Car Tire as Rear Bike Tire - WHATDOYOUTHINK?

[wellston]

Damn. It's past time for two new Continental 4000s for my Bianchi Nirone 7. I never considered that I could get car tires for less. This is awesome!

[GRLambert]

Car tires on a motorcycle are sheer lunacy. I also agree with the comment about lawsuit liability... an opposing lawyer would hang you out to dry.

[NI5L]

Well lets see,....trained engineers with specific experience in motorcycle dynamics and tire construction, versus,....a bunch of $$$$ focused unknowing everyday joes,....making decisions about handling, ride quality, safety focus and especially traction in a much wider application realm than simple car dynamics. Not to mention that mistakes made on motorcycles are highly likely to kill you or permanently disfigure you. Hmm,...doesn't make me think very hard who has the brains in this comparison.

No loss in handling or traction? C'MON,...the guys saying that probably never lean their bike much more than 15 degrees from vertical at speeds a Geo Metro could outdo on four space saver spares. Motorcycle tires are designed to actually INCREASE the size of the contact patch when leaned over from vertical to about 3/4 of the lean angle capability of the tire. A car tire, when leaned over (not rolled over as car tires do when cornering, the carcass deforms laterally to maintain the contact patch) IMMEDIATELY and CONTINUALLY DECREASES the contact patch. Anyone with common sense can see that by simply comparing the tire profiles and the way a cycle leans into a turn versus a car relying on lateral acceleration to deform the tire.

Most cycles, in the sizes we commonly ride, 750cc and above, actually produce higher contact patch loads per square inch than do tires on most cars. That is one of many reasons cycle tires wear out faster. That, and the focus of cycle tires on traction over mileage, which also accounts for higher wear rates.

I'd say most every "car tire on a motorcycle" rider never has found what a cycle is capable of in turns, and also never learned/trained himself to be able to use even 1/2 of what a cycle can do. So sure, to them, "no loss of handling or traction" is a viable statement. That's equivalent to someone from Kabul Afghanistan saying "its a great place to live" if that person has only lived in Kabul.

Let them make their claims, but I pass them off as misguided fools riding themselves to their eventual demise.

Well put. Nature has a way of weeding out the stupid ones.....

[MOTORRADMIKE]

If you are after longevity, train tires are the best.
Tested for millions of miles by Canadian National Railway, these are guaranteed to go the farthest, with the least amount of fuel, and never go flat.
There is a slight rust problem, but if it bothers you, oil them.

[pffog]

If you are after longevity, train tires are the best.
Tested for millions of miles by Canadian National Railway, these are guaranteed to go the farthest, with the least amount of fuel, and never go flat.
There is a slight rust problem, but if it bothers you, oil them.

I hear they make you corner like it is on rails too

[Polarbear]

Whatever end results occur, those that think outside the box are "leaders". May have shorter lives, but still leaders in my book. I don't have to follow the leader, but those with risk and thoughts of change are still the cutting edge folks that get r done! I try to read and absorb ideas I hear from all sources, reason'em out and discard most of it. I think we all have this in us, just some more willing to speak it outloud and share. The car/mc tires are a phenom that should get more looksee, because when I buy a 20000$M/C, it doesn't mean I have to go poor, buying parts for it. That topic is dead, you bought a expensive bike and now odd tires? No, I got rich saving my money, not just blowing it away on BMW,etc and all the frills that come with it. I am very unreasonable when it comes to prices of parts, tires, oil and the like and we are gouged every day(me too), buying like sheep, no questions asked! I'm no sheep and when a guy brings up car tires on a bike idea, for dollars saved or whatever, we should listen more and JUST PERHAPS, those with knowledge can build a good "NAmerican" Tire for bikes and maybe even a crossover CAR tire that works really well? Outside the box thinkers are the ones. We can Hope. Randy

[SteveAikens]

I've been watching this discussion. Some of you have some pretty harsh comments toward those that are considering running a car tire on their bike.

It's pretty clear to me that most of you have no clue to something like this. I can tell you from experience that running a car tire on the rear of my 1973 Honda CB 750 for 3 years and 18,000 miles was not only safe - it was very comfortable and handled well enough for me to ride with anything out there in the mountains of Colorado, when I lived in Colorado Springs. I had a rim laced to mount it and it worked great.

Further, I can't even begin to count the number of FJR, ST and Wing riders that are running them for Iron Butt Rally and other Rally rides. I also know someone that is now running a car tire on a new GTL, that is currently riding in the MERA 10N10 rally and doing great.

I am not aware of a single failure or issue created that is attributable to a rider running a car tire on the rear of their scooter.

My suggestion is, unless you've actually tried it - or have FACTUAL data that it's unsafe, not speculation - talk to someone that has or is running a car tire on their bike before being so judgmental.

Sorry for the photo quality - it's a scan of a 38 year old Poloroid.

NOTE REAR CAR TIRE. I'm posting this photo full size so you can see the tire.

[greenwald]

Yeah - and as long as you never have a house fire, one presumes pennies are a safe substitute for fuses.

Flawed logic - cheap vs. safe.

Darwin.

[SteveAikens]

Wasn't a matter of cheap Kevin. It was a matter of tire life. I was changing rear tires on that bike 3 to one on the front. The car tire solved that for me completely. Once laced on, that was the last rear tire I bought for the bike.

Again - if you haven't actually tried it - regardless of your theoretical analysis - you can't comment on it's performance or safety with any authority.

Hope you all have a great day.

Personally, I'm off to Amarillo for a ride to a Waffle House in memory of friend Curt Gran - on my RT - with a motorcycle tire on the rear....

[kantuckid]

I used to road race a 91 Talon TSi AWD. I used Bridgestone RE71 tires. I would get about 8k on a set. Mind you, all four wheels got power. Most of my friends with power to one axle got just less than half that. Mileage sucked, but they were were the most sticky, treaded tires I have ever had on a car. They used to run me about $1k a set. Running them around the track used to really kill the mileage......

I do not think there is a motorcycle tire conspiracy. I would say the higher price on motorcycle tires has more to do with supply and demand. There are many times more car tires bought each year than bike tires. That makes this a more specialized type of manufacturing, which usually carries higher prices in any item type. I would also think that manufacturers keep bike tires on the sticky side for our safety. I know I have no desire to put a $30, rock hard doughnut on my bike. I never much enjoyed lack of traction on two wheels, less I be on dirt with the appropriate bike....

IMO,the whole tire pricing structure is smoke & mirrors . Not many consumables that get the price spread from true wholesale to retail that tires get . Not quite the borderline criminal pricing of retail jewelry but it has its issues.

[greenwald]

Wasn't a matter of cheap Kevin. It was a matter of tire life. I was changing rear tires on that bike 3 to one on the front. The car tire solved that for me completely. Once laced on, that was the last rear tire I bought for the bike.

Again - if you haven't actually tried it - regardless of your theoretical analysis - you can't comment on it's performance or safety with any authority.

Hope you all have a great day.

Personally, I'm off to Amarillo for a ride to a Waffle House in memory of friend Curt Gran - on my RT - with a motorcycle tire on the rear....

LOVE the Waffle House!
Enjoy your ride.

[RINTY]

Well, we've finally got a new topic to chew on.

Meanwhile, the Word Association thread approaches 40,000 replies and 1.5 million views.

[R1200RClassic]

strangest thing is I had a dream last night (or nightmare depending on how you view it) that I came home and saw my R1200R with a car tire on the rear... how weird is that?

[BlackDenis]

A valkyrie showed up with a car tire.

There is quite a discussion on the BurgmanUSA forum about this and some there are real advocates of the darkside. I asked the Suzuki mechanic at the shop where I had bought a Burgman 650 about this and he said that so many Valkyrie owners had done this - and subsequently destroyed their rear bearings - that it was hard to find Valkyrie bearings.

There is video out there http://www.youtube.com/watch?v=QwSSXHanpv0 that shows how the car tire loads the rear bearings unevenly.

[yonderbob]

This has been going on since the invention of the motorcycle. Unfortunately, no one keeps statistics on car tire failures when mounted on motorcycles. Obviously it works for some folks and they are willing to accept the risks (which they see as non-existent). Not for me.

bob