car tire size for Vstrom ??? (Pros and cons of car tire on a bike)

Works on my Victory Vision.

I'm using a 195/55R16 Dunlop Winter Sport run flat snow tire. Tire pressure 38 psi.

I did an 11,000 mile trip in 2012 that included a stop in Key West, FL and Prudhoe Bay, AK. I had rain everyday from Key West to the Alaska border.
I had interstate, two lane mountain roads and 100's of miles of gravel/mud.

Based on the results from that trip I installed another Winter Sport.

No, by definition that's the very person that caused the idiot's warning label to be required.

I am actually not a darksider myself, so I am not claiming to be an innovator or creative talent or any such thing. I do think experimeting can be useful. I like the idea that there are people out there who try alternatives to the known/approved solutions. I agree that many attempts end in failure. I also believe that naysayers are sometimes overly cautious hand-wringers. Just because something wasn't specifically designed or approved for a given application doesn't automatically mean it isn't safe for that application, it just means the manufacturer didn't intend or test it for that.

It appears that the use of car tires on bikes has been occurring for a while now. Does anybody have any evidence of a catastrophic (or otherwise) failure of a car tire on a bike causing damage to a rider, or bystander? I guess I haven't specifically seen any evidence (if there is some, please hook a brother up), and there are plenty of people who seem to have had success with the car tires. To me, this means that the naysayers sound like overly cautious hand wringers in this case.

Actually, those are called "attorneys", or sometimes "lawyers" or perhaps "barristers", in conjunction with crazy rules and laws requiring manufacturers to try to protect stupid people from themselves. Warning labels tend to occur when people don't understand what they're doing has an element of risk but they proceed anyway, and then blame someone else for it i.e. "nobody told me it was dumb to stick my foot under a running lawnmower."

To me, that is much different than the deliberate experiment crowd who generally, at least, tend to consider the risks of what they're doing. These people, at least occasionally, also take responsibility for what occurs as a result of the experimenting.

Ya know, it would be one thing if the car tire nuts said, "yeah, the handling sucks. But they last forever and I don't really throw the bike around that much anyway." That would be a legitimate argument.

Instead they go on and on about the awesome! handling and the ability to beat sport bikes on their VStroms! Which makes them sound insane.

Note a couple of things from these darkside threads: first, nobody advises putting a car tyre on the front of a moto. Not sure what this means but I suspect that it has been tried and found wanting. Which suggests to me that there is a big difference between a ct on the front of a moto and one on the back.

Second: any twin-track vehicle with suspension will tend to roll; some car suspension systems create tyre camber change with wheel travel and/or roll; suspension geometry can address this but may not. Many cars exhibit a lot of roll when cornering. Many car tyres undergo during cornering wide changes in tyre angle to the road surface.

From this it is clear that a car tyre does not have to run perpendicular to the road surface at all times in order to offer satisfactory grip and to run safely. In turn, it must be possible to get grip when leant over out of a tyre that looks as though it should only work if perpendicular to the road. If the amount of grip satisfies the user, why deride their tyre choice when it offers a significant wear advantage?

For a car, a "lot of roll" might be 15º of lean. For a bike, it's a lot more than that. In addition, in a car, the lean is to the outside of the corner, so the transverse forces on the tire when leaned go in the opposite direction than with a bike. In further addition, the leaning of the car is a *consequence* of cornering, not a *cause* of it. Part of how a bike turns when leaning is that the effective radius of the tire goes down when cornering, and back up when the bike is picked back up to vertical. This has effects in bike chassis attitude, rake and trail, steering characteristics, effects of trail braking, and so on.

I advise against messing around with all of that, for the same reason I advise against buying cheap-ass motorcycle tires for one's bike -- your tires are what connects you to the rest of the universe, and if that connection fails, you will find yourself re-connecting to the rest of the universe in ways that are uncomfortable at best, lethal at worst. Sure, you might get away with such practices for a long time, maybe even forever. But keeping my safety margin high is worth more to me than the savings from a longer lasting tire. (This is also why I always wear a helmet, etc.) Others may (indeed apparently do) value themselves less highly.

PhilB

So you just have it in your head that the "handling" must suck and is just terrible the entire time you are riding the bike? Would that make you feel better if we did?

The truth is the handling isn't as bad as one would think with a "flat" profile car tire. Let's face it, if the handling was that bad and so terrible 100% of the time you rode the bike, there wouldn't be that many people doing it and continuing to do it. I don't care how cheap, frugal, or nuts a person is, if the CT was that bad to run, people wouldn't run them and wouldn't continue to put new CT's on after they wore through the first one. So what does that mean? It means that it actually must work somewhat decent for people to keep running them. Is there a trade off, sure. There's always a trade off on every single motorcycle tire out there. Sport bike guys would run the stickiest track tires they could 100% of the time or DS guys would run the knobbiest tires they could find, but unless you like buying & changing tires all the time, many people have to compromise and find a tire that lasts a bit longer and maybe gives up some of the characteristics they are looking for on their particular bike setup. So for CT's its the same. You obviously gain a huge amount of tire longevity & traction which are the 2 big points for most guys. In some cases as Randyo, he gets improved traction, stability, and tire flexibility by running winter tires on his setup. Depending on the CT size needed, some guys can find CT for rather cheap (IE Goldwing riders). The trade off just like MT tires is how that tire works in the type of environments you generally ride. Most of the guys looking at CT are probably long distance riders, so tire longevity is their top priority.

So back to the handling. There's so much that changes from one setup to the next that its hard to lump them all together, but generally speaking, yes the input of a bike between the same bike running a CT or a MT is different, but don't immediately think its bad. It's just different muscle memory that you develop for riding with a CT and once you become used to to your setup, your tire, etc, it becomes totally naturally riding with a CT. I'm sure like most people who first tried this, I was being overly cautious early on, but then as time went on and my confidence grew in the setup, I started to push it more and more and really came away impressed that a profile like a CT could really work that well on a bike. After I gained some confidence, then I started going out trying to push the limits to see if I could cause it to give up and it never happened.

Once you get used to the different feedback the CT provides on your bike, normal everyday riding is essentially the same. This is why guys that like it keep coming back to CT's. It doesn't change their overall riding experience as much as the naysayers want to believe it really does. Riding down an interstate or highway with easy sweepers really doesn't feel that different. It's amazingly stable and so easy to ride. Traction is phenomenal, both in the dry and the wet. One of the first places I really became comfortable with my setup was just riding down the road or highway.

So where do you feel the difference the most in a CT setup? Again, this varies from bike to bike and CT to CT, but overall I would say slow parking lot maneuvers is one place that takes a little more getting used to. This would include taking off from say a stop sign and making a 90 degree right turn. That initial input to lean the bike over at slow speeds is a bit more pronounced. Just like learning to ride your particular bike though, once you learn the muscle memory for this action, it becomes a non issue. Every single tire you run on your bike feels slightly different in some form or fashion and its the same with a CT. After a little bit, you become used to and accustomed to how the bike handles and responds to your inputs.

The other place for me that I was initially nervous about was aggressive playing in the mountains. I come from a sport bike back ground and have spent plenty of time at the race track, so I was pretty skeptical that I would be happy here. It didn't take me long though to start really pushing the CT and actually become pretty impressed with it. I found my comfort limit at how far I was able to push a Vstrom with a CT, but it really was about 90-95% of my normal "aggressive envelope", and I don't generally ride that hard all the time. I was able to push a CT a lot more than a truly expected to be able to. Now I don't live in the mountains and my riding doesn't consist of heading to the mountains every single weekend. I occasionally find myself there and I was cool with how the CT handled and how far I could still push my Vstrom and it was great for the long slab ride up there and back when I did go. It was still plenty fast to get myself in trouble and it didn't slow me down from chasing all my buds down.

I tried a CT and did 5k miles on one on my Vstrom 650 and I'm glad I gave it a try, but I've decided at this time to move on. Where did CT's leave something to be desired for me? Off-road riding is where I found my dislike. There's plenty of "traction" when the tire has grip, but I felt the extra weight of the CT was over whelming my rear suspension with hard hits or washboard surfaces and when I hit "obstacles" that contacted just part of the tire, they tend to deflect you quite abruptly in the opposite direction. Obviously, upgraded rear suspension could have helped here a bunch as stock Vstrom suspension is vary lacking to begin with. If you got the rear tire dancing around, it could get a bit interesting, but then again, the same thing can happen with normal street tires. I actually think a "softer" winter tire with larger lugs would have done much better off road and I would have been much more impressed off road with it. I was running a pretty sporty CT, so I didn't expect much off road from it, but every where else on the road, it exceeded my expectations. Now don't get me wrong, I think a CT would make an awesome Dalton Highway Tire or Trans-Lab tire, but my off road riding was more "technical" than that and that's where I found my dislike. And most CT guys aren't venturing off road in their setups either, so its a non issue for them.

So now I'm trying a TKC front tire and Heidenau K60 rear tire. The TKC is a very knobby front tire and although its got its own street limits, its actually a fairly good handling tire on the street. I've enjoyed knobby tires before on my strom, but the rear TKC's wear out extremely fast. Now I'm going to try the K60 on the rear and see if I can get some decent mileage, enjoy it off road, and still handle well for the rest of my riding. The K60 has some mighty big side lugs its self so I'm sure it will give up some handling in the mountains, but again this wasn't my main focus; Off road playing is my focus right and so I'm trying these tires now.

This should end the discussion. If it works for the batcycle, then it must be ok.

TL;DR, but yes, I've ridden on squared-off motorcycle tires before. And they suck. A car tire, which is even more squared off, would suck worse.

Sometimes I tell my wife, "Honey, you can take all the words in the English language, and put them in any order you wish. When you're done, you'll still be wrong." Kinda like your post above.

I have seen the claim of better traction made a few times in this thread. Just asking why CT users claim there is better traction? Just the user's feeling/personal experience? A comparison of rubber compounds between CT and MT? Actual testing?

Is there a specific condition where the CT traction is better/worse than comparable MT traction?

Only through turns. So don't do that.


It's interesting that some of those espousing car tires on motorcycles identify themselves as part of a group, calling themselves 'Darksiders' as if they were cultural rebels of some sort, as opposed to just admitting being cheap or low on funds.

Good grief. Some people have replaced "riding" a motorcycle with sitting inside, in a chair, "posting about riding a motorcycle".

Turn off the computer, there's a button, and go ride. It's more fun than getting mentally stressed about someone else's moto tire who you'll never meet and might live on a far far away continent from you.

I have to admit to never riding on a car tire, but I don't give two hoots. You happy, me happy. Just get out and ride, even if it's on a hand woven tire braided from industrial grade hemp grown in your garage.

But then I've never passed Rossi on a Vstrom (I've never even been on a Vstrom) like a loooooot of posters here.

If you are happy with your tire then I'm tickled pink and find no reason to ridicule you or pontificate on how I'm such-a-better/faster rider than you. From behind my keyboard of course where all keyboard pilots are MotoGP capable : )



DO

No irony there!

You know, it's interesting about bringing up squared off MC tires. A lot of MC tires do square off and comparing to how they handle new, they definitely change their "shape" and their beginning handling characteristics do change as the tire profile flattens out. CT profiles don't change as the tire wears so how they feel in the beginning is how they feel when they wear out. Lots of time to get used to that shape. :) You are right that squared off MC tires certainly don't feel the best and they might just handle worse than CT's since you still have that edge to fall over on and the tire doesn't flex like a CT does. :eek1

There's nothing wrong with my long post above other than you'll never agree or see where the CT guys are coming from. You are obviously one of those people that we'll never change your mind regardless of what we say and that's fine. No one in here is trying to tell you you should ride with a CT on your bike. We are just giving our experiences and exactly what I gave. Why you keep insisting on staying in this thread telling everyone in here that they are crazy and must be delusional is beyond me.

No scientific claims, just real world riding and pushing the different tires. When playing around and trying to lock up the rear CT both on dry and wet pavement, it takes significantly more effort to lock up the rear tire in a CT setup. This is especially true if you are straight up and down. There is a much larger foot print and friction area. Also, coming out of a turn in the wet where I know I could spin up a MC tire, the CT tire just sticks. I've pushed the CT well beyond what I would consider sane on a MC and it just sticks. We were actually on the Blue Ridge Pky last year with 2 of us with CT's and 2 guys with normal tires. I was following my buddy and another guy and comparing the "track" the CT was leaving on the wet road compared to the MC tire was pretty amazing to see the CT was leaving a wider footprint, even in the turns. Also the CT a lot of us are running are pretty aggressive and sticky CT's. A lot of 17" tires, that's pretty much all you find. It's not just your avg family car touring tire.

Just some observations from riding on it.

Not only are they using a car tire,they are using under inflated snow car tires in the summer.


I bet they handle like they are on rails


Those car tire companies just do not want the secret to get out about car tires on bikes


IT IS A CONSPIRACY!!!!!!

I think you are reading into the posts more than what they posted or confusing sarcasm and gist. I "think" most darksiders here posted that the CT does give up a small amount of handling and I {and others} have repeatedly stated that we would NOT recommend a CT out back on a Gixxer.

The statements that I think you are getting confused about are not really statements saying that we could outrun Rossi on our CT shod DL650. We were simply kidding around with the fact that even though we are running a CT that admitedly does give up some amount of handling {notice I said handling, not traction} on DL650 we could still give a bunch of so-called riders fits even on their sportbikes. If you don't think it's possible for an experienced rider on a DL650 with a CT on the rear to show it's ass to a squidlet on a sportbike,,,,,,, well, you don't ride much. There are alot of so-called riders that think they are god's gift to twisties that in reality, are slow as hell. I think we just might have a bunch of those so-called riders in this very forum and they are not the ones running a CT out back is ya catch my drift.

Again, for the umptenth dozen time,,,,, a CT isn't without it's compromises. It does handle "differently" but not terrible. Put a ME880 on the back or worse, on the front and tell me how wonderfull that MT is. It's just that it's compromises are no where near as bad as those that are without any experience in the issue what-so-ever think. We would not put them on a Gixxer and rail Deal's Gap but my god,,,,, who buys a DL650 just to play Rick Racer???? :huh

Common sense folks,,,, go get some.

So maybe you should point out the irony for me.

I've been riding since I was 11 years old and I've never felt the need or desire to tell anyone what to ride or what tires to use.

Ride what makes you happy. Use tires that make you happy.

Your choices aren't my business when it comes to your wife, car, moto, moto tires, what you have for dinner or the tattoo on your forehead.

Some people have typed thousands of words here arguing something that has no effect on their life. About something they've never done. That's just goofy and smacks of tooo much time on the interwebs.

I ride every day, I go months without even seeing this forum. Take from it what you want but that's all there is to it. That's why there are so many flavors of motorcycles for sale, everbody's different.

DO

Great post and it mirrors my experince with the CT exactly. Shame that the nervous nannys on here will either not read it, pick it apart based on nothing but ridicule or just ignore it because it doesn't agree with their line of though,,,,, you know,,,,, cause they are the "fast ones", the one's "with all the experience" or the ones that know better because they are the engineers or smart ones.

I just don't get why it bugs them so much? Geeze,,,, we are doing it, we are not saying you should and we are not making fun of you if you don't so no skin off your nervous, worried, too skeered to do anything asses.

This is hilarious. This guy buys a modern motorcycle, puts a _car_ tire on it, and then says: