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Discussion Starter · #1 ·
Of course there is the ongoing debate of a 180 series rear tire ruining the SVs handling. I'll just say this, it has slowed down the turn in speed but by no means has it "ruined" it. Anywho, the effect that I'm wondering about is the height of the tire itself. By switching from a 160/60 to a 180/55 has the rear ride height changed? Logically I would think it was lowered seeing as how the aspect ration went from 60 to 55, but I'm not very well informed on that topic. I'm looking to return to my original set ride height that I had with the 160 tire, cause my front end feels slightly less responsive than before. Could I drop the forks a few more mm to compensate for the rear tire? Enlighten me please.
 

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Eagle one
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I know this rpm/diameter calculator is for car tires..... but it should give a rough idea......

http://tech.oldsgmail.com/axle_RPM.html

Using 165/60 vs. 185/55 ..... it look like the 180 is just a tiny bit taller, which is what I figured it would be....

24.7" dia vs. 25.00" dia
 

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Discussion Starter · #3 ·
So it's a quarter of an inch taller (basically)...I should raise the forks in the triples then to compensate. They are already dropped 10mm...it's going to take some weekend fiddling to get things back to how I liked them.
 

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The second number is the ratio. You've got a tire 160 mm wide and if it's 160/60, then it's height is .60 of 160 mm or 160 x 0.6 or 160 x 60%. 180/55 is 180 mm wide and 180x.55 mm high.

What GTONut posted was diameter, not radius. Diameter is the width of the entire tire, so you're looking at a .3" change across it's total height from ground to top. That means a change of half that, or .15", in the actual height of the axle relative to the ground, assuming tread depth, inflation, yada yada are all constants (which they aren't, but what the heck). That's a bit under 4 mm ( 3.81 ).
 

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Discussion Starter · #5 ·
Red Raevyn said:
The second number is the ratio.   You've got a tire 160 mm wide and if it's 160/60, then it's height is .60 of 160 mm or 160 x 0.6 or 160 x 60%.     180/55 is 180 mm wide and 180x.55 mm high.

What GTONut posted was diameter, not radius.  Diameter is the width of the entire tire, so you're looking at a .3" change across it's total height from ground to top.   That means a change of half that, or .15", in the actual height of the axle relative to the ground, assuming tread depth, inflation, yada yada are all constants (which they aren't, but what the heck).  That's a bit under 4 mm ( 3.81 ).
Excellent, thank you.
 

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A smaller rim will make the tire pinch in the middle causing the tire to be even taller. A 180 is made for a 5.5 rim, 170 you can use a 5.0 rim. People were doing this same thing when the first CBR 600's came out. tring to put a bigger tire on them little rims caused all kinds of crashing. The edge of the tread was getting way to steep to corner safely on. But for posers it was ok, cause they never went out of town, never leaned over so they got away with it. I would never run a tire bigger than a 160/60 on my 4.5 rim, I tried it on my 650 Hawk GT over 10 years ago. And I lost performance. same turn, same speed with the bigger tire I was sliding when I never slide before. And their heavier. Bad Bad Bad ! And that would be lowering the forks/raising the triple clamps, to raise the front end. FYI---jd  ::)
 

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Discussion Starter · #7 ·
Jimmie said:
A smaller rim will make the tire pinch in the middle causing the tire to be even taller. A 180 is made for a 5.5 rim, 170 you can use a 5.0 rim. People were doing this same thing when the first CBR 600's came out. tring to put a bigger tire on them little rims caused all kinds of crashing. The edge of the tread was getting way to steep to corner safely on. But for posers it was ok, cause they never went out of town, never leaned over so they got away with it. I would never run a tire bigger than a 160/60 on my 4.5 rim, I tried it on my 650 Hawk GT over 10 years ago. And I lost performance. same turn, same speed with the bigger tire I was sliding when I never slide before. And their heavier. Bad Bad Bad ! And that would be lowering the forks/raising the triple clamps, to raise the front end. FYI---jd  ::)
No....lowering the forks lowers the front end, and vica versa, there was nothing about lowering the forks to raise the front end. I know the 180 is slightly pinched on the 5.0 rim, and I also know alot of racers that use the same setup. Heavier? Don't care.
 

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evilbologna said:
No....lowering the forks lowers the front end, and vica versa, there was nothing about lowering the forks to raise the front end. I know the 180 is slightly pinched on the 5.0 rim, and I also know alot of racers that use the same setup. Heavier? Don't care.
Lowering the fork raises the front end and raising the fork lowers the front end - it's relative to the triples. With the triples, lowering them lowers the front end and raising them raises the front end.
 

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Discussion Starter · #9 ·
zoltan said:
Lowering the fork raises the front end and raising the fork lowers the front end - it's relative to the triples. With the triples, lowering them lowers the front end and raising them raises the front end.
Well its how ya think about it, in my head when I think lowering the forks I'm thinking how the triple is in comparison to the fork, the triples are lower on the forks. Lowering the tubes themselves in relation to gravity, yes thats different but not what I meant.
 

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zoltan said:
Lowering the fork raises the front end and raising the fork lowers the front end - it's relative to the triples. With the triples, lowering them lowers the front end and raising them raises the front end.
 +1   Hey zoltan, thanks for the support. It's always been lower the forks raise the front end in my world ::)              
 
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