Going to the Dark Side

[Wolfhound]

If you search enough you will find the info on car tires being wrong on motorcycles and insurance companies willing to bring their expert witnesses to court. I do have 45 years riding street experience & have seen plenty of car tires on motorcycles sliding thru intersections and hardly having control in corners, does that count ? Oh, and common sense too . . . :blum: .... Maybe not too common though :lol: (All in jest but true)

 

[OGRE]

I've been watching this thread since the beginning. I decided to wade in with my opinion. I'm a certified accident reconstructionist and I have several years of experience with working accidents of all shapes and sizes.

Most accidents are caused by the driver not the vehicle.If you know your vehicle's limitations and drive with-in those parameters you won't have a problem. If you drive a 4x4 truck, you can't expect to win a race with a formula 1 car and if you drive a formula 1 car you can't expect to drive off road. If you buy(or convert your normal cruiser) into a 12 foot long chopper, you can't expect to carve up the twisties with the sport bike crowd. By the same token if you put a car tire on an FJR you MUST adjust your expectations of the performance of the bike. If you can drive with-in the performance envelope of your modified vehicle it's just as safe as any other motorcycle.

If you need a super high mileage tire and are willing to accept the trade off of reduced handling go for it!!!!

 

[Bustanut joker]

Damn! I think ORGE here made sense.... several valid points. But...

I still say,

YER BALLS ARE GONNA FALL OFF!!!!!!!!!

:jester:

 

[user 213]

One of the best statements so far in this thread:

Any "safety issues" would be the result of outriding the tire's capabilities, and those same issues come into play whichever tires you mount. Understand the tire's limits and ride within them, and it's all a wash. Nearly any farkle changes the bike's performance envelope. How much that change is worth is subjective.

Well put Palerider. Ogre made a similar statement, also well stated.

Exactly the point of this exercise, to find out if the limits I ride within, are within the limits of the CT. Not to find the limits of the CT. A significant difference.

I do have 45 years riding street experience & have seen plenty of car tires on motorcycles sliding thru intersections and hardly having control in corners, does that count ?

Well, since you asked. Not really. Here's the thing, I've seen plenty of motorcycles sliding through intersections and hardly having control in corners too. None of them were on car tires. It's the rider, not the bike/tire/etc.

Heck, I only have 90,800 miles on this FJR with moto tires to use as a standard for handling. I might need Bustanut's help to determine if the CT handles as good as, worse than, or just different than a normal moto tire. :huh: And then there's the whole debackle of does it handle worse than a Chen Shen, or just worse than a ME880, or is it really only about the same as a Conti RA? :derisive:

If you haven't tried it, don't knock it. To say it can't work, when it clearly does work, well that's just silly. I've already proved to myself that it fits, works fine, is different to a lesser degree than I expected, but isn't for everyone. I've tried to share that info as openly as possible. I'm not on a crusade to convert anyone. Neither am I so simple minded as to be convinced by someone with no direct experience that I'm endangering myself just because they can't believe it might actually work.

The real beauty of this thread is none of you need stress yourself with the idea of trying a CT, you get to watch me do it for FREE! And read all about the results.

Now if it would stop raining for a while so I can get more riding it, I'd give you more input. I've got some great roads I want to ride locally that will give me a much better idea of how well, or how poorly the CT will do in the fun twisties. But there isn't much point in doing it wet.

 

[ian]

I was looking at a CanAm Spyder today. The front tire's profile seems to be a cross between a MC and a CT. Unfortunately they were on 14" rims. I didn't think to look at the brand until after I was back on the road. Wonder if these are made in other sizes? Ian, Iowa

 

[user 213]

I was looking at a CanAm Spyder today. The front tire's profile seems to be a cross between a MC and a CT. Unfortunately they were on 14" rims. I didn't think to look at the brand until after I was back on the road. Wonder if these are made in other sizes? Ian, Iowa

The CanAm uses car tires. Specifically, Kumho Solus KR21s. Kumho Solus

From the website: "Created for drivers of domestic and imported sedans, minivans and wagons, the Kumho Solus KR21 provides high levels of handling and grip while maintaining low noise levels throughout the life of the tire. Utilizing Kumho.s newest compounding technology, improved wet, dry and snow traction make the SOLUS KR21 the perfect choice for a wide variety of vehicles and drivers."

It's an all season 85,000 mile rated tire. Holy crap, 85k!? They use 14" in front and 15" in the rear. The Bridgestone all season tire I chose doesn't have a mileage warranty. I was told to expect around 20-30k on a car application. Another interesting item from the CanAm web site specs is that they use 13-17 psi in the front tires and 26-30 psi in the rear.

FWIW, I'm currently using 32 psi. Still playing around with that.

I just went and looked, Tire Rack sells the KR21 as a Grand Touring All Season tire. $107 in 205/50-17 and it looks like it will fit fine. Lighter than the 019Grid I have by a few pounds too. Still, I didn't want a tire rated for 60k+ for several reasons. They usually have very hard, square tread designs. You could probably put one of these on and never wear it out. I wonder if this means the CanAm Spyder is hard on tires?

 

[VaFJRrider]

[SIZE=14pt]Wow man, your concept is definitely thought provoking and crazy, but I am a little that way to.... I would like to ride it myself just to experiment a little... if you were in Virginia, I'd come and check it out.... good luck and hang on [/SIZE]

 

[Flylooper]

Well. I took off the caliper strut on my bike yesterday and am going to a fabricator guy to see if he can make me a version of it in 1/4-inch stainless steel, which should allow the Potenza to be used back aft.

The journey begins. I'm following in OCFJR's footsteps.

Here's a thought I had while reading through some of these doom and gloom posts about lack of braking, sliding through intersections, and all the rest. I'll throw out this hypothetical question, which (deviously) should keep this little discussion going for a few more posts....

If you're running a MC tire in back and, in the middle of any kind of turn - at speed - if the rider hits the rear brake hard it's a pretty good assumption he's going down in a low side. With a CT in back, the same thing happens. The rear end breaks out in both scenarios.

If you hit the rear brake hard in a straight line stop you'll stay up but you'll just skid. A lot. So let's consider the straight line emergency braking scenario:

If the contact patch on a 8.5-inch CT is great then the 1-inch patch on a MC tire, is it not logical to assume that the braking power in the CT is greater than on the motorcycle tire?

Variables:

1. Weight/sq. inch of contact patch and the effect of same on friction with the roadway

2. Tire compound. The "stickiness" of the tire to the road and its effect of friction.

3. Does the bigger contact patch on the CT overcome any of these variables?

Discuss: [as I pour myself another cup of joe]

Show your work.

 

[RadioHowie]

Show your work.

BWAHAHAHAHAHAHAHAHA!!!

Um, Mister Looper....I gotta go to the bathroom. Can I get a hall pass please?

Personally, I think a major slam on the rear brake on a CT-equipped bike is going to cause a reverse-stoppie, i.e., the torque of the forward momentum of the motorcycle will be converted into DOWNWARD movement and the front wheel, forks and triple tree are going to be forced down IN to the pavement, like a big-assed, 145HP RotoTiller.

Shortly to be follwed by the rider, of course.

But seriously, logic (what? here on the fjr forum?) tells me the increased contact patch of a CT should dramatically improve the rear braking performance, thereby making that pedal in front of the right foot peg more than a glorified hill-holding mechanism at stoplights.

 

[Flylooper]

Show your work.

BWAHAHAHAHAHAHAHAHA!!!

Um, Mister Looper....I gotta go to the bathroom. Can I get a hall pass please?

Personally, I think a major slam on the rear brake on a CT-equipped bike is going to cause a reverse-stoppie, i.e., the torque of the forward momentum of the motorcycle will be converted into DOWNWARD movement and the front wheel, forks and triple tree are going to be forced down IN to the pavement, like a big-assed, 145HP RotoTiller.

Shortly to be follwed by the rider, of course.

But seriously, logic (what? here on the fjr forum?) tells me the increased contact patch of a CT should dramatically improve the rear braking performance, thereby making that pedal in front of the right foot peg more than a glorified hill-holding mechanism at stoplights.

I think I agree with you. "A" for the day. And here's the pass. Be back in 5 minutes.

 

[v65]

If you're running a MC tire in back and, in the middle of any kind of turn - at speed - if the rider hits the rear brake hard it's a pretty good assumption he's going down in a low side. Show your work.

Well I don't care what kind of tire you run, that's your business, but I think this is a load of crap. I've put the binders on pretty hard on the front tire in a turn with Storms mounted, no problemo. Sometimes it pays to run sticky tires.

 

[palerider]

Well. I took off the caliper strut on my bike yesterday and am going to a fabricator guy to see if he can make me a version of it in 1/4-inch stainless steel, which should allow the Potenza to be used back aft.
The journey begins. I'm following in OCFJR's footsteps.

Here's a thought I had while reading through some of these doom and gloom posts about lack of braking, sliding through intersections, and all the rest. I'll throw out this hypothetical question, which (deviously) should keep this little discussion going for a few more posts....

If you're running a MC tire in back and, in the middle of any kind of turn - at speed - if the rider hits the rear brake hard it's a pretty good assumption he's going down in a low side. With a CT in back, the same thing happens. The rear end breaks out in both scenarios.

If you hit the rear brake hard in a straight line stop you'll stay up but you'll just skid. A lot. So let's consider the straight line emergency braking scenario:

If the contact patch on a 8.5-inch CT is great then the 1-inch patch on a MC tire, is it not logical to assume that the braking power in the CT is greater than on the motorcycle tire?

Variables:

1. Weight/sq. inch of contact patch and the effect of same on friction with the roadway

2. Tire compound. The "stickiness" of the tire to the road and its effect of friction.

3. Does the bigger contact patch on the CT overcome any of these variables?

Discuss: [as I pour myself another cup of joe]

Show your work.

So the CT might in some instances make riding safer? Take THAT you doom-and-gloomers!

Hmmm--now you've got me thinking that for straight-up touring we should be using CTs for both front and rear. h34r:

 

[SouthernCruizer]

I've also been watching this thread with interest. I have decided to do a "reverse test" of the moto vs car tire. I am taking my Pontiac Formula Firebird to the tire shop today and mounting 4 Avon Storms on it! I will report back and let you know how well the car did with moto tires. I just hope my front end doesnt wobble or otherwise track or wear strangely. :glare:

 

[Flylooper]

I've also been watching this thread with interest. I have decided to do a "reverse test" of the moto vs car tire. I am taking my Pontiac Formula Firebird to the tire shop today and mounting 4 Avon Storms on it! I will report back and let you know how well the car did with moto tires. I just hope my front end doesnt wobble or otherwise track or wear strangely. :glare:

Should work out okay. Just keep a damn good balance in your checkbook. You'll need one.

After a few replacement episodes, you'll be trying out something made for a Peterbilt.

 

[Fred W]

Even if the contact patch is larger assuming the total weight of the bike is unchanged, then the weight per square inch of contact area will be less with the CT. The total amount of force has to stay the same.

 

[El Toro]

I know that this thread was consciously brought back from Never Ending Pointless Recurring Threads because a moderator :big_boss: thought that it was not recurring.

There should be a new catagory, Never Ending Pointless ******** Threads. NEPRT. :butcher:

One thing is sure.... NEVER ENDING :help:

A second thing would probably be agreed on by the majority..... POINTLESS :to_become_senile:

And you know, with its current category, this is one of those threads where every post adds to your count, if you care.

:jester:

 

[RadioHowie]

Even if the contact patch is larger assuming the total weight of the bike is unchanged, then the weight per square inch of contact area will be less with the CT. The total amount of force has to stay the same.

Trying to wrap my head around what you're saying -- do you mean that a contact patch of a car tire, say 16 square inches (2" x 8") is no better than the contact patch of a motorcycle tire, say 4 square inches (2" x 2")?

...that given an emergency (lock-up) situation a car tire wouldn't stop faster than a motorcycle tire?

Or are you simply saying that for any given amount of equal pressure applied to the brake pedal, the car tire wouldn't provide any better stopping power than a bike tire?

Professor Looper DID say

So let's consider the straight line emergency braking scenario:

Just tryin' to understand the point you were trying to make.

 

[FJRay]

I think Eric deserves some kind of award for entertaining us during the winter months and showing how many people with so little knowledge are willing to pontificate about things unknown.

And it does help the post count. :yahoo:

 

[palerider]

I think Eric deserves some kind of award for showing how many people with so little knowledge are willing to pontificate about things unknown.

Is this a great country, or what?

 

[v65]

And it does help the post count. :yahoo:

Exactly.