Anyone mounted up 255/40R17 Nankang CR1s?
 

I've heard these fit VERY wide - like 275/285ish.


Curious what people's experiences have been with our platform? I have run 255/40R17 AR1s without any rubbing or issues, but they only ran a touch oversize I believe.


Also curious on feedback from anyone who has driven both these and A052's on track. A052s have pretty soft sidewalls - do the CR1s share this trait?

Hoping to mount some up as soon as they arrive.

I'm not sure about the 255's, but a buddy running STS with 225's, his 225 Yoks are wider then his 225 CR-1s.

I'm really interested to see how fast they are compared to the A052's. Tread design on them is very similar.

https://philstireservice.com/wp-cont...CR-1-Specs.pdf
According to this, 255/40-17 have 259mm section width on 9" wheel.
I'm running 245/40-17 on 9" wheels, but to me they look wider than the 249mm shown here, I would have guessed 255 minimum, so...

Ran these at New Hampshire Motor Speedway (chicane/chicane) yesterday, did a best lap of 1:19.26, unfortunately not in my time trial... I ran 1:20.20 time trial same car on 245/40-17 RE71R a couple of years ago.

Also, my 255 CR1s are arriving on Monday. I'll let you know when I get them mounted.

Looking again, 249mm for section width seems about right, the sidewall is a lot more square which makes them look wide. 245/40-17 has 9.8" section width, 9.6" treadwidth, vs. A052 with 9.9" section width, 8.9" tread width.

Just saw a YT video on this and they run wide. I'd you want to fit a 255 you should get a 9.5 inch wheel. 245 will fit nicely on a 9 inch wide rim

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I have 255/40/r17 CR1 on my 17x9 Rays 57CR. what exactly are you looking for?

https://i.imgur.com/RQm7pIw.jpg

Wait, the tread width is 9.6"? That seems really wide for a 245/40-17 :eyebulge:

Works out about right. 9.6X25.4 = 243.84mm

My 245 RT660's just showed up and they measure about the same.

I'm concerned about rubbing issues, mainly.

I was fine with 255/40 AR1s and RS4s - just concerned about the CR1s, as I heard rumors the 255's runs especially wide. The 255 AR1s are sized closed to a traditional 265, for instance.


I'm also curious about feedback on sidewall stiffness compared to A052s, which are a bit soft.

Dont know about CR1s, but 255 Falken Rt660 are wider than 275 Maxxis RC1.

Feedback is good. I'd rate it better vs a052 with the caveat that I ran those on a 987. Cayman. Drawback is weight, the cr1 is about 3 lb heavier. Which according to data nullified any power gains I got from. Ace350 header and tune...

But enough more grip that I got fuel starvation coming out of turn 6 (180 degree banked left aka "the bowl) at NHMS at 7/8 tank, which has never happened before. Palpably more grip vs RE71R I used to run, or even 8-cycle Hoosiers I ran there last Fall

Thanks, Dan.


How is the sidewall stiffness on the CR1? A052 are pretty soft in that respect.