Topic: Why car tires?

[MJL]

Not exactly SOHC related, but I saw several videos on youtube where guys were running car tires. In some of the comments people said they would never go back to a motorcycle tire. What is so great about car tires on a bike?

[vanillagorilla]

These guys like to sit out in front of a bar and roast a tire for a minute, then ride straight down the highway to the next bar to repeat the process. Get it??? Car radials hold up a lot better to bar hopping buffoonery, but suck to turn on. Its just as weird as you would think it is. I installed one on a vtx1300 a couple of years back. The guy said the same thing, "Ill never go back"... Of course he won the burnout contest at the rally that weekend, so that probably had something to do with his enthusiasm.

[Gorms]

Lets see this video.

[lone*X]

My primary ride is an 1800 VTX and this subject is a hot one on any cruiser board.  My factory rear Dunlop 180/60r16 lasted about 5k miles.  I have now gone thru several BridgeStone BT020R 200/60VR16's and they are getting about 8 to 9k miles before I feel they need replacing.  Admittedly I am conservative where tires are concerned, which is why I don't do this.  Running a car tire is generally called going to the Dark Side, they even have a dedicated board for Dark Siders.  A car tire may get 30 or 40k miles on a bike due to several factors, like hard compounds, large contact patch, and the patch is flat.  Look at the flat strip down the middle of your round profile bike tire and it will be a few inches wide, that's your normal contact patch and it wears quickly.  Consider a car tire may have 4 or 5 times the contact patch the wear is much less.  For a long distance cruiser rider this all adds up to a considerable cost savings.  Big downside is that cornering and control suffer.  Think about going into a sweeper or fast S curve at 90mph and getting up on the knife edge of a square profile tire made with hard rubber, then transitioning from one direction back across the flat profile and up on the other edge.  Most Dark Siders discount the cornering and control issues as they are straight liners.  And of course they do like the reduced cost over the long run.  There are also a lot of guys that once they have tried the Dark Side they come back to real motorcycle tires.

Having rode a big variety of bike types and performance levels I can say with a lot of convection that the Dark Side is NOT FOR SOHC's!  

[nobody]

I googled "motorcycle car tire" because I couldn't quite visualize how one would look on a bike. I found this:

http://alaskajack.smugmug.com/Motorcycle-Rides/Winter-Riding/A-New-Challenge/2477376_NLJ8o#P-1-9

I guess they're rather useful in the snow, that's dedication to riding. I've ridden in temperatures well below freezing (12 degrees was my coldest, rather impressive that a cb750 will start that cold) but riding in the snow? In Alaska? That's a new level of nuts.

[754]

Depends a lot on how low your bike sits..
 Once it is slammed enough, to get it out of the hard cornering/lean angles, it matter less which tires you run..
 Now if you enjoy frequent burnouts/laying rubber, well now you can have your fun, at a much lower cost..

 mgab, why is it impressive that it would start.. .. why should it not start.. .. we used to run em in 0 fahrenheit on the ice quite a bit..

[nobody]

Well I had a vt1100 Shadow that wouldn't start in temperatures below mid forties, there was probably something wrong with it. My last three cars would struggle to start sometimes as the temperatures would get closer to zero too. I just was rather suprised when the cb started up that day.

[Gorms]

Heres a good video showing the side to side rolling of a car tire:
[youtube=425,350]<object width="425" height="344"><param name="movie" value="

name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="

type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>[/youtube]

[Magpie]

Lots of GL1800 Goldwing riders really like them, even on the Tail of The Dragon. Here's a thread from that site about it http://gl1800riders.com/forums/showthread.php?t=230611

[Gordon]

Heres a good video showing the side to side rolling of a car tire:
[youtube=425,350]<object width="425" height="344"><param name="movie" value="

name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="

type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>[/youtube]

That just looks wrong...

Car tires last longer because they're made of harder rubber, and because of this they don't stick to the road as well as motorcycle tires, but that's fine for cars because they have four of them, and one (or even all four tires) losing traction doesn't necessarily mean that the car is going to crash. 

Motorcycle tires wear out faster because they're made of softer rubber that grips the road much better.  I guess some will say that the increased contact patch of the car tire makes up for this, which it might in a straight line, but as this video shows, as soon as the bike leans into a corner, the contact patch is no bigger (and possibly smaller) than it would be on a motorcycle tire, therefore you will have much less grip at precisely the time that you need grip the most.

Most of these bikes I'm seeing car tires on are pretty expensive machines, being ridden by guys who probably don't blink at the thought of spending thousands of dollars on all the gear they're wearing, but then they decide to skimp on how much they're willing to spend on a freaking tire?  Arguably one of the most important pieces of safety equipment on a motorcycle?

The arguments I've seen that are pro car tires all remind me of the arguments from people who say it's safer to ride without a helmet.  It's a bunch of ignoring facts and common sense and all seems like rationalizations that are come up with after-the-fact to support a decision that was made for less than intelligent reasons.   

[754]

mgab, sorry I thought you were talking CB 750.. I dont use the estart, kick works well in cold weather..

 Car tires came into common use in the late 70s on 15 inch wheels on choppers, mainly due to wider widths, availability and price.

 Like I said, if you bike is low enough, it should not get you in trouble.. and way cheaper to light up the tire...

[Really?]

My primary ride is an 1800 VTX and this subject is a hot one on any cruiser board (That ain't no lie!).  My factory rear Dunlop 180/60r16 lasted about 5k miles.  I have now gone thru several BridgeStone BT020R 200/60VR16's and they are getting about 8 to 9k miles before I feel they need replacing.  Admittedly I am conservative where tires are concerned, which is why I don't do this.  Running a car tire is generally called going to the Dark Side, they even have a dedicated board for Dark Siders.  A car tire may get 30 or 40k miles on a bike due to several factors, like hard compounds, large contact patch, and the patch is flat.  Look at the flat strip down the middle of your round profile bike tire and it will be a few inches wide, that's your normal contact patch and it wears quickly.  Consider a car tire may have 4 or 5 times the contact patch the wear is much less.  For a long distance cruiser rider this all adds up to a considerable cost savings.  Big downside is that cornering and control suffer.  Think about going into a sweeper or fast S curve at 90mph and getting up on the knife edge of a square profile tire made with hard rubber, then transitioning from one direction back across the flat profile and up on the other edge.  Most Dark Siders discount the cornering and control issues as they are straight liners.  And of course they do like the reduced cost over the long run.  There are also a lot of guys that once they have tried the Dark Side they come back to real motorcycle tires.

Having rode a big variety of bike types and performance levels I can say with a lot of convection that the Dark Side is NOT FOR SOHC's!  

Thar be a lot of truth to what he says!

Dude, I think you have hung out at VR.org.

[nobody]

mgab, sorry I thought you were talking CB 750.. I dont use the estart, kick works well in cold weather..

Oh, I was talking about the CB. I didn't realize they were so cold blooded, yet another reason I love it. When winter came my Shadow rarely moved, but unless there was snow on the ground my CB was still rideable. I was very impressed with how the cold doesn't seem to affect it. Maybe that's how most bikes are though, this is only my second bike.

[lone*X]

Dude, I think you have hung out at VR.org.

Been there but not a member.  Spend quite a bit of time on VTXOA.com though.  Been a member there for almost 6 years.

[Raul CB750K1]

I don't see the point of a car tire on a bike, unless you are carrying a sidecar.

Sure thing, bigger contact patch provides more traction than bike tire, but I don't want traction in the straights, I want traction in the bends.

Unless I plan to drag race my bike, then, a car tire is the way to go.


I don't buy the "they last longer" argument. C'mon, if you can't afford to replace your tires every 10.000 miles, maybe a Goldwing is not for you. It is like going to buy a Bentley and asking the seller for the gas mileage...

[MJL]

Lets see this video.

http://www.youtube.com/watch?v=WELyf7ydXdQ

[Inigo Montoya]

it is nothing I can test but watching the vids would lead me to believe it is not as bad as some think. Corner transitions did not seem harsh or tippy. if you look closely at the tire, it flexes and looks to have a contact patch a couple inches wide which is easily what the average cycle tire has, maybe more. Now granted these are cruisers and with their greater weight, the tire will flex more and so maybe that helps. As I have heard nothing about a rash of motorcycle fatalities resulting from the use of car tires(look at how news likes to spout if a person did NOT have a seatbelt or helmet), maybe they do work well, on some bikes anyways.
like I said, might be worth testing but would be best done by a pro on a track.

[lone*X]

Be careful people, this subject can get as bad as an oil thread!