sells a dual stripe that matches the original equipment. Has anyone bought a set that can comment on their experience?
 
they left off the 700 x 15 as it's a truck tire. but they are still the only one you can get that are the 31 inch in diameter. really there 30.5 that you can get with the proper load rating in the proper ply rating. the 235 x 15 are a 29 inch tire. this set of pictures really show it the center tire is the 700 x 15 bias ply hercules tire. the bottom is the the distance of roll out of each tire. i was looking for a replacement for the h78x14 on my 67 so though as long as I was compairing I would do everything I had.
 

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Kevin M. Parkinson said:
I'm thinking of doing the opposite .... going from radial back to bias on the '72. Coker sells a dual stripe that matches the original equipment. Has anyone bought a set that can comment on their experience?
Click to expand...

If you are only going to be driving it locally, then bias tires are OK, however, if you are planning on driving any distance, then the radials will give you a better ride, and a better feel of the road. I have a 1964 Corvair Spyder that I had put radials on prior to the restoration, and went with period correct bias ply tires after the restoration. The handling of the car was great with the radials, and it is a chore to drive it any distance with the bias ply tires. I generally am a preservationist, trying to keep the cars as close to original as built as possible, however, when it comes to tires, I prefer to use the radials with a correct looking whitewall. Today, some companies are making radial tires that have the look of the bias ply tire and the handling character of the radial. Usually they are closer to a truck tire than a passenger car tire. Your best bet of finding these tires is with Diamondback Tire...
 
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