Stock rear wheel, if you go from a 190 tire to a little larger...

[BoostCreep]

I have more knowledge on cars and am still learning about motorcycles but...

Say a person on a stock 1g Hayabusa were to want to swap out to a 200 rear tire or a little bit larger. Would that increase contact patch or would that only change tire geometry and increase the circumference of the tire? The reason I ask is because the way a motorcycle tire is designed, it seems like they are only designed to fit whatever width wheel they are on which I assume give it these effects:

Too wide of a tire on a rim - The tire itself stands up too much, increasing circumference and changing riding characteristics, making it a little more happy to turn in and you wont really reach the edge of the tire.

Too narrow of a tire on a rim - The tire flattens out a little bit, decreasing circumference and setting the bike a little lower. The riding characteristic is changed and turn ins are slower. This I would think would be dangerous because it gives you a greater chance of actually rolling off the edge of the tire and wrecking pretty badly.

Contact patch in either situation - Contact patch remains relatively the same.

Is my line of thinking far off?

 

[rubbersidedown]

200 is as wide as it gets for a stock swing arm.

I believe the engineers know what they are doing with sportbikes these days and provide the best size possible right outa the gate.

I am trying a 180 right now on my twisties Busa. I have tried lots of combo's over the last 12 years/5 or 6 Busa's.

Unless U are a pro rider trying to lay down faster track times,I dont think it matters a whole fug of alot.

Me,I just like to experiment with all things Busa related...I can't ride for shi7.

RSD.

 

[Tufbusa]

I don't think you'd want to install more than a 200 series tire on a 6 inch rim. First you'd have to go to a wider swingarm and offset the chain and the issues wouldn't stop there.

The wider the tire the more negative impact on the "Effective" lean angle due to moving the contact patch farther away from the centerline of the tire. If you could put a bicycle tire on your bike it would corner faster at any given lean angle due to the contact patch being closer to the centerline of the bike.

However, a wider tire does have a larger contact patch which gives more grip for corner exits. The bottom line is there are no free rides, the wider tire gives more grip at the expense of corner speed.

 

[In10SS]

the height of the tire can be a factor as well. A 190/55 contact patch should be taller than a 190/50 when leaned over. Also, the taller/rounder tire makes the transition into a lean smoother and more progressive. A few years ago we had many debates of 180/55 vs 190/50 with the general consensus being that the smaller but rounder tire was an all around better performer. Now that 190/55 size is more common, it might be the best compromise around with the added benefit of raising the rear slightly and quickening the steering. A similar case could be made comparing the 190/55 to a 200/50. Note that brands vary in width as well. Some of the 200's are very close in size to other 190's.

 

[Amode]

No your thinking is right on. Check out the Pirelli angel GT. Look and see what they did to the profile.

 

[1busa]

Whats the purpose your wanting a larger tire for? You going for looks or just wanting to try something new?

 

[BoostCreep]

Whats the purpose your wanting a larger tire for? You going for looks or just wanting to try something new?

Actually I have no desire to change wheel or tire size. I've got some time off work at the moment and I'm studying how suspension settings, geometry, and tire pressures affect the tire itself. In the middle of it, I was thinking of how the tire itself is built and what would happen if the wheel size were to remain the same and the tire size itself were to change (if those were the only two factors). Just having some fun and poking for opinions.

Amode - Thanks, I'll look that up here in an hour or two.

 

[jellyrug]

I don't think you'd want to install more than a 200 series tire on a 6 inch rim. First you'd have to go to a wider swingarm and offset the chain and the issues wouldn't stop there.

The wider the tire the more negative impact on the "Effective" lean angle due to moving the contact patch farther away from the centerline of the tire. If you could put a bicycle tire on your bike it would corner faster at any given lean angle due to the contact patch being closer to the centerline of the bike.

However, a wider tire does have a larger contact patch which gives more grip for corner exits. The bottom line is there are no free rides, the wider tire gives more grip at the expense of corner speed.

IMHO a wider tire, or larger contact patch does not give more grip, in fact due to heat build-up at some point the narrow tire will give more grip and beyond that point with excessive heat build up it may have less grip. A smaller contact patch will generate more tyre heat and wear faster than a larger contact patch. At exactly the same rubber temperature, both will give exactly the same grip.

 

[kml]

IMHO a wider tire, or larger contact patch does not give more grip, in fact due to heat build-up at some point the narrow tire will give more grip and beyond that point with excessive heat build up it may have less grip. A smaller contact patch will generate more tyre heat and wear faster than a larger contact patch. At exactly the same rubber temperature, both will give exactly the same grip.

WHAT!!!! SURFACE AREA IS NOT PROPORTIONAL TO FRICTION? Yeah right, Look buddy the layman's assumption is more area = more grip, so get with the program. Amontons' Laws of Friction be dammed!



cheers
ken

 

[MEBusa]

I went from a 190 stock Bridgestone, to a 200 Avon Storm Ultra 2. I didn't do it for the technicals, but solely for the "wider tire" look. Yes I can see a difference in the 190 & 200. My rear looks just a little more beefier, than the 190 I had.

 

[jellyrug]

WHAT!!!! SURFACE AREA IS NOT PROPORTIONAL TO FRICTION? Yeah right, Look buddy the layman's assumption is more area = more grip, so get with the program. Amontons' Laws of Friction be dammed!



cheers
ken

LOL

I believe Leonardo da Vinci was the first one to really figure that out in the 15th century and about 400 years later some high schools were teaching it in grade 10, with lab work to convince the students.
The first folks who really figured out how and why a bike turns were the Wright Brothers in North Carolina, late in the 18th century and we still argue about it more than 100 years later.

 

[Flicka]

LOL

I believe Leonardo da Vinci was the first one to really figure that out in the 15th century and about 400 years later some high schools were teaching it in grade 10, with lab work to convince the students.
The first folks who really figured out how and why a bike turns were the Wright Brothers in North Carolina, late in the 18th century and we still argue about it more than 100 years later.

Wait just a minute... Are you saying my bike is capable of Wing Warping?!?

 

[Tufbusa]

IMHO a wider tire, or larger contact patch does not give more grip, in fact due to heat build-up at some point the narrow tire will give more grip and beyond that point with excessive heat build up it may have less grip. A smaller contact patch will generate more tyre heat and wear faster than a larger contact patch. At exactly the same rubber temperature, both will give exactly the same grip.

Boy Howdy, I have no idea what comic book you got that out of?

 

[chrisjp]

if size of contact patch dont matter...why do drag racers reduce their tire pressure?

 

[jellyrug]

Boy Howdy, I have no idea what comic book you got that out of?

Read post 9 above and read post 11 above. If you still disagree, lets talk about it further, but the rule is you have to be nice.

The storybook, was grade 10 in high school, with lab work and briefly in Mechanical Engineering 1st year college, as at this stage we were expected to know.

 

[Tufbusa]

Read post 9 above and read post 11 above. If you still disagree, lets talk about it further, but the rule is you have to be nice.

The storybook, was grade 10 in high school, with lab work and briefly in Mechanical Engineering 1st year college, as at this stage we were expected to know.

Now who says I have to be nice. I call a spade a spade.

You may be a mechanical engineer but your knowledge about motorcycle tires is a bit fuzzy.

 

[m_ridgeway]

Are we really about to argue whether contact patch effects traction?

 

[kml]

Assuming that the surfaces are comprised of the same material (tire compound and pavement) and assuming they are equal temperature and the force (weight)pressing them together is the same, the friction generated is the same regardless of surface area contact.

Regardless of the common assumptions of the motorcycling community ((Tufbusa)) and tire manufacture babble this is BASIS physic and has been proven for hundreds of years.

Laws of dry friction

The elementary properties of sliding (kinetic) friction were discovered by experiment in the 15th to 18th centuries and were expressed as three empirical laws:
Amontons' First Law: The force of friction is directly proportional to the applied load.
Amontons' Second Law: The force of friction is independent of the apparent area of contact.
Coulomb's Law of Friction: Kinetic friction is independent of the sliding velocity.

cheers
ken

 

[black diamond busa]

Are we really about to argue whether contact patch effects traction?

They have run out of things to argue about can't you tell

 

[jellyrug]

Now who says I have to be nice. I call a spade a spade.

You may be a mechanical engineer but your knowledge about motorcycle tires is a bit fuzzy.

Darn, and I was looking forward to an intelligent discussion?