CL350 Super wide wheels and tires?

[AlphaDogChoppers]

Not sure why someone would want them aside from the looks.

Well, "Duh!"

My daughter rides a Suzuki GZ250. The front tire for that bike is a proprietary size that Dunlop makes exclusively for Suzuki, and the Suzuki dealer is the only place to get it. The cost is over $200! Fuck that! I put a Kenda Cruiser tire on it that was 10 mm narrower, and the handling was improved. The OEM tire size is for a "fat tire" look, not for handling.

 

[Sonreir]

I tell you what, man. When a tire company tells me that I need bigger tires for better performance you can be sure I'm gonna pony up the extra cash because they definitely have my best interests at heart. ;D

 

[561design]

There's absolutely nothing wrong with going up a little in width AS LONG AS the rim width goes up to match. Guys get shitty handling when they slap a fat tire on on a stock skinny rim. Perhaps a better answer to the OP's question should have included a caveat that rim width has to increase too. And appropriate profile selection to keep stock tire height...which will affect rim selection again...

I for one would appreciate a larger contact patch afforded by wider tires, and I fully plan to source wider rims this coming winter.

I'll bet that FZ/CB handles just fine.


EDIT: I'm of course not talking about chopper or 'busa builders who go waaay too far.

Ringo, can you talk to the implications of rim width and tire height? I'm interested in "incrementally" increasing the contact patch as well.

 

[561design]

Fitting fat tires to old slow bikes with flexy frames is nonsense just to impress the straight acting homos with celtic armband tattoos in front of the local Starbucks.....It makes them handle like crap and be potentially lethal.....Oh and they are plenty worse to ride.....

If you want a cool looking bike with fat tires get a Vmax,a TW200 or a Harley bagger.....Polaris quad with 22"ers?

That's a little much isn't it? There is a threshold of performance when it comes to increasing tire AND wheel/rim width. To Ringo's point, performance significantly declines when one item (tire) is increase and the other component is not (rim). That aspect ratio between the two items needs to remain constant in order to prevent a drastic decline in performance. And to your point, if you go too far, you can also lose performance. But there is nothing to be said about increasing the width of tire and rim incrementally. Because I can assure you that you don't know, nor do the the racers that you posted. They're running with what they know what works and through trial and error. Unless you test with variables in a controled environment, you'll never know the truth.

Now, onto tire widths that were issued at the release of these motorcycles. That tire ratio to displacement or rather output was determined by the manufacture based on current testing methodologies at that time. I can assure you there has been significant understandings that have been learned the telemetry and other methods since the 60's. With that said, it is entirely possible to incrementally increase tire AND rim while performance remains at parity. There is even the possibility that a slight increase can be seen if other variables on the motorcycles have been changed.

Your arguement is only valid if all variables remain constant and that currently is not that case. Tire compounds have improved and most bikes have different levels of output now than they did when they first rolled off the line. Those two things alone should really change your perspective on the subject.

 

[AlphaDogChoppers]

Your arguement is only valid if ...

Swivel doesn't need a valid argument to hurl insults, innuendo, and vitriol...

 

[Ringo]

Swivel doesn't need a valid argument to hurl insults, innuendo, and vitriol...

And that's why I find myself warming up to the guy. ;D

Ringo, can you talk to the implications of rim width and tire height? I'm interested in "incrementally" increasing the contact patch as well.

Well, contact patch varies widely by tire make, so that's kind of irrelevant. As you go up in width, if you keep the same profile, say a 110/90 to a 120/90, your tire height will increase. That's because the profile (90) is a percentage of the width, on metric tires. If you want to keep the stock height, which you should for geometry and speedo error, you'll need to find out what profile you'll need for your chosen width.

Also, as you go down in profile, you'll need to go wider in rim width, again. Squeezing a 120/80 tire on to the same rim that you'd mount a 120/90, will pinch the sidewall more, affecting handling. Not much different than going from a 110/90 to a 120/90 on the same rim. But somebody else may be better equipped to answer your question at this hour as I still need my coffee. Just know that width AND profile go hand in hand as far as selecting your rim width.

And I didn't catch it before, but when you say "Super wide".....I think we're on two different wavelengths. I'm talking about a SLIGHT increase in width, not slapping a 180 tire on the rear.


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[Sonreir]

There are instances where a slightly wider tire will be beneficial to performance, but I believe that WAY too much emphasis is placed upon this concept of bigger-is-better when it comes to contact patches.

The fact remains that the mathematical formulas for calculating friction have literally nothing to do with contact area and everything to do with the materials used and the forces (in this case, gravity) holding the two objects (tire and pavement) together. As your contact patch expands, the weight placed upon the tire becomes spreads out of a larger area and so the frictional force on a square centimeter basis decreases. Real world example: 100 Newtons placed upon a small piece of rubber in contact with pavement will have the same frictional forces as 100 Newtons placed upon a large piece of rubber provided that the rubber and pavement remain constant in all of their properties.

Furthermore, a larger tire may not actually increase your contact patch unless you end up with a softer compound. It's possible that many folks attribute their increased grip to the wider tire and not to the new rubber being used. When you choose a wider tire of a similar construction and compound, the contact patch remains roughly the same because the weight being placed on the tire and the tire's ability to deform both remain the same. This means your contact patch doesn't increase, it just changes shape. It will become wider from side-to-side and narrower front-to-back. At first, one may believe this to be a beneficial change when it comes to cornering, but actually it isn't. As you lay the bike over for a turn, get the tire onto its side, you're automatically introducing slippage into the frictional formula because the inside/top of the tire is closer to the center of the wheel than the outside/bottom of the tire. Slipping surfaces have less friction than static surfaces, this is easily demonstrated by the differences in effort of pushing something from a stop as opposed to pushing it once it's already moving, inertia aside. And so because the inside if your contact patch has a smaller radius than the outside of your contact patch and the tire is seeking to travel at a uniform rate of rotation, slippage or deformation of the contact patch occurs. Not a good thing when it comes to seeking maximum grip. With a more narrow tire, the contact patch remains wider in front-to-back measurements and helps to minimize slippage in turns.

As for the benefits of big tires, it boils down to this:
1.) Wider tires are more stable at high speeds
2.) Going ultra-soft on rubber compounds necessitates using wider tires just to keep the structural integrity of the tire within safe and usable limits

If you have the choice between a wider tire and a thinner tire of the same compound and high-speed stability is not a concern, there is no performance benefit in choosing the wider tire.

 

[Deviant1]

I'm sorry... What were we talking about here? I got lost about eight paragraphs back... Was it boots? Or lady avatars? I don't know, but i have a headache...

 

[Ringo]

"Never trust your physics book for real world situations. Life doesn't involve frictionless surfaces and weightless ropes."

You said it yourself, Matt... A wider tire gives a shorter, but wider contact patch than a narrow tire, which gives a long but skinny contact patch. But here's what you didn't say... A shorter, wider contact patch is better for lateral grip, i.e. in corners! Don't believe me? Look it up, from people who know, not your book.

I'm not talking about handling, we know skinny tires give quicker handling. The fact of the matter is, in the real world, a larger contact patch will give more grip up to a point, all things being equal.

 

[Sonreir]

You said it yourself, Matt... A wider tire gives a shorter, but wider contact patch than a narrow tire, which gives a long but skinny contact patch. But here's what you didn't say... A shorter, wider contact patch is better for lateral grip, i.e. in corners! Don't believe me? Look it up, from people who know, not your book.

I didn't say it because I don't believe it to be true, not because I was intentionally omitting anything. The lateral grip is determined by the coefficient of friction and the normal force. What perhaps went unsaid is that the coeffcient of friction and the normal force can change based on load, suspension, etc.

Wider tires may be more forgiving because of their larger lateral contact patch and ability to absorb increasing slip angles (difference in inside and outside radius I mentioned earlier) but absolute maximum grip comes from a smaller contact area because it is less affected by slippage.

If we do wish to expand on your idea of the shape of the contact patch giving better lateral grip (which I'd be willing to conceed up to a point provided some more evidence is shown) then that same logic would dictate that narrower tires would be better for accelerating and braking during turning maneuvers due to their longer contact patch. True? So if you're able to accelerate and brake better in a corner with a narrower tire, then which is truly superior?

 

[ohiocaferacer]

 

[surffly]

 

[Sonreir]

I'm not talking about handling, we know skinny tires give quicker handling. The fact of the matter is, in the real world, a larger contact patch will give more grip up to a point, all things being equal.

I missed this part and I think it's important that it's addressed because you're totally right. I think part of the reason we're failing to reach a consensus that a wider tire doesn't mean a larger contact patch (I'm assuming that that's where you're coming from, please correct me if I'm wrong).

As I mentioned in an earlier post, a wider tire changes the shape of the contact patch, but doesn't necessarily change it's area. A larger contact patch comes from softer compounds and, at a certain point, softer compounds require wider tires. So the point I'm trying to make (sorry, just trying to clarify, not trying to beat a dead horse) is that grip and width should not be directly associated with one another.

 

[Ringo]

Luv ya, Matt. ;D We'll hash this out over a beer someday.

 

[Sonreir]

I got some brewing right now. ;D
You back in Oregon yet or still kickin' under the Big Sky?

 

[Ringo]

I love home brew! I'm back in MT for this summer, but will be making every effort to make it to The One show this winter...

 

[Nasty N8]

Thanks for the comments guys I do know the ins and out of what the sizes will do have been a mechanic for 20 years and road raced modern bikes. Not looking to do "clown shoes" or a 300 busa just some extra width to handle lean angle and hard riding. I have been trying to get the frame geometry closer to modern angles rake trail swing arm droop...and like the look of a sport bike with the retro. Building these bikes for fun and to ride the crap out of them.

Guess I understand it's not totally necessry but some extra lean angle control and wide rim look.

 

[crazypj]

Its not even about rim/tire ratios and fitments
Its about moving a contact patch further out from the centerline of a chassis and increasing the stress and flex on frames

This is 100% correct statement, when tyres get wider the contact patch moves sideways when your leaned over
Frame can easily get overwhelmed (flexing is common even with stock tyres)

 

[Sonreir]

And don't neglect a suspension upgrade.

 

[Deviant1]

Yep. Good oem sized roadriders were the best tire I have run on my cb750. Not cheap, but excellently sticky.