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tr 4 tire size

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Pauly06

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What size tire will fit on a 1964 tr4? I saw some 165 80 15's in a tire flyer and was wondering if they would work.
 
For stock rims, that is the correct size. What brand and source are you looking at?
 
Kumho tires through Tire Rack (tirerack.com) are very cost effective.
Bob Muzio
 
Use the link in the upper right corner. It helps support the BCF!
 
I think the original tires were 165-15 not 165 80 15. My tire guy said the 4.5 inch rims were too small for the 80 size wheels. The 165-15 are the same as the original VW bug so they are still available all over.
 
Amazing how limited the selection is for stock size on these cars... especially since the most popular car of the 20th century used the same size tires as the TR2/3/4.

I run three sets (1 wire, 2 disc): Michelin, Dunlop & Cooper because each time I buy a set the manufacturer promptly discontinues this size. I will try to drive Kumho out of the market next go-around.

As for the "upper right corner"... I have used Tire Rack several times and was always pleased. They ship the hard to find good deals to a local shop where the tires get mounted, etc.
 
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Amazing how limited the selection is for stock size on these cars... especially since the most popular car of the 20th century used the same size tires as the TR2/3/4.

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I agree. 165R15 tires are not easy to find. I had a heck of a time finding a set a couple of years ago.
 
I have always thought the 165 SR 15 and the 165-80-15 were the same thing. I looked up the kumho 165-80-15 at the Tire Rack and the 165 SR at Coker; they have the same section and diameter.
 
TRMark, are you sure? I bought the 165 SR 15 size, like from a VW, but they are sort of a narrow "medium quality" tire. Nothing like Vredestein or whatever that cool brand is. My alignment mechanic scolded me. Since then, I've wondered about a wider tire, but people talk of excessive stress on the wishbone or fulcrum assembly if you're not careful. This is probably an old worn out subject, but I'd like to learn more. Maybe I'll search the archives . . .
 
My recollection was that if the aspect ratio was not shown on a tire it was a "90" or "100" series tire. From somewhere I recall seeing that the aspect ratio of the typical 165/15 was in the mid-80s.
 
Geo, I don't think it's quite that bad. But I do recall reading somewhere that, for example, the "dreaded" Michelin X redline 185-15 (apparently just very recently no longer available from Michelin) is somewhere around an 82 or 84% aspect ratio.
 
165R15 and other early radial tires are referred to as 82 series. Again if you look at the specs at Tire Rack and Coker you will find the section and diameter to be identical between the 165R and the 165/80. I measured an old somewhat worn XAS 165HR15; diameter is 25.3" section 6.5". Also measured an old original equipment X 165SR15; dia. is 25.5" section 6.3" The X is more worn out that the XAS. The specs at Tire Rack for the Kuhmo 165/80/15 show a diameter of 25.4" and a section of 6.5".
I think that the biggest difference between the tire designations is the price and if you seek to have the original appearance of a XAS.
 
I looked into this before and I think the 165-80's are about as close as you are you will get to original. Somewhere on the internet they quote the original aspect ratio as 78's, though I won't quibble with TRMark's comments of them being 82's.
 
The only reason I was worried about the 165-80 was the tyre shop looked up the rim width minimum for that size tyre and it was larger then the TR4 rim. The minumum width for the 165-15 was smaller and did match the TR4 rim size. Now that may not be a problem in the end as perhaps the small rim width did not exist any more once the 165-80 tyres were made so they did not bother adding that rim width to the list. Who knows?? I would love to be able to just use any off the shelf tyre, as it would save time and money.
 
The paragragh below is from the Cooper tire website...



For example: For tires with aspect ratios from 80 to 50, the measuring rim, also called the design rim, is specified to be 70% of the section width. For tires with an aspect ratio less than 50, the measuring rim is 85% of the section width.

If we take 165mm and multiply by 70%, you get 115.5mm, which is equal to 4.54"...just what the TR4 rim is.
 
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I looked into this before and I think the 165-80's are about as close as you are you will get to original. Somewhere on the internet they quote the original aspect ratio as 78's, though I won't quibble with TRMark's comments of them being 82's.

[/ QUOTE ]

It is kind of confusing. I went through this before also. I have heard them called 78s also. When the "82" designation is used it is in quotation marks such as on a chart at the Tire Rack website. If you plug the numbers into one of the tire, roadspeed, RPM calculators on the internet 165R15 comes out to be an 80. Then if you plug in the TR gear ratio numbers into the tire chart and compare them to the road speed data in the back of your Triumph owners manual, the Michelin X listed comes out real close to an 80. The wheel range listed for both the 165R15 and the 165/80/15 is 4" to 5.5"
 
I think the 78 aspect ratio dates back to the bias-ply tire days when 70s were the wide tires common on US muscle cars and tire width was designated by a letter in the U.S..

When radial tires became more the norm, and a metric tire measurement was used, the 82 percent ratio replaced the 78 as used as radials were foreign made and sized metrically (on 15" wheels!).
 
Yokohoma sells a wonderfull 185/65 15 that fits the early 4 VERY well.Mine are mounted on Dayton wires and have been trouble free for 20k. I would recomend these tires for most street uses.
MD(mad dog)
 
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