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New Kr448/9's


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Has anyone tried out the new Dunlop KR448/KR449 tires? I had a great experience for a short time last year on my GP211A's (didn't last long at Putnam) as they stuck like glue and I could ride hard all day. I was thinking of getting n-tec slicks last year although I was advised when I was at Barber to go with Q2's since it was cold. I low-sided the 3rd session, not fully sure why, but I'm liking the idea of getting the stickiest tires I can find!

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Has anyone tried out the new Dunlop KR448/KR449 tires? I had a great experience for a short time last year on my GP211A's (didn't last long at Putnam) as they stuck like glue and I could ride hard all day. I was thinking of getting n-tec slicks last year although I was advised when I was at Barber to go with Q2's since it was cold. I low-sided the 3rd session, not fully sure why, but I'm liking the idea of getting the stickiest tires I can find!

 

The KR448/KR449 USA made N-Tec slicks are made in the same compounds and the same construction as the D211GP-A just with no tread.

 

They are an upgrade in performance, last longer and are the same price.

 

They have the current track record at Chuckwalla, and, in testing, they have lapped at 0.5 sec under the track record at Homestead.

 

The WERA National Endurance Championship was also won on the KR448/KR449 slicks.

 

You can read about the available sizes and specs here.

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The KR448/KR449 USA made N=Tec slicks are made in the same compounds and the same construction as the D211GP-A just with no tread.

 

They are an upgrade in performance, lost longer and are the same price.

 

They have the current track record at Chuckwalla, and, in testing, they have lapped at 0.5 sec under the track record at Homestead.

 

The WERA National Endurance Championship was also won on the KR448/KR449 slicks.

 

You can read about the available sizes and specs here.

I noticed the front is a slightly different size than the usual, but I assume the sizes can work on a CBR600F4i which I have, right? (125/80 front 190/55 rear). For an abrasive track like Putnam, what compounds do you recommend? Certainly not soft.

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Stevo,

We used these tires on our bone stock (except slip on) R6 at Road A for the endurance championship. We came in third. I have ridden on these tires at Jennings JP in 40 - 45 degree temperatures and at NOLA Motorsport park in 40 degree temperatures. They are the real deal....GET THEM.

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Stevo,

We used these tires on our bone stock (except slip on) R6 at Road A for the endurance championship. We came in third. I have ridden on these tires at Jennings JP in 40 - 45 degree temperatures and at NOLA Motorsport park in 40 degree temperatures. They are the real deal....GET THEM.

OK... you sound convincing! I just want to understand the compound types. But I like what you say about the performance in cool temperatures.

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  • 2 weeks later...

 

I noticed the front is a slightly different size than the usual, but I assume the sizes can work on a CBR600F4i which I have, right? (125/80 front 190/55 rear). For an abrasive track like Putnam, what compounds do you recommend? Certainly not soft.

 

The front 125/80x17 is the same dimensions as the 120/70x17 D211GP-A, the are identical in shape, width and height.

 

For Putnam, which is very abrasive, use a med(5436) or med+ front and the med(5436) rear.

 

If you are doing track days, stick with that compound. There is nothing to be gained at a track day by going softer. Softer will wear out quicker and not do what you need for a trackday.

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  • 4 months later...

 

I noticed the front is a slightly different size than the usual, but I assume the sizes can work on a CBR600F4i which I have, right? (125/80 front 190/55 rear). For an abrasive track like Putnam, what compounds do you recommend? Certainly not soft.

 

The front 125/80x17 is the same dimensions as the 120/70x17 D211GP-A, the are identical in shape, width and height.

 

For Putnam, which is very abrasive, use a med(5436) or med+ front and the med(5436) rear.

 

If you are doing track days, stick with that compound. There is nothing to be gained at a track day by going softer. Softer will wear out quicker and not do what you need for a trackday.

Steve, I'm going to get a set of slicks like you suggested above, but I got your email the other day and read about the new 7455 and 8477 compounds. For Putnam, which is abrasive like Mid-Ohio, should I be trying the new compounds or is the 5436 OK?

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  • 3 months later...

I noticed the front is a slightly different size than the usual, but I assume the sizes can work on a CBR600F4i which I have, right? (125/80 front 190/55 rear). For an abrasive track like Putnam, what compounds do you recommend? Certainly not soft.

 

The front 125/80x17 is the same dimensions as the 120/70x17 D211GP-A, the are identical in shape, width and height.

 

For Putnam, which is very abrasive, use a med(5436) or med+ front and the med(5436) rear.

 

If you are doing track days, stick with that compound. There is nothing to be gained at a track day by going softer. Softer will wear out quicker and not do what you need for a trackday.

Steve, I'm going to get a set of slicks like you suggested above, but I got your email the other day and read about the new 7455 and 8477 compounds. For Putnam, which is abrasive like Mid-Ohio, should I be trying the new compounds or is the 5436 OK?

 

i was looking at the dunlop site & noticed there are 2 med+ compounds (7455 & 8477) what is the difference, i would like to know as well, thanks in advance.

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  • 3 months later...

7455 is med, 8477 is med+

 

I very highly recommend the 8477 for any track day riding. very grippy, consistaint and last a long time.

 

It also can win an AMA national, like it did in Mid Ohio and NOLA.

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7455 is med, 8477 is med+

 

I very highly recommend the 8477 for any track day riding. very grippy, consistaint and last a long time.

 

It also can win an AMA national, like it did in Mid Ohio and NOLA.

I'm planning to order some 8477 GPA rears for use at NOLA. I have a couple 5436 GPA fronts already. Any reason I shouldn't use the 5436 front in combination with an 8477 rear?

 

Also, I would like confirmation: the 190/60 GPA rear is not the same dimensions as the 190/55? It seems clear by the public specs but I'm just double checking...

 

190/55: Width (188.5mm/7.42"), Diameter (647.3mm/25.48")

190/60: Width (191.3mm/7.54"), Diameter (657.4mm/25.92")

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  • 1 month later...

7455 is med, 8477 is med+

 

I very highly recommend the 8477 for any track day riding. very grippy, consistaint and last a long time.

 

It also can win an AMA national, like it did in Mid Ohio and NOLA.

I'm planning to order some 8477 GPA rears for use at NOLA. I have a couple 5436 GPA fronts already. Any reason I shouldn't use the 5436 front in combination with an 8477 rear?

 

Also, I would like confirmation: the 190/60 GPA rear is not the same dimensions as the 190/55? It seems clear by the public specs but I'm just double checking...

 

190/55: Width (188.5mm/7.42"), Diameter (647.3mm/25.48")

190/60: Width (191.3mm/7.54"), Diameter (657.4mm/25.92")

 

YES, the 190/60 is a larger, higher performing tire. It will fit, no problem. All AMA teams use the 190/60. It works better and comes in the 8477 compound, and the 190/55 does not. If you are at NOLA, you clearly should have the 190/60 8477.

 

Have fun!

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  • 1 year later...

A year later on this post...... I'm at the B level and creeping into the lower (very lower) end of the A's. I'm moving from Pirelli SuperCorsa's to the KR448/449 8477 compound. I'm doing so because I liked the stiffer feel of past GPA's - tried the Pirelli's and feel just too much flexing (for me) under hard braking especially. Still a decent tire, just not for my style.

 

My questions are;

1) What hot tire temperature is best for the KR44x's (right off the track). Rule of thumb for most good street tires was keeping them about 140 +/- 5F. Same for the racing slick's?

2) Only monitoring tire pressure doesn't seem like the best overall way to manage tires - just sets a known starting point and for making temperature adjustments. Would you agree or am I overthinking this?

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