21" Radial ply tyres

[Synchro909]

There has been discussion here now and then about radial ply tyres but nearly always 19". The general consensus seems to be that they improve the ride and road holding no end and I don't doubt it. Does anybody have experience with the 21" version. Coker don't say much about them on their site. I even had to enlarge the picture to be able to see that they are 5.50/6.00R21. At those figures, it seems to me that they are probably quite large and the rolling diameter would be about 2 1/2" more than the standard 21' cross ply tire and the tread much wider.
At $240 each, they are cheaper than the 19" ones (surprise) so I either buy a set of those or buy a set of wheels, then pay more for the tyres as well. Over here, pre-depression (28/9) cars are more common than 1930 ones and no 1931 Model As were sent to this country in the day. Finding a set of 19" wheels won't be as easy as over there but if I buy in the US, I don't get to inspect them and then there is the freight. AARRGGGGHHH!
I'm leaning towards the 21" tyres for obvious reasons but would like to get some feedback first.
Thanks in advance.

[Tom Wesenberg]

Aren't they made by the same company, so the results should be the same?

I haven't tried either, as they are outside my budget.
I just bought a set of four 225-75-15 whitewall radials for $276 for all 4 delivered to my door, for my Studebaker.

[Synchro909]

Originally Posted by Tom Wesenberg

Aren't they made by the same company, so the results should be the same?

I haven't tried either, as they are outside my budget.
I just bought a set of four 225-75-15 whitewall radials for $276 for all 4 delivered to my door, for my Studebaker.

Yes, made by the same company and as you say, the results should be the same. My question is about their large size will affect gearing and whether the high aspect ratio I expect they have will affect road holding.

[jhowes]

Might I ask what an "aspect ratio" is and how does it effect road holding? Jack

[Railcarmover]

Originally Posted by Tom Wesenberg

Aren't they made by the same company, so the results should be the same?

I haven't tried either, as they are outside my budget.
I just bought a set of four 225-75-15 whitewall radials for $276 for all 4 delivered to my door, for my Studebaker.

Nice...Im running 16" wheels on the A,thinking about 'chinese maypops' as well,can grab a set of 205/75 r16 radials for $48.50 a piece at Wallyworld..

[denniskliesen]

I checked price last night @ Coker and they were $313.00 Where are you getting $240?

Just looked at price again and when looking for Excelsior radial it states starting @ $240 but that is for the least expensive of all sizes for that radial. If you choose 21" from the side bar it corrects to actual price $313.00 Plus you need radial tubes. Best to call Coker and ask questions. They show that tire mounted to a Model A 21" rim and we can assume they will work, but yes they are about 2" larger diameter at 32.10" I'm not ready for tires yet but would like to have a set before going on long tours.

[barkleydave]

Handling will be different but also radial profile will put a lot more side torque on the 21 wheels hubs and spokes. Radial do not drift like bias tires.

[Curtis in MA]

Why do you need special tube? Are radial tubes different?

[1931 flamingo]

Any new tires are going to give you a better ride and handling. JMO
Paul in CT

[Synchro909]

Originally Posted by jhowes

Might I ask what an "aspect ratio" is and how does it effect road holding? Jack

The aspect ratio is the ratio between the tread width and the height of the walls. Eg, a 205-60 X (say) 16 tyre has a read width of 205 mm and a wall height of 205x60%= 123mm. 16" is 406mm so the inflated tyre would be 406+(2x 123)+ 652mm diameter. The higher the walls of a tyre, the more flexing you get as you corner and the more it will want to wander in a cross wind etc

[Synchro909]

Originally Posted by denniskliesen

I checked price last night @ Coker and they were $313.00 Where are you getting $240?

Just looked at price again and when looking for Excelsior radial it states starting @ $240 but that is for the least expensive of all sizes for that radial. If you choose 21" from the side bar it corrects to actual price $313.00 Plus you need radial tubes. Best to call Coker and ask questions. They show that tire mounted to a Model A 21" rim and we can assume they will work, but yes they are about 2" larger diameter at 32.10" I'm not ready for tires yet but would like to have a set before going on long tours.

http://www.cokertire.com/tires/style...m_diameter=121 is where I got the price. There is only one size made for 21" wheels and Coker says they don't make a tyre for the Model A rim yet they show the tire mounted on one. What is going on?

[Synchro909]

Originally Posted by barkleydave

Handling will be different but also radial profile will put a lot more side torque on the 21 wheels hubs and spokes. Radial do not drift like bias tires.

Barklydave, I'm not into drifting my Model A but even with cross ply tyres, I have pulled spokes off the rim and split the centres due to strong and consistent crosswinds over a coupe of weeks driving every day - a total of about 4,000 miles.

[barkleydave]

Yup for sure... not intentional drifting however bias tires will break loose sooner than radials so less strain on the wheels. I folded a 48 spoke wheel on an MG when I changed to radials and was driving it hard. folded like a playing card! Ouch..

[aermotor]

Post #12 & #13 were my main concerns. With todays roads I can live with the slight wandering more than busted wheels.

John

[2manycars]

Originally Posted by barkleydave

Yup for sure... not intentional drifting however bias tires will break loose sooner than radials so less strain on the wheels. I folded a 48 spoke wheel on an MG when I changed to radials and was driving it hard. folded like a playing card! Ouch..

That is why we use 60 spoke wheels on our MGs over here. Especially in the east where there are lots of twisty roads.

[Synchro909]

I sent a "contact us" to Coker asking about these tires and they replied that they don't make a radial tire for a 21" Model A wheel. I replied asking why is it then, that you show one mounted on a 21" Model A wheel on your website? There has been a deafening silence since. So much for customer service! So much for honesty in advertising!

Late addition: Coker have responded and say that the only 21" tire they make is 5.00/600R21 and is too wide for the Model A wheel. That sounds more than reasonable so it looks like I might have to find a set of 19" wheels (not so easy here).

[NCRebel]

There are two brothers that visit my car every home football game I attend. These men are in their + 70's. They talk about racing the Model A's they had as young men. One brother admitted he would win by using 21 inch tires while his brother had 19's. They said the road conditions were no factor in the outcome, just the extra diameter of the tire.

They winked a lot and smiled as they remembered the tale.

[updraught]

The Comp V 600x21 supposedly can go on a 2 1/2 inch rim!

The 19 and 21 inch radials are unlikely to fit any pre war cars as most did not have 4 inch rims.

[2manycars]

Coker old stock radials. Not for road use.

https://www.cokertire.com/550-600-21...or-comp-v.html

[Synchro909]

Originally Posted by 2manycars

Coker old stock radials. Not for road use.

https://www.cokertire.com/550-600-21...or-comp-v.html

They are Bias ply and most likely all gone by now. Thanks anyway.