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.

CR-1 seem stiff enough, for me anyway... Seem stiffer vs. A052, but it's been a year and a half and I only ran those tires on the Cayman.

I liked the feedback I got from the CR-1s and they were imo pretty tenacious, I could really drag the car down to the apex.

Just received my 255 CR-1's.
My old 255 Yok A052's are measuring 10" total width mounted on a 9" wide wheel.
The un-mounted 255 CR-1's are measuring 10.25" total width.

I'll report back with mounted width in a couple days.

That's alot of meat. You boosted or NA?

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NA. Just a header and tune. Car is setup for autocross in STX class, so not much power, all about the cornering grip.

255/40R17 CR-1's on 17x9" +40mm wheel.

Just went out and did a little scrubbing. No issues with rubbing that I didn't already have with my 255 A052s (inside front at full lock)

Thanks, Breezio!

I've got mine on order now :)

BTW. First event on the CR-1's went great. Got to try them in wet and dry, performed well both times. Very similar to Yok's.
On the second day, scrubbed in and a good heat cycle, pulled 3rd Pax and 8th Raw (second fastest car not on Hoosiers) out of 60 drivers.

Second event is this weekend. Should be dry and hot. I'm excited.