The Dark Side (Revisited)

[VulcanV2K]

Originally Posted by RowdyRed94

Interesting. You didn't, however, test the passenger car tire that's at the heart of this matter. The SP5000 is no doubt a softer compound.

RowdyRed94,

I don't understand your statement. I did research based on my circumstances so I could come to an intelligent decision based on the facts. I simply chose to compare the Battlax and the Dunlop because I now have both those tires, so this directly affects me. My Dunlop SP5000 is not some exotic tire. It is a normal V rated high performance car tire with a pretty average (for a high performance tire) 340 wear rating. My research shows that on average, motorcycle tires are made of much harder rubber compounds than car tires. This is either true, or false and I welcome anyone to produce actual facts that prove this as false.

One of the first things people rant about if they feel care tires on bike is a bad idea is the "fact" that bike tire are superior because they are made of much softer rubber compounds than car tires. Well, I am putting forward, based on actual research, the fact that the opposite is true. I have found that most, if not all, similar rantings are based on similarly false assumptions. I refuse to discount out of hand the thousands of people that have actually tried this. The fact that no one can produce any real evidence that this is dangerous or inferior is very telling to me. If anyone has ANY real information that this poses some real danger than they should present it. The repeated shouts that "the world is flat and no one will ever convince me otherwise" is a disservice to all of us that may be considering running a car tire.

The thousands of riders that have taken the time to try this and report their experiences does carry much more weight to me that those that continue to discount it based on what, feelings, misconceptions, incorrect "common knowledge"?? If you feel that car tires are a bad idea, please provide some kind of real information. The "Flat Earth" histrionics do no good at all. So, what does anyone think about this rubber compound information? Does it differ from what you thought?

[Clint]

What's with all the flat earth remarks?

I indicated that I was interested in your findings. How, exactly, did you perform the tests?

FWIW, my position all along was that there was little evidence to show that this was not dangerous, and that I wouldn't be able to tolerate the poor handling a square tire would provide. I've ridden on enough flattened motorcycle tires to know what it does to handling. You seem to be providing some evidence, so let's have it already. Enough with the drama.

[omegajim]

jim goes digging for the stinkin microwave popcorn.

do go on, I really want to see the "technological argument vs reality miles"

I would like to see 2 (or more) similar bikes one with the bike tire, one with the car tire and really see what the differences are.

[Jammin'John]

Originally Posted by omegajim

still waiting to see how the actual tire does over the long term test.

10,000 miles on my current DS 215/60.
20,000+ miles on current DS on Valk 205/60.

JJ

[VulcanV2K]

Originally Posted by Easy Rider

OK, fair enough. I wasn't aware that the discussion was about performance rated cage tires.

What you say about the reasons for faster wear on bike tires is absolutely true. It is also true that, compared to the average cage tire, the compound used for bike tires is softer. Compared to some cage tires, it is a LOT softer.

So, lets compare apples to apples. I contend that of tires in the same general class, the bike tire will always have a softer compound. I have no proof of that, just a gut feeling and 40 years of experience.

YMMV

Well, lets see. I thought we were talking about the car tires people are using on their heavy cruiser and touring bikes. From what I have read many of these riders use and recommend ultra high performance tires with the exception of the Goodyear Triple Tread. This is a very popular tire for some reason even though it has a very high wear rating and a very square profile. It would not be my first choice but many people say it performs well and even though it seem like a poor choice to me I have no reason to doubt the people with direct experience running it. Sure, there are some that would put on anything that would fit, but as a general rule the people that are running car tires and report the best performance and handling are using high performance tires, so that is what I used for my example. Once again, in my example, my bike tire had a 30% harder rubber compound than my car tire. But lets do a more general comparison. I found a site that tested eight brands of 60,000 mile car tires and determined that they all had durometer ratings of around 65. I think anyone would agree that 60,000 mile rated tires are at the upper end of wear ratings for car tires in general. I also found some durometer numbers on several popular street motorcycle tires, such as Dunlop E3 and Metzler 880 tires that show pretty consistent durometer ratings of around 72. I think this is a pretty fair "apples to apples" comparison of the same general class of tires.

To take it a little further the high performance Dunlop D207 has a durometer number of 57 and Avon Super Venom has a durometer number of 61. My Dunlop SP 5000 I used in my example has a durometer number of 50, but with a wear rating of 340 it is by no means the softest street car tire out there. Many high performance street tires like the Dunlop Direzza Sport Z1 that have durometer numbers in the low 40s.

So, in comparing apples to apples, I contend that of tires in the same general class, the bike tire will almost always have a HARDER compound. I don't need to rely on my gut feelings or years of experience as the facts are readily available to anyone willing to spend a few minutes on Google to research the facts. Anyone can choose to confirm or refute my contention, or just ignore it and continue on with their beliefs. I think facts speak for themselves.

Take Care

[Clint]

Again with the drama. Let's leave "beliefs" out of the discussion, eh? They're not relevant in a scientific discussion, and you'll be more credible without the attitude.

So, I've always been under the impression that treadwear ratings were left to the prerogative of the manufacturer. Is that correct? If so, durometer testing provides more usable data. I'm still curious how these readings are made, and whether there's any bias in the testing. It goes against reason that a tire you state is softer than a motorcycle tire actually lasts so much longer. Doesn't that strike you as odd, especially since the car tires tend to have much smaller tread blocks?

[VulcanV2K]

Originally Posted by RowdyRed94

What's with all the flat earth remarks?

I indicated that I was interested in your findings. How, exactly, did you perform the tests?

FWIW, my position all along was that there was little evidence to show that this was not dangerous, and that I wouldn't be able to tolerate the poor handling a square tire would provide. I've ridden on enough flattened motorcycle tires to know what it does to handling. You seem to be providing some evidence, so let's have it already. Enough with the drama.

The flat earth remarks are a very generalized opinion based on many the remarks I've heard over the years, on many different subjects, that happen to differ with the dreaded "common knowledge". It was not directed at you and I apologize for mentioning it in reference to your post.

I have varied interests and have found internet forums to be a wonderful resource over the years. The "care tires on motorcycles" debate is basically identical to hundreds of other debates on any number of internet forums. One example is over clocking computer processors. This was an unbelievably intense debate that had thousands of people on one side saying "Hey, I tried over clocking my processor and it really worked great. Boy, I have a much faster computer for the same money as the cheaper one! Here is how I did it!" and on the other side you had people who said things like "What, are you an idiot? Highly paid Intel engineers have determined that these speeds are set in stone. You know your data will die a horrible and fiery death if you try doing this and when your house burns down and kills your family your insurance company will deny your claim when they find out you're an over clocker!!. No one will ever convince me this works. It's common knowledge that only the expensive rated speed processors can be used!!!"

My point is that many people form their opinions from ideas that seem to make sense based on their experiences and "common knowledge". Often these ideas turn out to be completely wrong. The idea that motorcycle tires are softer and stickier than car tires is one of these ideas. All I did was spend a few minute on Google to determine, based on testing by apparently unbiased people that in general, the rubber compounds of motorcycle tires are harder than the compounds used in car tires. I found that across the board motorcycle tires are 10 - 15 durometer points harder when comparing similar performance level car tires. The information is out there, I have no reason to make it up and it is easily checkable by anyone.

Deciding weather using a car tire is a good or bad idea should be based accurate information and no one will come to a valid conclusion if they think motorcycle tires are much softer than car tires.

You seem to have made a decision that you "wouldn't be able to tolerate the poor handling a square tire would provide. I've ridden on enough flattened motorcycle tires to know what it does to handling."

Did you base this on thinking motorcycle tire are softer than car tires? If the opposite is true would it change your thinking at all? Could you consider that a car tire with a softer compound, nice conforming radial side walls and a relatively rounded profile (like my Dunlop SP5000) might not handle as badly as a hard rubber tire with a stiff sidewall that falls off the sharp edge of its flat wear pattern because it can't conform??

Thanks and sorry again about the flat earth remark.

[VulcanV2K]

Double Posted in error.

[Clint]

Originally Posted by VulcanV2K

Did you base this on thinking motorcycle tire are softer than car tires? If the opposite is true would it change your thinking at all? Could you consider that a car tire with a softer compound, nice conforming radial side walls and a relatively rounded profile (like my Dunlop SP5000) might not handle as badly as a hard rubber tire with a stiff sidewall that falls off the sharp edge of its flat wear pattern because it can't conform??

I think we're talking from two different worlds here. I've worked with enough tires of both persuasions to know that a car sidewall is never going to "conform" enough to duplicate what a sharply curved sportbike tire does in a hard lean (beyond, say, 40 degrees from vertical). Obviously, you aren't speaking to sportbike riders, but that's the perspective I have. Maybe my rejection of the idea of using a square car tire comes more from my demand for good handling (of the sportbike variety), and not from any real or perceived characteristic of the tires in question. I'm guessing we'd agree that a car tire is not suitable for a sporting application. I'm curious what your experience has been in that arena. Should you indicate that a car tire would work well on a sportbike, I'd be forced to dismiss you as completely loony.

[intimid8er]

[Easy Rider]

Originally Posted by RowdyRed94

Should you indicate that a car tire would work well on a sportbike, I'd be forced to dismiss you as completely loony.

Well this whole thread IS in the Roadliner conference......even though we went through a TON of discussion before that was ever really mentioned.
And this practice IS known as the Dark Side, probably for good reason.

The guys riding "land yahts" can put tractor tires on them for all I care.

I just think they should qualify their recommendations a bit so some idiot kid with an R bike doesn't try to put a car tread on IT.

I am rather curious, though, about what caused 2 apparently past regulars, who I don't remember even seeing in the past 6 months or so, to suddenly re-appear seemingly on a mission to preach the gospel of the "Dark Side"......and to bring a new guy along with them.

Forgetting for the moment whether or not the actual subject has any merrit, I can't figure what the motivation is to "stir the pot". I'm just baffled and am kind of sorry I got suckered into the "discussion" at all.

[VulcanV2K]

Originally Posted by RowdyRed94

Again with the drama. Let's leave "beliefs" out of the discussion, eh? They're not relevant in a scientific discussion, and you'll be more credible without the attitude.

So, I've always been under the impression that treadwear ratings were left to the prerogative of the manufacturer. Is that correct? If so, durometer testing provides more usable data. I'm still curious how these readings are made, and whether there's any bias in the testing. It goes against reason that a tire you state is softer than a motorcycle tire actually lasts so much longer. Doesn't that strike you as odd, especially since the car tires tend to have much smaller tread blocks?

Have you read what is being said in this thread? I think beliefs are THE issue. If someone makes a definitive statement, based admittedly on no other information than a gut feeling, and chooses to ignore empirical data otherwise, then they are by definition expressing a "belief". What do you find so provocative in that statement?

For your questions, durometer readings are made with a "scientific" instrument, i.e., a durometer. You hold the durometer against a rubber object as it plunges a pin into the object. A reading is obtained based on the depth of the penetration. I'm not sure bias comes into play as a durometer is a machine and the reading is what it is.

The fact that a softer car tire outlasts a harder bike tire is well within reason. Bike tires by their nature have a very small contact patch compared to a car tire. At any given time this contact patch may be several to many times larger on the car tire. The relative pressure on the small contact patch will much higher than the large contact patch. Over time the larger contact patch will run many miles longer that the small contact patch, even if it is a softer compound. That is simply the reason motorcycle tires wear out so quickly compared to a car tire. A car produces a much higher load on its tires than a bike and the car tire still lasts much longer on a car that a bike tire on a bike I guess some car tire have smaller tread blocks, but it has many more of them in contact with the road at any given time than a bike tire.

[tricker]

[VulcanV2K]

Originally Posted by RowdyRed94

I think we're talking from two different worlds here. I've worked with enough tires of both persuasions to know that a car sidewall is never going to "conform" enough to duplicate what a sharply curved sportbike tire does in a hard lean (beyond, say, 40 degrees from vertical). Obviously, you aren't speaking to sportbike riders, but that's the perspective I have. Maybe my rejection of the idea of using a square car tire comes more from my demand for good handling (of the sportbike variety), and not from any real or perceived characteristic of the tires in question. I'm guessing we'd agree that a car tire is not suitable for a sporting application. I'm curious what your experience has been in that arena. Should you indicate that a car tire would work well on a sportbike, I'd be forced to dismiss you as completely loony.

I think I was pretty clear that my discussion referred to "people running car tires on big, heavy cruiser and touring motorcycles". I mean we are talking apples to apples aren't we, at least I was. I never saw anyone mention trying this on a sport bike, or did I miss something.

[intimid8er]

Originally Posted by Easy Rider

I am rather curious, though, about what caused 2 apparently past regulars, who I don't remember even seeing in the past 6 months or so, to suddenly re-appear seemingly on a mission to preach the gospel of the "Dark Side"......and to bring a new guy along with them.

Forgetting for the moment whether or not the actual subject has any merrit, I can't figure what the motivation is to "stir the pot".

If you look at it this way.......


IT's a friggin' Conspiracy!!!!


It all makes sense!




(I bet they're all car tire salesmen too!)

[geoffsimpson]

UGH! This is weak. WHO CARES!

[Easy Rider]

Originally Posted by VulcanV2K

I think I was pretty clear that my discussion referred to "people running car tires on big, heavy cruiser and touring motorcycles".

I don't think that was clear at all. Not from you or anybody else......for at least 50 messages into the thread......and at least the first two posts that you made.

But Geoff is the one who finally got it right.

[geoffsimpson]

Originally Posted by Easy Rider

But Geoff is the one who finally got it right.

Put it on a t-shirt fellers, cuz it don't happen often

[Trapper]

That's a wrap.