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 Car Tire on Back of Vulcan 1700??
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USMarine6173
Male Standard Member
102 Posts


Moline, Illinois
USA

Yamaha

V-Star 650

Posted - 08/15/2013 :  11:06 PM                       Like
Group:

A gentleman I work with put a regular car tire on the back of his Vulcan 1700. After doing a triple take, I asked him how that was working out for him -- especially around corners??

I don't think he appreciated the question because his reply was: "Why don't you hop on and find out?!"

My question(s) for the group are the following:

1) Why would someone put a car tire on their bike? (Cheap a-s maybe?)
2) How is he able to corner (safely) with an angled contact patch and sidewalls not designed for this?
3) How would a car tire on a bike handle at high speeds?

I'm sure there are other people who have done this (or contemplating it) and when they do a google search of the pro and cons thereof, perhaps they will find this post?

Thank you in advance for your insight/perspective.

Edited by - USMarine6173 on 08/16/2013 5:14 AM

SkootchNC
Male Advanced Member
1062 Posts
[Mentor]


raleigh, north carolina
USA

Harley-Davidson

road glide

Posted - 08/16/2013 :  4:53 AM
google "dark side"... they have a forum on Delphi.

I'll stick to putting motorcycle tires on my motorcycle, and car tires on my car.

I know a few riders who have done so... and they all say the same thing "once you are used to the handling".... I've never had to adjust to the handling of a new motorcycle tire...

I do know riders who tried and didn't like... as well as riders who swear by them.
Most of the comments I've read by "dark-siders" is of the "if you haven't tried it, you don't know what you are talking about" variety...

I am not one to save money on tires or brakes... I'll shop around for the best prices, on top quality items... but I avoid the cut rate cheapo stuff
as always YOUR miles may vary
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Magnawing
Male Senior Member
281 Posts


The Woodlands, TX
USA

Honda

VF750C

Posted - 08/16/2013 :  7:57 AM Follow poster on Twitter
I haven't tried it, nor have I ridden a bike with a car tire on it. However, I do understand mechanical loading and the limitations of certain products in situations they weren't designed for.

Car tires have much thinner sidewalls than tread areas and a squared profile because they are designed to ride "flat" on the road. On the other hand, motorcycle tires have heavier sidewalls and a rounded profile because they are designed to lean into turns. By side loading a car tire when leaning into a turn, you risk failure of the thin sidewall causing a catastrophic blowout in the middle of a turn...while you're leaned over.

I'm with Skootch on this one...I'll stick to good quality motorcycle tires for my bike and leave the car tires on the cars. (they're called CAR tires for a reason)

But to answer your questions...

1) Who knows what goes through some people's brains?
2) He can't (see above)
3) It will probably handle highway speeds quite well...in a straight line...throw in some curves and well....see above (again)

Edited by - Magnawing on 08/16/2013 8:01 AM
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scottrnelson
Advanced Member
6949 Posts
[Mentor]


Meridian, ID
USA

Honda

XR650L, 790 Adv R

Posted - 08/16/2013 :  9:04 AM
quote:
Originally posted by SkootchNC

I've never had to adjust to the handling of a new motorcycle tire...

Apparently you haven't tried enough variety of motorcycle tires.

When I switched from IRC GP-110 tires to Continental TKC-80 tires on my Honda, there was some adjusting to the different handling. The TKC-80 is designed more for dirt and squirms a bit at speed in corners. It doesn't give you the same confidence leaning into a corner.

A month or so back I switched tires on my KTM from a more street-oriented tire to a 50/50 street/dirt Hiedenau K60 shown in the photo below. Those also handled differently and just feel different when riding. The bike is less smooth, and slow speed steering feels different. Those are two different sets of tires that required me to get used to their handling.





On a separate issue, I disagree with the sidewall argument. Look at the sidewalls on a 190/50-17 sport bike tire. You'll have a hard time finding a thinner sidewall on most cars. I also doubt that there is any evidence at all to "catastrophic blowouts in the middle of a turn".

I don't believe car tires are a good idea on a motorcycle, but let's stick with arguments that we can support, please.
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Magnawing
Male Senior Member
281 Posts


The Woodlands, TX
USA

Honda

VF750C

Posted - 08/16/2013 :  9:25 AM Follow poster on Twitter
quote:
On a separate issue, I disagree with the sidewall argument. Look at the sidewalls on a 190/50-17 sport bike tire. You'll have a hard time finding a thinner sidewall on most cars. I also doubt that there is any evidence at all to "catastrophic blowouts in the middle of a turn".

I don't believe car tires are a good idea on a motorcycle, but let's stick with arguments that we can support, please.



Maybe my wording was a little out of context...let's try this...

Motorcycle tires are designed to take the side loading created by leaning into turns. Car tires are designed to keep the contact patch relatively flat and are, therefore, manufactured with a more squared profile.

I retract my statement (though not my belief) about sidewall blowouts.

Here's a good read on the subject (the good stuff is at the bottom, after the diatribe about the response he got when posting to the Goldwing Forum)

http://en.allexperts.com/q/Motorcyc...torcycle.htm

Seems to be some good info on the linked site (almost as good as here)
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USMarine6173
Male Standard Member
102 Posts


Moline, Illinois
USA

Yamaha

V-Star 650

Posted - 08/16/2013 :  4:03 PM
I found out that a local motorcycle shop installed the car tire -- or so he claims? Can't see a bike shop taking on that kind of liability.

I wonder if the local dealer (I take my truck to) would install a motorcycle tire if I made the request?
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scottrnelson
Advanced Member
6949 Posts
[Mentor]


Meridian, ID
USA

Honda

XR650L, 790 Adv R

Posted - 08/16/2013 :  4:20 PM
quote:
Originally posted by USMarine6173

I wonder if the local dealer (I take my truck to) would install a motorcycle tire if I made the request?

It takes the same tools, but they probably wouldn't be able to balance it.
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rayg50
Male Moderator
2083 Posts
[Mentor]


NYC, NY
USA

Honda

Shadow Spirit 750DC

Posted - 08/16/2013 :  5:05 PM
quote:
Originally posted by USMarine6173


I'm sure there are other people who have done this (or contemplating it) and when they do a google search of the pro and cons thereof...

This is a much discussed topic. Google "dark side motorcycle tire" and you will have plenty of articles to choose from. Here is one:

http://www.ridermagazine.com/browse...rcycles.htm/
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scottrnelson
Advanced Member
6949 Posts
[Mentor]


Meridian, ID
USA

Honda

XR650L, 790 Adv R

Posted - 08/16/2013 :  5:30 PM
I'm thinking that it's about time for one of the motorcycle magazines to do some testing on a race track, using the same bike and making laps with both a quality motorcycle tire and whatever is considered to be the best car tire to use on the back of that bike.

Run about 10 laps on the track with each, keeping track of best lap times, worst lap times, and overall lap times. The rider could also point out any strange handling observed during the ride.

Either the lap times would be similar with no strange handling being observed, or the car tire would be way slower and there would be serious handling problems.

I would expect such a test to put an end to this argument once and for all. Either it would prove that car tires work just as well as motorcycle tires on some big bikes, or it would prove that they're a bad idea.

I wonder what it would take to convince one of the magazines to try this?
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USMarine6173
Male Standard Member
102 Posts


Moline, Illinois
USA

Yamaha

V-Star 650

Posted - 08/16/2013 :  7:43 PM
The test tract idea (using the scientific method) would put an end to the debate. For good measure though, put some water and oil on the track, along with some sand and gravel.

I wonder if the cyclist's insurer would pay a claim after they found out a car tire was on the bike?
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rayg50
Male Moderator
2083 Posts
[Mentor]


NYC, NY
USA

Honda

Shadow Spirit 750DC

Posted - 08/16/2013 :  8:38 PM
quote:
I wonder if the cyclist's insurer would pay a claim after they found out a car tire was on the bike?
That is the closing thought in the article that I provided the link to. The author wonders if using it would make one the target of lawsuits by "others injured in a crash". I think the next question in that thinking is would the insurance company bother to fight a suit when the legal fees would be greater than just cutting the check for their liability? By that I mean if you have 10k in insurance and legal costs were going to run well above that, IMO, the no brainer decision for the insurance company is to cut a check and walk away.

I've lurked on a few of the discussions in my bike specific forum and the common wisdom there is that chain driven bikes can be reasonably modified to take a car tire, shaft driven bikes not so much. It seems that since the tire is wider it can interfere with the path of the chain or the drive. A certain amount of off setting of the tire must be done to allow a clear path. In other words it is generally not as simple as popping one tire off and popping another tire on.


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CaptCrash
Male Advanced Member
744 Posts
[Mentor]


Nampa, ID
USA

Honda

Phantom

Posted - 08/16/2013 :  8:40 PM
Darksiding is about belief as much or more than operating costs. Darksiders are not swayed by argument because they operate from passionate belief. Akin to hardcore conspiracy buffs Darksiders will refute just about any argument with:

"Sure, that's what the tire industry wants you to believe"

Backed up with a dose of:

"I've done it for years and never had a problem."

If you want the experience just google "darkside motorcycle forum" and sit on porch and read for a while.

It's not full on crazy town but there's a lot of passion.
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SkootchNC
Male Advanced Member
1062 Posts
[Mentor]


raleigh, north carolina
USA

Harley-Davidson

road glide

Posted - 08/16/2013 :  9:38 PM
quote:
Originally posted by scottrnelson

quote:
Originally posted by SkootchNC

I've never had to adjust to the handling of a new motorcycle tire...

Apparently you haven't tried enough variety of motorcycle tires.

When I switched from IRC GP-110 tires to Continental TKC-80 tires on my Honda, there was some adjusting to the different handling. The TKC-80 is designed more for dirt and squirms a bit at speed in corners. It doesn't give you the same confidence leaning into a corner.

A month or so back I switched tires on my KTM from a more street-oriented tire to a 50/50 street/dirt Hiedenau K60 shown in the photo below. Those also handled differently and just feel different when riding. The bike is less smooth, and slow speed steering feels different. Those are two different sets of tires that required me to get used to their handling.





On a separate issue, I disagree with the sidewall argument. Look at the sidewalls on a 190/50-17 sport bike tire. You'll have a hard time finding a thinner sidewall on most cars. I also doubt that there is any evidence at all to "catastrophic blowouts in the middle of a turn".

I don't believe car tires are a good idea on a motorcycle, but let's stick with arguments that we can support, please.



I have NO doubt that "dirt tires" or "semi-off road tires" would effect my motocycled handling.... but I doubt I could find one that would support my bike.
Street tire to street tire.... from the OEM Dunlop D-402, to the Metzler Marathon, to the Dulop Elite-3, to the Michelin Commander II....there was no "once you get used to it"
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capozzir
Senior Member
303 Posts


Leesburg, VA
USA

Honda

GL1800B

Peer Review: 1

Posted - 08/22/2013 :  12:27 PM
quote:
Originally posted by USMarine6173

Group:

A gentleman I work with put a regular car tire on the back of his Vulcan 1700. After doing a triple take, I asked him how that was working out for him -- especially around corners??

I don't think he appreciated the question because his reply was: "Why don't you hop on and find out?!"

My question(s) for the group are the following:

1) Why would someone put a car tire on their bike? (Cheap a-s maybe?)
2) How is he able to corner (safely) with an angled contact patch and sidewalls not designed for this?
3) How would a car tire on a bike handle at high speeds?

I'm sure there are other people who have done this (or contemplating it) and when they do a google search of the pro and cons thereof, perhaps they will find this post?

Thank you in advance for your insight/perspective.



I have chosen to use car tires on my GL1800. So that probably makes me a loony but I tried to answer your questions as straight forward as I could without any passionate bias.

1) Some do it because they are less expensive. Some do it because car tires provide a softer ride. Others are looking for more weight capacity. I did it because I got tired of the rear motorcycle tires failing on me. I had 3 tires from 2 different manufacturers fail on me. Plenty of tread left but all of a sudden the tire would deform. Best case resulted in a slight vibration to worst case a large bulge developed. Fortunately I was close to home and able to get a new tire. A bit of a ticking time bomb in my experiences on my bike. All the tire had signs of heat damage. I do run the bike at the manufacturers GVWR limit but I'm not excessively over it by any means. The rear tire load limit however I may be over by as much as 50lbs due to the rear bias of weight distribution on the bike when I'm touring with my wife. I run the tires at the recommended pressure and have TPMS to monitor it. The moto tires just didn't seem to be heavy duty enough for my application. So, I tried a Run Flat car tire (which has just as thick or thicker a sidewall as a mototire and is about the same cost).

The car tire runs about 40% cooler in similar conditions to the moto tire based on my observations via my TPMS. And after 65k miles on 3 different RF car tires (still on my 3rd one) I've not experience one issue. No blow outs, not worn down sidewalls, they all wore down to the tread indicators nice and even. It only took me 24k miles to have those three moto tires fail on me. My current tire is an actual winter tire and after 22k miles I still have 6/32 of tread left. Not to bad.

2) Large cruisers and touring bikes don't have enough lean angle available to ride on the side wall of a car tire if enough air pressure is used. Non run flat tires with their thinner sidewalls require quite a bit more air than a run flat tire. 44psi would be what is needed for most non-run flat car tires on a GL1800 where 31psi is enough on a RF for me.

Maybe at extreme lean angles you might see with a sports bike on a track you could get over far enough to run the side wall. Don't know. I wear my engine guards out long before I was able to have enough lean angle to reach the side wall on a car tire.

The only sidewall damage I've seen from running a CT was do to rubbing issues (fitment issues) or an under-inflated tire run very aggressively in the corners.

3) Car tires are DOT rated and come in various speed ratings. I've run both H and V rated tires and both operate just fine at speed.

Just like moto tires, car tires all have very different characteristics. Some work better than others. I also install my own tires and other than the very stiff sidewalls of the RF, they install just like any other tire. The bead of the car tire fits just fine in the bead area of the 16" motorcycle rim of a Wing. I only need about 30-40psi to set the bead which is similar to the motorcycle tires. I can't speak to the 17" and 15" rims out there.

Hope this is helpful in answering your questions.
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scottrnelson
Advanced Member
6949 Posts
[Mentor]


Meridian, ID
USA

Honda

XR650L, 790 Adv R

Posted - 08/22/2013 :  1:06 PM
quote:
Originally posted by capozzir

I have chosen to use car tires on my GL1800. So that probably makes me a loony but I tried to answer your questions as straight forward as I could without any passionate bias.

[...]

Hope this is helpful in answering your questions.
Thanks for sharing that with us. Yours is one of the most informative posts I've seen on this subject.

Out of curiosity, what is the recommend motorcycle tire size and what is the car tire size that you're using?
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greywolf
Male Moderator
1484 Posts
[Mentor]


Evanston, IL
USA

Suzuki

DL650AL2

Posted - 08/22/2013 :  1:44 PM
I know some people who are happy with car tires on 17" V-Strom rear wheels. It's not for me but can be good for some users.
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TonicBIA
Male Senior Member
382 Posts


Arlington, Va
USA

Triumph

Sprint ST

Posted - 08/23/2013 :  3:06 PM
As a sidecar enthusiast, I love running car tires. So- it's an niche reason for throwing a car tire on, and it has nothing to do with lean. However, the sidecar puts extra stress on tires causing faster wear. Since I'm keeping them flat to the ground (most of the time ) they provide longer lasting and cheaper alternatives to motorcycle tires.
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capozzir
Senior Member
303 Posts


Leesburg, VA
USA

Honda

GL1800B

Posted - 08/27/2013 :  8:17 AM
quote:
Originally posted by scottrnelson

quote:
Originally posted by capozzir

I have chosen to use car tires on my GL1800. So that probably makes me a loony but I tried to answer your questions as straight forward as I could without any passionate bias.

[...]

Hope this is helpful in answering your questions.
Thanks for sharing that with us. Yours is one of the most informative posts I've seen on this subject.

Out of curiosity, what is the recommend motorcycle tire size and what is the car tire size that you're using?



Thanks Scott.

The OEM motorcycle tire is 180/60R16. The car tire is a 195/55R16. The total width of both tires (shoulder to shoulder) is nearly identical. The CT might be a tad wider (1/16" if that). The CT just appear wider since they don't have a rounded tread surface.

The diameter of both tires is also extremely close. In the picture, you can see the circumference measurement between the MT and CT. The CT measured 76" and the MT 75 5/8". You'll see that much variation just between MT brands that are "the same size".

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Gryphon Rider
Male Junior Member
45 Posts


Calgary, Alberta
Canada

Honda

Valkyrie Tourer

Posted - 08/28/2013 :  10:06 PM
I have a decent amount of street riding under my butt, earning my MC endorsement in 1990, and was a senior instructor for a local riding school for a number of years. My current ride is a Valkyrie, which I bought new in 2001, and which currently has 101,000 km on the odometer. After wearing out two rear tires, I put the first car tire on the back, a Falken Ziex 512, at 43,000 km. I replaced it with a General Altimax at 88,000 km.

Now to answer USMarine6173's questions:
1. Reports were that those who used car tires on their Valkyries were getting twice the miles at half the cost of the best motorcycle tires. The handling differences as described seemed to me to be worth risking the expense of a car tire to see if I was bothered by these differences. I also thought it looked cool to have that fat tire back there. It's also fun to watch the Nervous Nellys of the motorcycle community get their panties in a bunch when they see my tire.
2. I am able to corner safely because a tire is designed to flex, and even in a corner my rear contact patch is probably no smaller than with a motorcycle tire. I have never felt any squirminess, let alone slippage, with the car tire, other than during hard first gear acceleration while making a sharp turn, but I've experienced this with motorcycle tires as well. In a straight line, the car tire has MORE traction than the MC tire. I can and do comfortably scrape my foot pegs on twisty roads, and with the pegs limiting lean angle, I have never had the non-treaded part of the tire touch the road.
3. The squarer profile of the car tire DOES make the bike handle a little differently. With the bike tire I would push the bike into a corner, and once the lean angle was set, I needed zero net pressure on the bars to keep it leaned and turning. With the car tire, I need to supply a little pressure on the inside bar to keep it leaned. If I remove that pressure, the bike will stand up and ride a straight line. The other difference is that when the pavement is rutted or otherwise uneven from side to side, the bike will be pushed towards the bottom of the rut, or the low side of the unevenness. This is most noticeable at slow speeds, and I can't afford to ignore this effect. With all this being said, it did not take me long to get used to the differences.

Whenever I discuss this topic, I never try to convince anyone that a car tire is for them, but simply try to provide reasonable answers to what are often shrill objections voiced by those who quote "experts" who have never tried a (previously proven to work) car tire on a motorcycle.

I run 35 PSI in my non-run-flat tire, and currently use Ride-On in it for balancing and in case of puncture. I installed my current tire myself; what a pain, but worth it.
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