• Can't post after logging to the forum for the first time... Try Again - If you can't post in the forum, sign out of both the membership site and the forum and log in again. Make sure your COG membership is active and your browser allow cookies. If you still can't post, contact the COG IT guy at IT@Concours.org.
  • IF YOU GET 404 ERROR: This may be due to using a link in a post from prior to the web migration. Content was brought over from the old forum as is, but the links may be in error. If the link contains "cog-online.org" it is an old link and will not work.

Car tires on motorcycles

Ron,
Welcome.  Interesting place to make an interesting first post. LOL  Glad to see you're a COG member.  Again, welcome.

Doug,
Your rear rim is the same as all early Connie rears.  It's the FRONT that's wider on the post 93 models.  However, while most of us are doing 17" conversions on our Connies looking for more tire options, there is a 15" conversion that can be done too.  I think this is your rim for that. a ZL1000 Elliminator. It's wider than a Connie rim, but not sure by how much.  I think it's pushin' the limits of space though IIRC.
http://tinyurl.com/6374e9t

This is a bolt-on if I remember correctly.  Dan about had me talked into it a couple of years ago and I'd still like to try it out for curiosity's sake.  Just sayin'.

 
  No problem Doug,

I have developed a thick and righteous skin on the subject. Hee hee.
As a COG member you can visit the Concourier Archive for the article.
Go to member area in the left column of the COG home page ....assuming you are logged in.
Look for library click, , Concourier articles, click, and Summer 2008 (Vol 20, No. 2) click
Pay atention to the password prompt directions before attempting to download.
My current 15" tire and so far favorite CT is the Federal tire and has no clearance problems but is tight.

doug said:
So DANO,
I read about the Valkirie and the 15" rim conversion but didn't find the CT size-that-fits for the 16 inch 2006 rim (wider I believe than earlier C10s) I do 90% vertical slab riding (.001 horiz riding  :p ) and I am interested in getting the milage from a ct. I already am accustomed to the transition with a quickly becoming flat rear tire. You can pm or email me with the info since it is sooo controversial and deadly.  :-\ ... dougnkitty@juno.com

Ron, I assume the 92 Connie is NOT on a CT and I'm guessing you ride something other than a Connie WITH the CT?..
Click to expand...
 
Car tires on motorcycles? I'm not sure if it is safe. I think it is dangerous to use car tires to motorcycles since the tires for cars are bigger than a normal motorcycle tire. Safety should still be the priority in driving. If this is the practice of other people, using car tire to their motorcycle, then I think Goodyear Tires should make tires for motorcycle. Goodyear is one of the best car tires makers in auto industry. I believe the main reason behind the company's unfailing success is innovation. Right now, a new innovation was presented to the public by Goodyear. According to a Monday press release, Goodyear is creating a new tire that will not only monitor its own pressure, however will re-inflate the tires as needed for maximum safety and performance.The business has not mentioned a time frame when the technology will be available to consumers.The business has dubbed the new system Air Maintenance Technology, or AMT. Article source: Goodyear develops a tire that inflates itself.
 
"the Department of Energy’s Office of Vehicle Technology has awarded Goodyear a $1.5 million research grant"

Do I get a free one for partly funding the research?  :eek:
 
I only got about 20,000 miles on the car tire I had on my VTX.  But at $129 for a rear for that many miles, that was a pretty good deal, IMO, as I was getting 8k on the MC tire.

And it stuck to the road in the twisties like glue.
 
If you are comfortable using a car tire, and ok with the risk then by all means go for it.  After all, safe motorcycling is all about reducing your risk to whatever level is personally acceptable to you.  I have  no problems if people want to go to the Darkside as long as they are aware of the risks/rewards.

What I DO have a problem with, is all the people insisting to people that "oh it's perfectly safe, there is no risk with it" to newcomers etc.  I recently had a conversation with a guy who was going to do it cause multiple people  (on another forum) told him it was 100% safe to do. When I pointed out the risk factors to him he was shocked as he had never thought about it...He still decided to do it since it was acceptable to HIM ..(now that he knows all sides I wish him lots of happy miles)

the FACTS are as follows

1) Car tire sidewalls are NOT intentionally designed to take the lateral stresses that a Motorcycle induces when turning
2) Motorcycles turn by leaning, car tires cannot lean as well as Motorcycle tires,  so even if you don't notice it, you ARE reducing your effective turning ability overall.


That being said there are many people doing it without problems, and for them they have accepted the risk and that's fine, but keep the facts in mind when you make your decision.

I personally will never, ever put a car tire on a motorcycle....but if you are comfortable with it then I wish you many happy miles!
 
I too was skeptical of a car tire on the rear of a motorcycle.  I have worked with a major tire importer for the last 20 years and felt I knew a great deal about tires.  About 2 weeks ago I rode behind danodemotoman through some pretty fast twisties.  Dan's rear tire is a car tire.  I know it shouldn't have worked because of structural differences in motorcycle and car tires but... G** D***, that Dan can ride. I could barely keep up with him.  35,000 mile and his car tire and he was still still gaining distance. 

Ask an aeronautical engineer and they will tell you that on paper bumble bees can't fly. The surface area of their wings isn't great enough create sufficient lift. I have been stung by both bumble bees and Dan with his car tire.

I'm not advocating everyone switch to car tires, I'm just saying perhaps the loads that a 3500 lb vehicle puts on a car tire is different than the load of a 650 lb bike.  Ultimately, it works for him.  Having witnessed him ride that punk I can only shake my head in amazement.  The fact that we may not understand why it works doesn't negate that fact that it's working and has done so for 35,000 miles.
 
The basic principles of bumblebee flight, and insect flight generally, have been pretty well understood for many years. Somehow, though, the idea that bees "violate aerodynamic theory" got embedded in folklore.

According to an account at www.iop.org/Physics/News/0012i.1, the story was initially circulated in German technical universities in the 1930s. Supposedly during dinner a biologist asked an aerodynamics expert about insect flight. The aerodynamicist did a few calculations and found that, according to the accepted theory of the day, bumblebees didn't generate enough lift to fly. The biologist, delighted to have a chance to show up those arrogant SOBs in the hard sciences, promptly spread the story far and wide.

Once he sobered up, however, the aerodynamicist surely realized what the problem was--a faulty analogy between bees and conventional fixed-wing aircraft. Bees' wings are small relative to their bodies. If an airplane were built the same way, it'd never get off the ground. But bees aren't like airplanes, they're like helicopters. Their wings work on the same principle as helicopter blades--to be precise, "reverse-pitch semirotary helicopter blades," to quote one authority. A moving airfoil, whether it's a helicopter blade or a bee wing, generates a lot more lift than a stationary one.

The real challenge with bees wasn't figuring out the aerodynamics but the mechanics: specifically, how bees can move their wings so fast--roughly 200 beats per second, which is 10 or 20 times the firing rate of the nervous system. The trick apparently is that the bee's wing muscles (thorax muscles, actually) don't expand and contract so much as vibrate, like a rubber band. A nerve impulse comes along and twangs the muscle, much as you might pluck a guitar string, and it vibrates the wing up and down a few times until the next impulse comes along.
 
An interesting story, Zorlac, thank you for clearing that one up. Now, how about the one where some engineers at MIT proved on paper a Harley engine could not run?


And... No, I am not taking a swipe at Harley, I read that somewhere...
 
WillyP said:
An interesting story, Zorlac, thank you for clearing that one up. Now, how about the one where some engineers at MIT proved on paper a Harley engine could not run?


And... No, I am not taking a swipe at Harley, I read that somewhere...
Click to expand...
I thought 108 years of production already proved that.  :beerchug:


Now you;ve read it here... it must be true.
 
Mad River Marc said:
the FACTS are as follows

1) Car tire sidewalls are NOT intentionally designed to take the lateral stresses that a Motorcycle induces when turning
2) Motorcycles turn by leaning, car tires cannot lean as well as Motorcycle tires,  so even if you don't notice it, you ARE reducing your effective turning ability overall.
Click to expand...

Marc, I believe number 1 above might not be an accurate statement.  Car tires are designed for lateral stresses.  Both they and motocycles create them.  the question in my mind is which creates more.  Cars lateral stresses are accompanied by a 3500 pound vehicle.  Motorcycles at 600 to 800 pounds.  I'm not so sure which creates more.  Food for thought.....
 
It's not the amount of stress placed, it's the KIND of stress that has me concerned.

Cars usually don't have the tire "Leaning" over to the angles Motorcycles do, all their lean is accomplished in a much lower angular range.  This changes the nature of the stresses on the sidewall/bead

Does the weight difference make up for it?  Maybe, but until someone does a scientific study to prove it's safe (Not the "I can't keep up with Dan" or "there are tons of people doing it without problems" type of study) then I will err on the side of caution and advise people of the risks.

Again, I am not saying don't do it,  if you are ok with the risk then by all means darkside away,  but don't sit there and insist to everyone that it's no risk..
 
I hear what you're saying.  I agree with your basic premise that there are risks introduced even if they can't factually be quantified.  unfortunately, there are folks on both side of the debate who make statements as fact without data/information to validate them. 

There are a number of things I've learned about the CT debate over the few years I've researched it.  I did try running one after some research of my own.  It didn't work for me, but I'm the type of tinker and try things.  My comments to folks are usually that they should research and determine for themselves.
 
NEWSFLASH!!!

I spent Monday catching 2-3' sharks on freshwater, rattlin', deep-divin'crankbaits on every cast in colors that sharks don't normaly encounter. 

Who knew?  :)


Philosophical Pragmatism has been the American way for decades.  "If the shoe fits,wear it" "If it fits, it ships" The concept is basically, "if it works, go for it" or more simply, "use what gets the desired results".  Theory and practice are not two separate things, but work hand in hand.  Sometimes theory has to change because practice calls theory into question.  Too often theory prevents accomplishment because it limits exploration.
 
Rev Ryder said:
NEWSFLASH!!!

Too often theory prevents accomplishment because it limits exploration.
Click to expand...

SOUNDS JUST LIKE MY WIFE! I try some exploring to accomplish and, well, she limits me........ :-[
 
Scary stuff! :motonoises:
Uber lateral stress there!

img_1334.jpg
 
LOL, that thing is leaning, what like 7, maybe10 degrees at the most, and it is scraping? It should not have car tires, it needs truck tires!
 
danodemotoman said:
  OMG  :-\
Look at that contact patch!!!
Click to expand...


Yeah, but a little exercise and a low carb diet and it'll get better.  THat's what my wife tells me about mine.  :D

Definitely not a sport tourer, but a bike tire wouldn't get him any more lean.
 
Mad River Marc said:
the FACTS are as follows

1) Car tire sidewalls are NOT intentionally designed to take the lateral stresses that a Motorcycle induces when turning
2) Motorcycles turn by leaning, car tires cannot lean as well as Motorcycle tires,  so even if you don't notice it, you ARE reducing your effective turning ability overall.

I personally will never, ever put a car tire on a motorcycle....but if you are comfortable with it then I wish you many happy miles!
Click to expand...

Hi Marc,
I've followed this thread with much interest.  My best buddy on a VTX 1800 went to the Darkside and
reports essentially exactly what Dan reports (with fervor).  I'm not sure why, but you seem like this actually makes you mad, like your upset that someone is messing with some natural law.
At any rate, I have to dispute your first point above:  My car with a built in G meter will pull over
one G in a corner, that's lateral stress. How can you say that a car tire is not designed for lateral stress?
I say the sidewalls on a CT are designed exactly for high lateral stress (not for touching the road surface though).  Which brings me to: As Dan has said and my buddy confirms (to me), before the
CT can get to the sidewall the bike would hardpoint. The wear pattern shows that the CT never comes close to "rolling onto the sidewall". Again as Dan said, the little mold nibs are still there, and he's
feels the bike is turning harder/better than ever.  The difference is that it takes more input to get
the stiffer sidewall (damn pesky sidewalls) to flex.
Question for you:  Why do bike tires only last 5 or 6 or 7K miles?
Interesting topic.
Regards,
Paul in North Jersey (my first post)  ;D
That just sounds silly.
The evidence supports
 
Question for you:  Why do bike tires only last 5 or 6 or 7K miles?
Click to expand...
Rumor has it the softer the rubber the greater the traction.
The softer the rubber the less miles you get on the tread.
Rumor provided by a Camaro-driving buddy re drag racing tires circa 1975.
If only I remembered as much of what I learned in my classes...
 
The contact patch is much larger on the car tire.  :-\  At all attitudes and conditions. BTDT  :))
The CT tread compound is reported and measured with a durometer to be SOFTER than a MC tire.
So my contact patch on the seat tells me the CT tire lasts longer due to the larger contact patch even with a softer compound.
Can 50 billion car tires be wrong?
It is amusing when a poster thinks that guarantees and engineered assessments using a car tire are required yet that rider does not demand the same for a MC tire not recommended by the bike mfg. So use whatever criteria for your choice as you expect of others choice.
Have you fondled your tread today?  :88:
 
Of course car tires are only the "gateway" into more serious forms of insanity.  The examples I've shown are what COULD happen next.
06_018.JPG
 
Unless we crush this movement now there's no telling where this might lead.  THey could start putting pontoons on airplanes and propellers on boats and motors on kites.  We MUST stop the insanity NOW!
 
Rev Ryder said:
Unless we crush this movement now there's no telling where this might lead.  THey could start putting pontoons on airplanes and propellers on boats and motors on kites.  We MUST stop the insanity NOW!
Click to expand...

Relax Francis!
 
2linby said:
Rev Ryder said:
Unless we crush this movement now there's no telling where this might lead.  THey could start putting pontoons on airplanes and propellers on boats and motors on kites.  We MUST stop the insanity NOW!
Click to expand...

Relax Francis!
Click to expand...
Not as long as I gotz wurk to do...
:deadhorse:





;)
 
Wore out a car tire on my VTX 1800... it took me 25,000 miles to do it.  25k miles of peg dragging and daily commuting.  Works great.
 
wally_games said:
Bet you can't do this with a car tire... ...
http://cyclenews.coverleaf.com/cyclenews/20110920/?pg=61&pm=2&u1=friend#pg61
Click to expand...

Uhh...bet 99.99% of riders can't do that on motorcycle tires...just sayin...
 
I've scraped BOTH elbows in a single turn before.  Still got the scars to prove it too.  :))


I have to admit though, it was on motorcycle tires.
 
Zorlac said:
Couldn't stand the uber lateral stress, huh?  :motonoises:
Click to expand...
Yeah, but my tailor was able to fix the jacket... the pants were another matter altogether.  :sign0137:
 
Paul North Jersey said:
Hi Marc,
I've followed this thread with much interest.  My best buddy on a VTX 1800 went to the Darkside and
reports essentially exactly what Dan reports (with fervor).  I'm not sure why, but you seem like this actually makes you mad, like your upset that someone is messing with some natural law.
Click to expand...



I don't have anything against using a car tyre actually.  As long as you are aware of the risks and they are acceptable to you then by all means go for it. After all, safe motorcycling is about reducing your risk to personally tolerable levels.  This is the same reason I am pro helmet but anti helmet law,  as long as you know the risks it's your life and your body and you should be free to do whatever you want with it.

What I DO have a problem with, is when people start asking about Darksiding, and get overwhelmed with responses stating "There is no risk, it's perfectly safe, I've been doing it for blah blah miles" and such,  they portray using a car tire as a 100% safe alternative to a MC tire and say it will handle as well blah blah blah.  THAT is what I have a problem with. 

Bottom line (IMHO) there IS a risk associated with running a Car Tyre on a MC,  what degree of risk is it?  I cannot answer that as I am not an engineer (and I suck at math anyway :) ).  Again I'm not saying DON'T do it,  I'm saying know all the FACTS before you make your decision,  if after knowing all the facts, you decide it's an acceptable risk then I support your right to run a car tyre!

Ps,  The lateral stresses placed on a tire are different in a car then a bike so I stand by my statement that they weren't designed for it. (Car's pull sideways bikes lean etc)

 
Car tires on choppers were the cool set up in the 70's, but they didnt lean much over anyways.  Too scary a set up for me on a leaning motorcycle..
 
I'll accept millions of anecdotal miles of testimony as proof, thanks.  I believe I'm a reasonable person in this regard. 
 
I wouldn't think of doing this if I hadn't ridden a Goldwing with a ct on it yesterday. This guy had a 160k miles on his GW and was getting 30k miles out of car tires. He rides 2 up pulling a trailer. Not having a lot of seat time on a GW it semed ok to me on the highway and in the turn. If he was changing out motorcycle tires every 3,000 miles he would have put 53 tires on in that time. Is there any brave soul out there who has tryed a ct on the C-14 and willing to report his findings.
 
On a sidecar rigged bike maybe , bottom line is....do what you want . But it shouldn't be promoted as a great idea because it's just not .
 
"Cocaine is for horses,
and not for men.
They say it will kill me,
but they won't say when."

Not sure why that came to mind when I hear stuff like this...
 
Just consider the noticeable difference between a 190/50 rear tire and a 190/55 on a C14. Increasing the crown diameter makes the bike "fall in" quicker, and with less effort.

A car tire is the absolute opposite direction.

I've seen them try to do U-turns at Bike Weeks, its funny as hell. I can get my little Chevy around easier.
 
I only show 4 pages.  But I'm holding out fer eleven.  :)

If I wasn't such a tightwad I'd have tried this a long time ago just to see what it's like.  Since Dan has logged a lot of miles doing it, there's a remote chance I could do it and not get killed.  I like my odds better than bungee jumping or base jumping or flying a wingsuit or feeding sharks or wrestling aligators or dating young women... all of which seem much more life threatening to me... especially the sharks and young women escapades.  Jim, could you do a feature on young women and the appropriate sfety equipment and preparations required?  :beerchug:
 
Rev Ryder said:
If I wasn't such a tightwad I'd have tried this a long time ago just to see what it's like. 
Click to expand...
When I mount my last Pilot GT & wear it out  :'( if I can find a 16" CT that doesn't rub  ???, I'd like to give it a shot since my Connie primarily does slab duty.

A respected FJR forum member recently tried one on his FJR and went back to a MC tar after posting his impressions on the handling, since he lives in NH and avoids the slab, twisty handling was a big concern for him.
 
WillyP said:
Rev Ryder said:
especially the sharks and young women escapades
Click to expand...

Too dangerous! Stick to da internets and Model Trains!
Click to expand...
Actually, I had a 4 ft. blacktip shark in my lap while in my kayak a mile offshore last month.  I didn't mean for it to be in my lap but it jumped in with me.  For a minute there I'da given just about anything to be home on da internets... fortunately, I came away unscathed again.  Best as I can recall, however, I never was that lucky with young women as to walk away without some serious scathing going on.  :truce:


Hmmm.  Model trains, eh?
 
Unless they are trained sharks as in this feeding session I witnessed at Fiji a couple of months ago!!  Kidding aside there are no trained sharks, just sharks that are so fat they cant seem to find the need to bite anyone!!
 

Attachments

  • PICT0213 2.JPG
    PICT0213 2.JPG
    952.9 KB · Views: 102
  • PICT0143.JPG
    PICT0143.JPG
    1.6 MB · Views: 101
Actually it was the 16 foot Tiger shark that cruised by towards the end of the dive, not so much these bulls!!
(My BMI is 12% :p)
 
You must log in or register to reply here.
Top