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YO MAMA
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Discussion Starter · #1 ·
hey dano can you help me out with this since we both are...lean angle twisty masters and wheelie freaks..lol

i dont know what to think right now untill...i get a warm day again to beat the shit out of it.


http://www.sportbikes.net/forums/showthread.php?s=&threadid=108269


i think its the new 180 tire...my last 2 190/50's M1s were fucken like nothing yanking it up OR clutching it up...and not with this 180M1 and its broken in HARD....140 miles on it...it wont come up as easy..(slipping?...sometimes i cant tell) OR can it be my clutch just got bad all of a sudden (over night without riding it?)
but if it is slipping (the clutch) i cant almost tell cause it STILL has that SNAP when i hit the gas even in 2nd gear which its a moster when i do...i honestly dont know what to think..but i think its this 180 tire.
and i am running 30 rear psi just like i use to with the 190's
(race pressure)
today i beat the shit out of it in highspeed sweepers and some tight stuff....NEVER ONCE gave me slip...BUT now i cant yank or more so CLUTCH it up?
weird
:confused :confused
 

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Odysseys said:
hey dano can you help me out with this since we both are...lean angle twisty masters and wheelie freaks..lol

i dont know what to think right now untill...i get a warm day again to beat the shit out of it.


http://www.sportbikes.net/forums/showthread.php?s=&threadid=108269


i think its the new 180 tire...my last 2 190/50's M1s were fucken like nothing yanking it up OR clutching it up...and not with this 180M1 and its broken in HARD....140 miles on it...it wont come up as easy..(slipping?...sometimes i cant tell) OR can it be my clutch just got bad all of a sudden (over night without riding it?)
but if it is slipping (the clutch) i cant almost tell cause it STILL has that SNAP when i hit the gas even in 2nd gear which its a moster when i do...i honestly dont know what to think..but i think its this 180 tire.
and i am running 30 rear psi just like i use to with the 190's
(race pressure)
today i beat the shit out of it in highspeed sweepers and some tight stuff....NEVER ONCE gave me slip...BUT now i cant yank or more so CLUTCH it up?
weird
:confused :confused
Ken we should go for a short ride and put a shoe polish mark on that back tire. You wheelie and I'll watch to see if it's tire spin or clutch spin;)
 

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YO MAMA
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Discussion Starter · #3 ·
huh?...never tried that..i think i know what your going for..and what to look at but never done it before..you got your bike fixed?

my brother in law just called me a few ago...to see if i wanted to go for a burn..if he is still home...i dont have my cell phone on me ..i left my wife use it today hers is on the shitter....so call me at [email protected]:30....ill PM you my home # if you dont have it...this is really bothering me to see what the fuck it is?
 

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Odysseys said:
huh?...never tried that..i think i know what your going for..and what to look at but never done it before..you got your bike fixed?

my brother in law just called me a few ago...to see if i wanted to go for a burn..if he is still home...i dont have my cell phone on me ..i left my wife use it today hers is on the shitter....so call me at [email protected]:30....ill PM you my home # if you dont have it...this is really bothering me to see what the fuck it is?

sprockets not here yet but I got an idea where we can do this close. Either that or I'll video tape it so you can see and we can slow it down. Call you in a few;)
 

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Odysseys said:
hey dano can you help me out with this since we both are...lean angle twisty masters and wheelie freaks..lol

i dont know what to think right now untill...i get a warm day again to beat the shit out of it.


http://www.sportbikes.net/forums/showthread.php?s=&threadid=108269


i think its the new 180 tire...my last 2 190/50's M1s were fucken like nothing yanking it up OR clutching it up...and not with this 180M1 and its broken in HARD....140 miles on it...it wont come up as easy..(slipping?...sometimes i cant tell) OR can it be my clutch just got bad all of a sudden (over night without riding it?)
but if it is slipping (the clutch) i cant almost tell cause it STILL has that SNAP when i hit the gas even in 2nd gear which its a moster when i do...i honestly dont know what to think..but i think its this 180 tire.
and i am running 30 rear psi just like i use to with the 190's
(race pressure)
today i beat the shit out of it in highspeed sweepers and some tight stuff....NEVER ONCE gave me slip...BUT now i cant yank or more so CLUTCH it up?
weird
:confused :confused
Well I doubt it's your tire if you've put miles on them. Cuz I know that you're a monster when it comes to scrubbing in your tires. LOL...
And actually a smaller tire (on a wide rim) gives you a wider contact patch. Why do you think that some of the drag racers run 160s on a 5.5/6 inch rim??
Anyhoo, if you're worried about you clutch slipping and you're not sure if it is or not. Get going about 45 mph or so. Put it in a higher gear( 5th or 6th) at a steady speed pull in the clutch, rev your bike, and then dump it. If the revs drop right away your clutch is fine. If they slowly drop (like the clutch is slipping) you're gonna need a clutch.
BTW there's no need for the clutch on a liter bike for 2nd gear wheelies....lol
Your tire isn't going to make a difference to over-all gearing (well a noticeable one). 180 as an aspect ratio of 55 and a 190 has a ratio of 50 so they are about the same overall size. The only thing I can think of is the difference between your old worn out tire being smaller (tread wear) compared to your new one?? Just give it more gas....haha
Good luck and if you have any more questions let me know
 

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YO MAMA
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Discussion Starter · #6 ·
thanks dano....actually yesterday it was a bit better...i honestly think its the colder temps now and colder roads...i gotta do that dump the clutch thing..maybe later today.

i tell yeah one thing though...keeping it in a stright line is harder now when holding a wheelie with a new 180 versus a flattened out 190:laughing

i could drink a pop before..now i would spill my pop while wheeliing...lmao


i still think my clutch is fine, but ill try that. i always thought though on a 180 rear the center was smaller on what ever size rim i got on the 9r..it does make sense what you said...but i though it was the other way around...hummm?...got me wondering now.

any how..pimps up and hoes around:laughing
 

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Odysseys said:
thanks dano....actually yesterday it was a bit better...i honestly think its the colder temps now and colder roads...i gotta do that dump the clutch thing..maybe later today.

i tell yeah one thing though...keeping it in a stright line is harder now when holding a wheelie with a new 180 versus a flattened out 190:laughing

i could drink a pop before..now i would spill my pop while wheeliing...lmao


i still think my clutch is fine, but ill try that. i always thought though on a 180 rear the center was smaller on what ever size rim i got on the 9r..it does make sense what you said...but i though it was the other way around...hummm?...got me wondering now.

any how..pimps up and hoes around:laughing

I used to think that putting a smaller tire on gives you a bigger contact patch too. I guess if you put a 160 on my rim it would, but there is something about these 180's that give it a more extreme contour over the 190. It really does make a smaller contact patch. I witnessed it riding behind Ken Yesterday. I also feel a huger difference in turn in time when I went to a 180 from a 190 on the R1. It threw all my theories about tires when drag racing out the window
 

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Well it does give you a wider contact patch only in the middle tho. On a wider rim. I'm NOT gonna run a 160 on my racebike....:rofl
My tip of day....


JUST GIVE IT MORE GAS......:cheers :cheers
 

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Evil Moderatrix,
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In rudimentary terms, a tire specifically designed for drag racing will have a profile more in common with Ken's old, flattened 190 than a new 180 street tire. Drag racing slicks are also run at lower pressures than a street tire, to accomodate changes in the tire's profile at speed (and retain an ideal traction "footprint").
 

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KBOlsen said:
In rudimentary terms, a tire specifically designed for drag racing will have a profile more in common with Ken's old, flattened 190 than a new 180 street tire. Drag racing slicks are also run at lower pressures than a street tire, to accomodate changes in the tire's profile at speed (and retain an ideal traction "footprint").

I'm with you Kim,

I think the 190's are just made more for drag racing with a flatter profile. The 180's for road racing with a more extreme contour. I'm sure if I tried to put a 160 or 170 on my rim it would be as flat or flatter than the 190 profile.
 

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I always kind of wondered what the actual tradeoffs are here:

Same bike + same rider = same weight

Same weight + smaller contact patch = greater lbs./sq. in. due to smaller area

Same weight + larger contact patch = lesser lbs./sq. in. due to larger area

So assuming a tire material with the same friction coeffecient, what are the tradeoffs?

The friction coefficient remains constant, how do variations in area versus pressure (downward force) work to determine TRACTION?

Another way of putting it:

When does the decrease in surface area become too small to overcome the increasing lbs./sq. in. of downward force, causing decreased traction?

Also, it doesn't seem intuitively obvious that you can use the diameter alone to detemine the contact patch. The tire's profile is also a factor. It is also not intuitively obvious that a smaller tire of the same profile is going to have a larger contact patch than a larger tire with the same profile.
 

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BusaDave said:
I always kind of wondered what the actual tradeoffs are here:

Same bike + same rider = same weight

Same weight + smaller contact patch = greater lbs./sq. in. due to smaller area

Same weight + larger contact patch = lesser lbs./sq. in. due to larger area

So assuming a tire material with the same friction coeffecient, what are the tradeoffs?

The friction coefficient remains constant, how do variations in area versus pressure (downward force) work to determine TRACTION?

Another way of putting it:

When does the decrease in surface area become too small to overcome the increasing lbs./sq. in. of downward force, causing decreased traction?

Also, it doesn't seem intuitively obvious that you can use the diameter alone to detemine the contact patch. The tire's profile is also a factor. It is also not intuitively obvious that a smaller tire of the same profile is going to have a larger contact patch than a larger tire with the same profile.

I'm not sure what your getting at Dave. I think that if your talking about straight line acceleration traction the more surface area that contacts the ground is going to decrease the amount of lbs/sq. inch but increase the rate of friction. That's why you see the big slicks on the dragsters. The smaller surface area tires most of us choose are chosen as a trade off for surface area on the sides when we lean them over.
 

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Evil Moderatrix,
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Also, it doesn't seem intuitively obvious that you can use the diameter alone to detemine the contact patch. The tire's profile is also a factor. It is also not intuitively obvious that a smaller tire of the same profile is going to have a larger contact patch than a larger tire with the same profile.
Exactly... which is why I was comparing street tires to drag racing slicks.
 

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Crazy said:



I'm not sure what your getting at Dave. I think that if your talking about straight line acceleration traction the more surface area that contacts the ground is going to decrease the amount of lbs/sq. inch but increase the rate of friction. That's why you see the big slicks on the dragsters. The smaller surface area tires most of us choose are chosen as a trade off for surface area on the sides when we lean them over.
Rate of friction???:confused

I'll expand more on this later when I'm at home.
 

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YO MAMA
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Discussion Starter · #15 ·
friction..there shouldnt be any friction unless you like it like that..but to me it always chaps my thing up...so i grab the vasaline and BAMM it strokes SMOOTH and soft...then its usually over withien a few pumps....we are talking about the same thing right?:laughing
 

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Odysseys said:
friction..there shouldnt be any friction unless you like it like that..but to me it always chaps my thing up...so i grab the vasaline and BAMM it strokes SMOOTH and soft...then its usually over withien a few pumps....we are talking about the same thing right?:laughing
:laughing :laughing :laughing NO!!!!


Dave, I'm going to try to explain this. I think that the numerical scientific formula's for friction are bit decieving in this situation. Compounds and materials play a role in the overall end result I think you're are getting at, which is what is the best contact patch size to have for maximum traction. The answer is simple. The bigger the contact patch the better the traction. More surface area lightens the pressure of your bike on the road but give you more area to create friction on. Obviously too big of a patch is going to take away from the actual profile of the tire and make it to hard to lean over. Like a drag slick.
 

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Ok heres the thing. when comparing a 190 to a 180. The 190 will have a rounder cross section than the 180 which in turn means less of a contact patch bacause the beads are squezing more rubber in between the rim lips which is the constant in this equation. The 180 has less rubber in between so it will have a flatter cross section meaning it will have more of a center contact patch. Now for rard racing and turning a 190 will be optimal since the side tread will be rounder due to the squeez affect of pressing that big of a tire on the rim. Ken for the type of riding you like to do I would think you would be much happier on a 190 maybe even a 200 since that would give you even a rounder cross section. and therefore more side surface to lean on.

If you want to see an extreme exaple of this just take any old tire off the rim and squeeze the beads together till thier about 3" apart. and watch how the shape of the cross section changes.

One more thing is a 190 and 180 will not have the same size sidewall because that middle number (i.e. 190/ 50/17 ) is not an actual measurement in MM as is the first number The 50 is only a percentage of the first number which makes up how many MM the sidewall will be. So 50% of 190 = size of sidewall in Millimeters.
 

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YO MAMA
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Discussion Starter · #18 ·
:confused i am still confused.

plain english.

which tire...180 or 190 has a greater center contact patch area

and which tire has a greater side wall contact patch area.

on the same rim..what ever a normal liter bike size rim is now adays.
 

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Lovin this Twin
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Ken


180 is for straight line............. more contact in the middle

190 for the curves.......... more contact on the outside edges
 
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