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Discussion Starter · #1 ·
Howie all, I am a long time Dunlop user and just can't keep up with the prices and just switched and received a new set of Pirelli super Corsa (120/180/55) for a 600. I would like to know if I need to make any adjustment to the bike for difference is tire sizes. I tired searching for the tire diameter for Dunlop 209GPA UK 120 front 180/55 rear and got nothing. However, I did find sizing info on an older 208GP size. Any one know what diameter are the 209GPA uk? Or I need to make any adjustment at all? Thx.

Pirelli Super corsa front: 600mm
Pirelli Super Corsa Rear: 642mm

Dunlop D208 GP Front: 599mm
Dunlop D208 GP REAR: 643mm
 

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Discussion Starter · #4 ·
I would verify that the dimensions stated are the actual dimensions of the tire.
Thx so you think the number are incorrect? I got them off the net and guys you know how that goes.
 

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V4 CyclePath...
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Printed tire data is wildly inaccurate... try this handy racers tire formula... now
plug Pirelli's own data and you'll find the diameter...

TW x AR / MC + RS = D
tire width x aspect ratio / metric conversion + rim size = diameter

180 x .55 x 2 /25.4 +17 = 24.79 inches or 629mm...

Compare that with:

180 x .50 x2 /25.4 +17 = 24.08 inches or 611mm

So the diameter difference between a 180/55/17 and a 180/50/17 is 17.8mm or
.703 of an inch...
 

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Discussion Starter · #6 ·
Printed tire data is wildly inaccurate... try this handy racers tire formula... now
plug Pirelli's own data and you'll find the diameter...

TW x AR / MC + RS = D
tire width x aspect ratio / metric conversion + rim size = diameter

180 x .55 x 2 /25.4 +17 = 24.79 inches or 629mm...

Compare that with:

180 x .50 x2 /25.4 +17 = 24.08 inches or 611mm

So the diameter difference between a 180/55/17 and a 180/50/17 is 17.8mm or
.703 of an inch...
Thx larry but I was comparing to same sizing tire 180/55 to 180/55 but different brands. Pirelli vs Dunlop 209GPAs. I quess I have to just measure both sets to see.
 

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V4 CyclePath...
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Thx larry but I was comparing to same sizing tire 180/55 to 180/55 but different brands. Pirelli vs Dunlop 209GPAs. I quess I have to just measure both sets to see.
You're welcome... race slicks hit the size numbers more accuately than either
DOT race or street tires... thats because manufactures know that racers are in
tune with their suspension set ups and gear ratios whereas most customers
don't think about it all that much...

BTW I think a 180/55 is too large of a diameter for a 600s power... there is really nothing to gain...
 

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BTW I think a 180/55 is too large of a diameter for a 600s power... there is really nothing to gain...

They have been using 190/55 & larger tires on the 600 Race bikes for many years now and even club racers were shaving 1-1.5 seconds off their lap times with the larger tires (> 180/55)

Just because you lack the experience, skill or ability needed to discern the difference in tire size or how it relates to the overall geometry set-up or available traction does not mean there is "really nothing to gain".

Maybe you should try riding a current 600 instead of that old worn out antique 750 and you might realize how crappy MR. RC45 really is. :)

If the RC45 was a vagina it would look like two soggy strips of bacon smashed together and surrounded by some 70's bush.
 

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V4 CyclePath...
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They have been using 190/55 & larger tires on the 600 Race bikes for many years now and even club racers were shaving 1-1.5 seconds off their lap times with the larger tires (> 180/55)

Just because you lack the experience, skill or ability needed to discern the difference in tire size or how it relates to the overall geometry set-up or available traction does not mean there is "really nothing to gain".

Maybe you should try riding a current 600 instead of that old worn out antique 750 and you might realize how crappy MR. RC45 really is. :)

If the RC45 was a vagina it would look like two soggy strips of bacon smashed together and surrounded by some 70's bush.
Thanks for pointing that racing is where you can benefit because I
thought we were talking street... I don't lack the experience, skill
or ability needed to discern the difference in tire size or how it
relates to the overall geometry...

Good thing the RC45 is not a vigina Mr."I will whip my e-penis out for
you so we can settle this like men"
 

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Craft Int Instructor
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FYI. There isn't a GPA-UK.. the A is for American made usually AMA spec. The UK version is 209GP or now the UK= 211 GP (N-tec) or US being 211 GPA.

The N-tecs 211 GPs are more expensive, but last longer, maybe as much as twice as long..


Not responsible for incorrect data...its Cinco De Mayo-drink tequlia day!:D
 

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They have been using 190/55 & larger tires on the 600 Race bikes for many years now and even club racers were shaving 1-1.5 seconds off their lap times with the larger tires (> 180/55)

Just because you lack the experience, skill or ability needed to discern the difference in tire size or how it relates to the overall geometry set-up or available traction does not mean there is "really nothing to gain".

Maybe you should try riding a current 600 instead of that old worn out antique 750 and you might realize how crappy MR. RC45 really is. :)

If the RC45 was a vagina it would look like two soggy strips of bacon smashed together and surrounded by some 70's bush.

Ding Ding Ding we got a winner!
 

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V4 CyclePath...
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I race a 600 with a 190 rear. I recently switched to Dunlops from Pirelli. I did not like the soft carcass of the Pirellis- too much feedback. I also found that the Dunlops last alot longer.
 

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Discussion Starter · #19 ·
I race a 600 with a 190 rear. I recently switched to Dunlops from Pirelli. I did not like the soft carcass of the Pirellis- too much feedback. I also found that the Dunlops last alot longer.
Socal, did you have to adjust any thing as to ride height when you switched from Pirelli to Dunlops?

I switched away from Dunlops cuz I called to get a quote, they told me a set of Ntec shipped to me is about 525. That sound very high and Pirelli is about 100 cheaper.
 

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Craft Int Instructor
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Well the D GPA's are around $400.. They are a great tire, the Ntec's just last a little longer.
 
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