First Time Darksider -- Unbiased Initial Opinion/Perspective

[Orygunner]

The June issue of Rider Magazine has a great article about car tires on bikes. There is scientific data, not just opinions. It is worth the read. People can do what they want on their bikes, just like not wearing a helmet. But I will not jeopordize safety for less than $100. It's like being in an airplane or a boat. Not many options when the $h!t hits the fan and you're at 10,000 ft or 10 miles out at sea. Please read the article. Tales From the Dark Side: Putting Car Tires on Motorcycles | Rider Magazine

No, the article didn't have any scientific data. It had statements from "experts" that it shouldn't be done, but no actual testing, data, or actual reasons WHY.

It was just one long opinion piece where the author got quotes from industry PR people to back his opinion, along with some poorly thought out and inaccurate examples and arguments.

I've been running a car tire (General Altimax HP) on the back of my '05 Vulcan 2000 for over 8k miles now, and I am extremely pleased with the traction, handling, and wear. And yes, I do turn corners, sometimes as hard and fast as the cornering clearance of my bike will allow, even under full throttle.

...Orygunner...

[agentfox1942]

Personally I think a point is being missed here. IF car tires were just as good or better than MC tires on motorcycles, then I would think car tire makers would be chomping at the bit to get at this market space. Part for part, motorcyclists spend way more than car people do on their rides (just look at the cost of something like highway pegs). And if the car tire makers did this, then they would advertise in motorcycle magazines. I get about 6 motorcycle magazine subscriptions a month and very little of the advertising is tires (just my observation) when compared to clothing, accessories, etc., combined. The fact is car tire makers won't do it cause of liability issues. It's like a pharmaceutical company off-labeling their drug.

[agentfox1942]

No, the article didn't have any scientific data. It had statements from "experts" that it shouldn't be done, but no actual testing, data, or actual reasons WHY.
It was just one long opinion piece where the author got quotes from industry PR people to back his opinion, along with some poorly thought out and inaccurate examples and arguments.
I've been running a car tire (General Altimax HP) on the back of my '05 Vulcan 2000 for over 8k miles now, and I am extremely pleased with the traction, handling, and wear. And yes, I do turn corners, sometimes as hard and fast as the cornering clearance of my bike will allow, even under full throttle.
...Orygunner...

Yes, you are correct. But I would take an "expert" opinion over someone that just wanted to save money and put a car tire on their motorcycle. Experts render their opinions all the time - in courts of law, medical cases, etc., and they are not disputed. Just my non-expert opinion.

[RKR0923]

Have around 3,000 on my CT including the Blue Ridge Parkway (twice). Handling is not an issue, unless your a 1st time bike owner maybe. As the saying goes...don't knock it till you try it.

[blacklung]

I have a 2008 900 Vulcan Custom. All i can say is i ran a Michelin Primacy 205-60-15 for 15,000 miles, did some burnouts, and i just recently installed a General Altimax HP Passenger Performance 215-60-15, made a 2600 mile trip, 9 days, and 6 states. Not had a bit of trouble from either. I go through a couple pair of boots each year due to my heals dragging, and i tend to fold the pegs up when riding hard.

[EWA]

Agent you make a very valid point with courts, it actually might be the biggest reason car tires aren't promoted, but I think thousands of riders logging millions of miles of seat time would constitute being experts also.

[agentfox1942]

Have around 3,000 on my CT including the Blue Ridge Parkway (twice). Handling is not an issue, unless your a 1st time bike owner maybe. As the saying goes...don't knock it till you try it.

Not knocking it. It never occurred to me to even try it. I would never put a motorcycle tire on a car.

[Pooker]

I keep reading the treads on this CT vs MT issue.
For starters, can someone tell me or give me some PROOF that riding a CT is dangerous!!!!
I know of many motorcycle riders who have went down riding a MT but I cannot tell you any that ride a CT.
Common, stop and think about it, when bike first came out they had flat tread pattern, basically a car tire. I remember mounting VW tires on my bike back in 70's. (they were free)
When they started racing them they had to develop special tires to hold the bike on the track, the motorcycle tire. (or tire for racing)
My two bikes are cruisers and not a rice bike. 90% of all my riding is at a right angle to the road so I do not need a rounded soft compound MT.
What are the options here,........all bikes are not created equal,.....they have off road tires for off road bikes, they have road tires for racing bikes and that leaves cruisers, there are no tires for type of bike other than a car tire!!!
so I say again, can any one give me some proof that running a car tire on a bike is dangerous!

[agentfox1942]

Pooker, you are correct in your statements. I've been reading about it on a lot of other places, and I've learned this: Way back when, like you mentioned, there were car tires on motorcycles, but bikes were small, 45 cc harley's were common. 500 cc bikes were rare. Most people road locally, in nice weather. Bridgestone started making motorcycle specific tires way back in 1945. And it had nothing to do with racing. I can tell you this, my insurance (Progressive) and my previous insurer (allstate) both said all claims would be denied if an accident occurred and a car tire was on the bike. And there are specific tires for cruisers. Just check out Michelin. And I'm not a scientist, but I do have common sense. All anyone has to do is look at the videos posted on youtube and see the lack of tread that a car tire exposes to the road compared to a motorcycle tire that is curved and has tread up the side wall. Night and day.

[Orygunner]

Personally I think a point is being missed here. IF car tires were just as good or better than MC tires on motorcycles, then I would think car tire makers would be chomping at the bit to get at this market space. Part for part, motorcyclists spend way more than car people do on their rides (just look at the cost of something like highway pegs). And if the car tire makers did this, then they would advertise in motorcycle magazines. I get about 6 motorcycle magazine subscriptions a month and very little of the advertising is tires (just my observation) when compared to clothing, accessories, etc., combined. The fact is car tire makers won't do it cause of liability issues. It's like a pharmaceutical company off-labeling their drug.

First of all, motorcycle tires are a much smaller market than car tires.
Then consider the small fraction of riders that would even consider a flat-profile motorcycle tire, even if tested and approved by the manufacturers.

There IS absolutely no financial motivation for any tire manufacturer to put any money towards R&D of a flat-profile, super long-lasting motorcycle tire. They're doing their best to get long-lasting round-profile motorcycle tires, and competing with each other for that, but it's still a small market share of tires overall.

Even if they did come out with a flat-profile motorcycle tire, the cost would be much higher than a car tire, and those already running car tires wouldn't bother spending the extra money just for something that's been "approved" by a manufacturer.

The square profile motorcycle tire wouldn't necessarily work very well on all motorcycles, either. If you wanted, you can put a cruiser tire on a sport bike, or a sport bike tire on a cruiser, and each will work fairly well with advantages and disadvantages to each - but still good traction on either. Putting a car tire on a cruiser with limited lean angles appears to work very well, but putting a car tire on a sport bike really hasn't been tried much, and I have doubts about the car tire's ability to "flex" enough to keep a good contact patch on the ground at very high lean angles.

And of course, there's no reason for any manufacturer to put any money towards testing car tires on motorcycles either. They're in the business to make money, not test things for no financial gain.

There would be big liability issues without that testing, too. If someone who doesn't know how to ride buys a new motorcycle and crashes it because "the bike wouldn't turn," they've got gobs of testing data showing how motorcycles perform with motorcycle tires. If they came out and said "Yeah, it probably works fine," without any testing to back it up, and someone who doesn't know how to ride crashes a bike with a car tire, how are the manufacturers going to defend their statement in court?

Bottom line, there's no financial motivation for any manufacturer to test car tires on motorcycles, or even R&D to create a flat-profile tire for motorcycles. The only way for this issue to actually be scientifically tested would be a) motorcycle magazines, or b) some rich individual to pay for testing.

...Orygunner...

[agentfox1942]

...Orygunner... You're missing the point. There wouldn't be a need to spend the money to "develop" motorcycle tires if car tires were safe and recommended for motorcycles. They car tire manufactures could stop there motorcycle specific sub-divisions and reap the money from the motorcycle world just on their car tires. If they could prove their normal car tires were safe and proven on motorcycles, the gain is in the R&D savings. Your argument is unsound. "Even if they did come out with a flat-profile motorcycle tire" - it would be a motorcycle tire. It would be one tire. Less manufacturing costs, less R&D, etc. Jeez, why is there a bazillion different car tires, aren't they all the same? You wouldn't run a deep-tread mud tire on the highway year round. It's just like a motorcycle tire. Specific needs are met by one that couldn't be met by another.

[Orygunner]

Pooker, you are correct in your statements. I've been reading about it on a lot of other places, and I've learned this: Way back when, like you mentioned, there were car tires on motorcycles, but bikes were small, 45 cc harley's were common. 500 cc bikes were rare. Most people road locally, in nice weather. Bridgestone started making motorcycle specific tires way back in 1945. And it had nothing to do with racing. I can tell you this, my insurance (Progressive) and my previous insurer (allstate) both said all claims would be denied if an accident occurred and a car tire was on the bike. And there are specific tires for cruisers. Just check out Michelin

I used to be with Progressive, and I asked them the same question a couple of years ago: would my bike still be covered in an accident if I had a car tire mounted to the rear? They said absolutely it would.

Since I switched to GEICO recently, your comment sparked me to make sure that they would cover it too. So I called them (800-442-9253), and they also said that accidents would certainly be covered with a car tire mounted on the bike.

I even called Allstate (800-255-782, and they said coverage would be no problem at all with a car tire mounted on a motorcycle.

So either every insurance agent I've spoken to at three different companies lied to me, or whoever you spoke to lied to you.

...Orygunner...

[Orygunner]

...Orygunner... You're missing the point. There wouldn't be a need to spend the money to "develop" motorcycle tires if car tires were safe and recommended for motorcycles. They car tire manufactures could stop there motorcycle specific sub-divisions and reap the money from the motorcycle world just on their car tires. If they could prove their normal car tires were safe and proven on motorcycles, the gain is in the R&D savings. Your argument is unsound. "Even if they did come out with a flat-profile motorcycle tire" - it would be a motorcycle tire. It would be one tire. Less manufacturing costs, less R&D, etc. Jeez, why is there a bazillion different car tires, aren't they all the same? You wouldn't run a deep-tread mud tire on the highway year round. It's just like a motorcycle tire. Specific needs are met by one that couldn't be met by another.

The argument is sound. It would still cost money for testing to approve a car tire on a motorcycle (for liability), money that they would never regain in sales.

There's also the matter of rim size. Motorcycle and tire rim bead sizes are slightly different diameters. This sometimes requires higher air pressure than recommended to seat the car tire on the motorcycle rim. There's some tips and tricks to get it to seat easier, but there have been some tire failures reported trying to seat the bead (no failures using the tire after seating the bead, as far as I know).

They never COULD approve a car tire on a motorcycle rim because of that small difference. So they would have to manufacture a completely different set of flat-profile tires just for motorcycle rims. This would require money to develop and manufacture, for a tiny niche market that really won't sell enough to make up the cost.

To suggest tire manufacturers would drop motorcycle tires is silly. On average, motorcycle tires work best on motorcycle tires. However, there's some great advantages (and few disadvantages) of a car tire on SOME motorcycles, such as heavy cruisers like mine (Vulcan 2000). I have more traction, 4-5x the mileage, smoother ride, and equally as good, if not better handling with my car tire (General Altimax HP) than I did with the Metzler ME880 Marathon that wore out in 4500 miles, on MY motorcycle.

Disadvantages? The only real disadvantage to a car tire on my bike is that it handles worse on uneven surfaces. It tends to "wallow" in the bottom of highway ruts more than the motorcycle tire did, and low speed maneuvering on rough, uneven pavement gets a little dicey. Because when only one side of the tire goes over a bump, it wants to lean the bike the other direction away from the bump. Same thing in highway ruts, if you go towards one side of the rut, it wants to lean you back into the rut. This is really pretty minor considering the advantages, and not really too hard to anticipate and adjust to it.

Your last line makes my argument for me... My specific needs are a rear tire that doesn't wear out every 4-5k miles that provides excellent traction and handling. I got it in a car tire. Saving 10x the money is just a bonus. I am considering trying an Avon Cobra in the rear when this car tire does wear out. It will be interesting to see how it handles different, whether traction is as good as the car tire, and how long it lasts.

...Orygunner...

[agentfox1942]

Motorcycle and tire rim bead sizes are slightly different diameters. This sometimes requires higher air pressure than recommended to seat the car tire on the motorcycle rim. There's some tips and tricks to get it to seat easier, but there have been some tire failures reported trying to seat the bead (no failures using the tire after seating the bead, as far as I know).

This right here means you shouldn't do it if it does not meet the intended purpose.
And if you only got 4500 miles from a ME880, somethings wrong. I have the same tire on my Vulcan 1600 Classic and have over 12,000 on my meztler and it's still good. As far as the insurance goes, I can only state what I was told and what my policy states: "any modification to the insured vehicle not in compliance with manufacturers specifications will render coverage null and void" The agent said this is like what happened to the SUVs that were rolling over with Good Year tire troubles. Lawsuits were filed everywhere.

[RKR0923]

Why would anyone even say, Hey Mr Insurance guy...are you gonna cover my accident when the lady pulled out in front of me? I do have a car tire on my bike you know.....how stupid. Is the cop gonna look at your rear tire, like he knows. $500 says my agent has no clue what a CT looks like on a bike and I damn sure aint gonna say oh wait..Look! Matter of fact, I inspected my tire top to bottom, No Where does it say "Car Tire"....its just a "Tire"

[agentfox1942]

yup you're right. Ride on, darksiders!! ride on

[Uncle Wulf]

It's a lot of work, a lot of down time & not guaranteed to work.

Down time, yes. Think winter project here. It does take about a week to do it right. It ain't much work. Not as bad as repairing a tube by the side of the road would be. As for reliability, I've done lots of them. On my bikes, and my friends'. Never had it fail.

[KahWahSahKey]

yup you're right. Ride on, darksiders!! ride on

I plan to as soon as my current tire is worn out.

And you know what? I've got spokes so I'll be running a CT on my Vulcan 1500 Classic with an inner tube.

Booga booga booga!

[RKR0923]

guess u can't delete on here
The Dark Side

[RKR0923]

Pretty good reading here The Dark Side