Tyre specs

[stephen low]

Have made an enquiry of tire rack regarding available tyres and provided some standard oz specs ie width, series and profile yet I've been asked to specifiy wheel height.

Is there an easy way of getting this dimension as I know of one set of front tyre option I can chase but really have no option in mind for my rear set.

Guess I am also limiting myself as I'd like to get vintage wheels down the track and am struggling with the 15 or 17 inch choice as a trade off between the more period look of the 15's versus a far wider range of tyre choices in the 17's.

Anyway for now can anyone advise as to how I work out tyre height as the US seem to like to spec up their tyres and as I've been requested to provide.

Cheers

[Tenrocca]

Slowy,

Total diameter = rim diameter + aspect ratio * width * 2

eg. a 285/40/17 is

= 17 x 25.4 + 0.4 (which is 40/100) x 285 x 2

= 659.9mm

= 26" (actually its 25.97")

Hope that helps

Cheers

[Shelby400]

Bloody maths teachers.

[stephen low]

Thanks Tenrocca, perfect.

I guess I should also ask the question on tyre series where for 15" tyres the tendency is to run 60 series front and 50 series rear is that right?

And then for the 17" option, what do people tend to run front and rear for both series and profile depth?

Cheers

[Tenrocca]

I have 245/45/17 and 285/40/17 front and rear - on a 8" (F) and 9.5" (R) rim. I think the tyre sizes are pretty typical for 17" - Just had a quick look and the next size up I could find in a 17 was a 335 /35 /17, gives you an overall diamter of 666 (not good if your superstitious perhaps). There is probably something inbetween but I couldnt find it on my quick look. (edit - obviously there is 315/35/17 ) Cant comment on 15" sizes but 60 front and 50 rear does ring a bell for some reason.

Cheers

Edit - Also I think the bigger overall diamter you can get looks best to fill the gaurds as much as possible.

[400TT]

These sizes seem to be popular up here with the Cobra guys running 17" 'Vintage Wheels US' wheels. I've supplied 3 x sets this week alone.

Sumitomo 245/45/17
Sumitomo 315/35/17

Tire Rack stock them.

[Rebel1]

Slowy, in 15" sizes the popular sizes seem to be 235/60/15 or 245/60/15 and 295/50/15 on the back.

The main reason is that the diameter is approx the same. The 235/60/15 Yokohama Y352 ( a very average street tyre ) is 665mm diameter and the 295 is 677mm so very similar. Very slightly larger in the rear but that fits the traditional image.

However, some do run 275/60/15 rears but they are 711mm diameter and to my eye look a little big. The 255/60/15 is a popular rear that also looks good at a diameter of 687mm.

The 265/50/15 is a matching rear to a 225/60/15 front tyre.

I very much like the 235/60/15 and 295/50/15 combo for those wanting traditional baggy 15" tyres.

[Rebel1]

Originally Posted by Tenrocca

Edit - Also I think the bigger overall diamter you can get looks best to fill the gaurds as much as possible.

Certainly true but be very careful. Many 17" tyres are smaller in diameter because of their shorter profile.

If handling is important then go the 17".

[400TT]

I'm with Rebel1, my ideal Cobra tyre sizes in 15" are 245/60 & 295/50. That's what I fitted to my last Cobra.

15" tyre choices are extremely limited again now.

I bought Yokohama Avid S/T 245 & 295 in 15". A very good street tyre, wouldn't hesitate to recommend them, but unfortunately yokohama must not have been selling enough, as they are now dropped.

Or you could get some better straight line traction and fit some street Mickey's to the rear.

[Rebel1]

Certainly not a huge range available in 15", but there is a reasonable selection.

Some I have identified in 235 or 245/60/15 and 295/50/15 with matching treads:

BFG T/A
Goodyear Eagle
Firestone Firehawk Indy 500
Yokohama Y352
Cooper Cobra
Mickey Thompson Sportsman S/T
Avon CR6ZZ ( street legal performance tyre)

Prolly a few more.

[G_Edmonds]

Remember to take your brakes into account. Anything larger than 11"(280mm) will force you to go to a larger diameter wheel.

[400TT]

Yeah, there is a selection of 15" tyres in suitable sizes. But you can get 17" tyres that are both cheaper and perform better.

And that's the problem for guys chasing the vintage 15" look.

And if you want to upgrade to race rubber, it's a little more difficult at 15" to get the wider sizing for the rear.

Yeah, good point with the brakes. I have gone up to 310mm rotors with 15" wheels, but that's cutting it a bit fine with caliper choices and position. And there is no room for further upgrades.

There is no right or wrong answer when it comes to deciding between 15" & 17". Stephen is in for one tough decision.

[stiffy]

So then,

245/295 15" what would be the best for 95% street and 5% track.

I would like to have the white writing still.....



BFG T/A
Goodyear Eagle
Firestone Firehawk Indy 500
Yokohama Y352
Cooper Cobra
Mickey Thompson Sportsman S/T
Avon CR6ZZ ( street legal peformance tyre)


STIFFY

[AC302]

Slowly,
Just bought new whels and tyres for my car. I'm looking for a home for the current ones. They are 15' and will do you until you could save up for the Vintage wheels you want. PM me if you want more detail.

[stephen low]

Jeremy PM sent.

Slowy

[Rebel1]

Originally Posted by stiffy

So then,

245/295 15" what would be the best for 95% street and 5% track.

I would like to have the white writing still.....
STIFFY

No white writing ... but the MT S/R has had good reports. Modern tread pattern tho.
http://www.mickeythompsontires.com/s...em=SportsmanSR
26X10.00R15LT and 26X12.00R16LT