correct size tyres for 73 RSR front/ rear?

[adomakin]

anyone know the correct tyre sizes for a 1973 RSR?
front and rear? i have heard that getting the rear tyres is a problem.........

[Bill Verburg]

Front
230/600 on 9x15

Rear
260/600 on 11x15

[adomakin]

bill, what would the 600 part match to in todays sizes? 60 profile perhaps?

[nick-moss]

285/40 x 15 is a road tyre size, but it went out of production many years ago

[GeorgeK]

Adomakin,
230/600 means 230 mm wide, and 600mm in diameter
260/600 means 260 mm wide and 600 mm in diameter
This racing nomenclature is helpful when setting gearing for a particular track.

[Bill Verburg]

There are no exact modern equivalents, the #s work out to be pretty close to 225/35x17 and 255/30x17. But there are no tires available in those sizes.

235/40x17 and 265/35x17 are the closest modern street tire equivalents. At least in the specified tread width and overall diameter.

[nick-moss]

Hoosier do some DOT tyres that are very close to the original sizes, but they are not legal in the UK.

[adomakin]

i can get my hands on either 255/60/15, 275/60/15 or 265/50/15 tyres from new, how do they compare?

[nick-moss]

Check out the rolling circumferences here

[Bill Verburg]

a 230/600 is ~9"widex23.6"tall

a 260/600 is ~10.25"wide x23.6" tall

the tire you specified are all way too tall
255/60 is ~ 10 x 27"
275/60 is ~ 11 x 28"
265/50 is ~ 10.9 x 25.5"

Any of them are very poor choices

[adomakin]

how about a 265/40/15? i think i can get them new?

[Bill Verburg]

If you can find some(I can't) 265/40x15 are ~10.4"wide x 23.4"tall. They would be a good size for the rear.

[adomakin]

thanks very much people. bill, ill let you know if i can get them 265/40's if you are interested

[Early_S_Man]

285/40 - 15 ... 23.98" for front on 9 x 15 Fuchs

345/35 - 15 ... 24.53" for rear on 11 x 15 Fuchs

are a good match for the street on an RSR clone ...

The 345's are still available, and occasionally I hear about attempts by Pantera folks worldwide for a group buy of special-run batch of 285's.

[Bill Verburg]

I am certainly not interested in those tires but I am curious as to what manufacturer makes them.

The only 345/35x15 that I know of is the PZero at 13.9" x 25.9" an 11" rim is at the minimum end of the recommended range and as Warren pointed out there is no available mathing front.

[nick-moss]

I have a brand new pair of Yokohama AV1 345/35 ZR 15 for sale.

[RarlyL8]

I'm running 255/45-15 front 345/35-15 rear.
Never heard of a 265/40-15.
Yokohama no longer produces any of those sizes (255, 285, 345) in 15 inch.
23.6" is a short tire. You may want to consider the gearing you have when choosing tire sizes. An inch in tire hieght makes a noticeable difference in the final gear ratio. Going to a 17" rim with ultra low profile tires will also help out the handling.

[adomakin]

will a 345/35/15 fit under a 73 rsr arch? if it does then im all for it!

[RarlyL8]

Depends on the wheel.
Should work fine using the right width and offset.

[Jack Olsen]

I'm running 315's with a one-inch spacer. If you plan accordingly, it shouldn't be a problem at all.

Keep in mind, though, there's a point of diminishing returns, in terms of drag, where the width isn't getting you anything, if you don't have a whole lot of extra power to push it -- at least when it comes to lap times.

Rarly doesn't have that problem, of course.