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

Discussion in 'The Perfect Line and Other Riding Myths' started by Jimm Dandy, Mar 27, 2012.

  1. Dirty Hippie

    Dirty Hippie Somewhere in a canyon

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    Man, this is far out! Darkside. Lovin it. :clap

    I don't think it would work for me, but it is so cool that someone tried it to find out.
    #41
  2. Jud

    Jud Long timer

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    It's certainly not for everyone but it's not the debil either. No nuns nor kittens have been maimed and the atmosphere hasn't yet caught on fire from those ignorant, cheap ass motorcyclists thinking outside the box.:eek1:1drink:rofl
    #42
  3. Sumo64c

    Sumo64c Been here awhile

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    Kuhmo run flat rear car tire here on my 10' Wing. It has nothing to do with money, it's the run flat capability along with improved weight load. The added stability/ improved wear/ wet weather performance is all bonus. I want the safest tires out there, a run flat rear car tire and motorcycle rear tire on the front give me that for my particular 900lb empty weight ultimate 2 up touring barge.
    When the tire manufactures finally offer run flats for non police motorcycles, I will be the first one in line when they offer them for the Wing, price be damned.
    #43
  4. JDana

    JDana n00b

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    I have ct on yamaha stratoliner and it works really well for two up and pulling trailer. I used the darkside forum for info on what tires work for what bikes etc, mounted myself with harbor freights giant tire irons and only took 20lbs air to seat the bead. I can scratch up rims just as well as the dealer. Now if I could just put one on the klr
    #44
  5. panhead_dan

    panhead_dan motorcycle addict

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    Car tire for klr thread!!!!!
    #45
  6. bogey78

    bogey78 Been here awhile

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    Just out of curiosity, does mpg decrease while running a rear car tire as opposed to a more rounded motorcycle tire? It seems like it would make a small difference at least.
    #46
  7. Mikef5000

    Mikef5000 Long timer

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    Man I'd so like to try this sometime. The reality is it's not for me; I tend use my bikes to their full extent. I've only had the Tenere for a couple weeks, and I've dragged both pegs already. The chicken strips were gone the day after I bought it.

    Maybe someday I'll find someone running Darkside around here that would let me take their bike out for a spin around the block.
    #47
  8. Shercoman

    Shercoman Been here awhile

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    I have had a car tire on the back of my Triumph Rocket III for 14,000 miles.
    It looks like it's good for another 10,000 easy.
    You can tell it's back there if you're on an uneven dirt surface (like my driveway) but you cannot tell at anything above parking lot speeds.
    And I regularly drag the foot peg feelers.
    My next tire will be the same thing.

    So if you've never tried it,you really don't know.

    Should we tell the people on these threads that build dual sports out of street bikes that they should cease and desist because "street bikes are for the street".:lol3
    #48
  9. Jud

    Jud Long timer

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    If you ride alot of dirt and your bike is regularly shod in TKCs, the CT wouldn't be a good choice. Niether would it be a good choice if you regularly run full on sport tires or something like the Pilot Road 2s. But, if you find yourself regularly running tires like the Tourances, 705s or similar,,,,, the CT might well make you happy.

    I ride fairly hard and I thought I would hate it, only mounted it up for a long trip because I didn't want to buy a tire during the trip nor could I carry a spare. Now that it's on and I'm used to it, I can hustle it around fairly quickly. Serious as hell man, it's has at least as much on road traction as a 705/Tourance. Like I said, I would not throw it on a Gixxer and set out for a track day but man, I honestly think it has more in reserve than many adv and touring type tires. Now, if you are running Pilot Powers on your Tenere,,,,, the CT just ain't for you.

    Seriously, throw one on for your next long trip and at least give it a try. Worst case is that you won't like it even for long trips and you are out a few bucks. More likely will be that you can live with it for your long trips and then yank it off for local playing. Then again, you might like it alot and leave it on for all riding. I would if I didn't do so much playing on rarely maintained FS roads because I said before,,,,, the huge width is irritating in rough stuff. Not a complete deal breaker but irritating none the less.
    #49
  10. Jud

    Jud Long timer

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    I think my DL took a small hit in fuel consumption but it's so slight that it's sorta hard to notice for sure. I wouldn't doubt you would lose a smidge of gas mileage due to the extra width but more likely, the extra rotating mass. The CT weighs nearly what the Kenda Big Block and wheel assy did!:eek1

    I will admit that I really noticed that, seems like I lost a good 10hp or so and on the DL,,,, that matters.:cry:rofl

    I also noticed the add unsprung weight, especially when scooting fast on rough dirt roads,,,,, especially washboard. I don't know if most ride hard enough to where they would really notice it or not. The CT has some drawbacks but for me and the way I ride {and I ride fairly hard}, the good outweighs the bad. I honestly think most folks that ride Wings, cruisers and honestly, most that ride Adv type bikes,,, a car tire would be a good choice if not better choice than most bike tires. Like I said, if you are on a sportbike or your adv bike is constantly running TKCs,,,, they ain't for you, don't even try em.
    #50
  11. bandito2

    bandito2 Been here awhile

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    These are some of the very same valid ideas (among many) that I had put forth defending the idea of using a car tire on a Honda Reflex scooter.
    I was the first to do it on the Reflex and now there are several happy Honda Reflex Darkside riders. None of them have gone back to using scooter tires on the rear.

    The banter I often get from gas station gawkers goes something like this:

    gawker: Hey it looks like you got a flat tire there man.

    me: No it isn't flat, it only looks that way. The reason it looks like that is because it's a car tire.

    gawker: Wow! really? (with dubious looks)

    me: Yes really. Works as well if not better than a scooter tire.

    gawker: Isn't that dangerous?

    me: Well no, I don't think it is. But if it is dangerous then your car there is 4 times as dangerous since it has 4 car tires on it. (me grinning, but knowing just how true that statement is.)

    I don't bother to tell them that I am also using a rear tire from a larger scooter (Honda Silverwing FSC600) on the front of my scooter. (so I am what you call a double darksider.) I just don't think it would conform to their view of reality or comprehension. The times I have tried to explain the car tire/double darkside thing, it just goes completely over their head and they stand there blank faced and slack jawed.

    Words of wisdom to the intrepid souls that decide to use a car tire or any other modifications they may make to their bike for that matter:
    Be bold. Experiment. But do so informed as well as you can be and know that consequences for really bad decisions can be dangerous and damaging and ideas that are successful are worth sharing.
    And I also say GO FOR IT!!!
    If it works out, then good for you. It won't matter what anyone else says when you KNOW you are right about your decision. Be quietly satisfied with yourself, speak honestly and modestly of your success and let the naysayers eat crow.

    I can't help but say more about it.
    Braking works fine. No difference in stopping distance that I can tell; Whatever adjustment I may have needed to make has come automatically with experience. The bike handles a little differently than with a standard tire, not better or worse, just different. I have adjusted and it feels natural. Even when one puts on new tires there is adaptation to the difference of feel and handling. We adapt to minor changes quite well thank you.

    For my use, the car tire is taller than the scooter tire. Claims about how it may adversely affect rake angle are bogus. I point out to them "back the rear of your bike up onto a 5/8 inch piece of wood or something and then tell me how much that 'adversely' affected the overall angle. Not so much after all huh?

    Most curved roads have some of that "lean" one gets already built in by virtue of having bank angle appropriate to posted speeds. So the bike angle relative to the road is not as much as one might think. Even scraping hard parts in a well leaned over turn does not use up much of the side of a car tire at all. It stays mainly on the tread of that side of the tire. (see some of the dark side youtube videos to observe this effect.)

    Contact patch of a car tire changes shape when going from vertical to leaned whereas the contact patch shape of a bike tire remains relatively constant through riding angle changes.

    The sidewall on car tires are designed to take tremendous lateral loads imposed on them in turns without any trouble. Bikes rarely make much more than marginal lateral demands on the sidewall. Most of the load to the tire on a bike is vertical or nearly so. They can take it.

    Rubber compound on a bike tire is harder than for car tires. (It is a common misconception to think that bike tire compound is softer.)

    I run pretty close to recommended tire pressure on mine. To each, his own. My car tire load index and speed rating is 77T (908 pounds and speeds up to 118 MPH) So, with the weight of myself dressed to ride (175#) plus the weight of the bike (375#) and add 50# in gear for good measure = 600# Only about half that weight is carried by the rear wheel. With only about 300# on the rear and my scoot strains to hit 85 MPH, there certainly is a huge margin of safety on that rear tire.

    I've got about 18000 miles on one of the car tires I use on my scoots and it shows little wear. $23 for the tire + $7 for shipping = $30. Using standard scooter tires, I would be nearing the need to change to a 4th rear tire. @ about $50 each, scooter tires come to $200 and that is not including the shipping costs nor the cost for mounting tires multiple times. It's a no brainer for me. OK, so I'm cheap. So What? I'm more likely to need to change the rear tire because of its age rather than from wear or punctures, Ditto for the tire I use up front. (well, maybe it will get changed once or twice.)
    #51
  12. 100mpg

    100mpg Self Imposed Exile

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    but...but...they have cookies!
    #52
  13. Jud

    Jud Long timer

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    Sorry for the long post up front. Don't like a wall of text, don't read it. Want to read one person's first hand experience with a CT mounted on the rear of DL650, read on.

    Just gonna update my experience with the car tire on the back of my DL650. It's been on for a good 6K miles now and I just got done with week long, two-up trip down to S. Ga and the panhandle of Florida and down to St George Island. The wife and I fully geared up presents a good 400lb load and we camped the whole week so figure an additional 100lbs for all the gear. The trip was near 1000 miles round trip and ranged from cruising at 90mph to some one-up, unladen playing in the sandy roads of the Apalachicola National Forest. As for how the sand performance goes, the car tire definitely fares better than the front 705 even with the 705 aired down. Suffice to say, I tired rather quickly of the sand but I will say that I think the car tire did better in the sand than the 705 I had on the rear during my Trans Lab trip.

    Now on the other stuff, how'ed it do two up and heavily loaded? It worked great folks, really has. I normally run around 20lbs of pressure but with all the weight of the bike loaded up and with two riders I ended up running around 30psi. Now think about the weight on that tire, I weigh up near 200lbs by the time I'm fully geared up as does my wife. Like I said, I'm betting there was an easy 100lbs of "stuff" on there for our week of camping so you are looking at around a 500lb load on the bike,,,,,,, that's alot folks. And the car tire looks none the worse for wear hardly. I have had the CT on the back for something like 6K miles now {counting this past trip} and I have been hard as hell on it, harder I think than any tire I have tried and it's just starting to show some wear. Not much wear but it's starting the get some alternating block type wear pattern on the side tread blocks {I tend to corner pretty aggressively} but the middle looks perfectly fine. I have been banging the down shifts, have been spinning up the rear on dirt/gravel roads and wheelies every where. Matter of fact, from the looks of the chain,,,,, I think the CT will outlast the chain as I mounted them at roughly the same time.

    To summarize-

    The CT is a bitch to mount but once you learn a trick or two, it's no biggie.

    The CT feels a bit funny at first, feels much better at once you find the right pressure which for me and my bike was around 20psi. Once you get the pressure right and you get some time on it, your confidence will grow and you can treat it as any other rear tire.

    You will notice the extra weight of the CT, mostly in the perceived HP loss from the extra rotating weight and some might notice the extra unsprung weight slightly hurting handling a bit but you have to ride pretty hard to notice that.

    The CT has roughly the same, if not more traction on road,,,,, yes, even cornering on tarmac as my other rear tires have had and I've run Tourances, 705s and a Kenda Big Block.

    The car tire has roughly the same traction in most off road situations as my 705s did and probably more in some such as regular pack gravel roads and sand. I hit a little mud and as you would assume, it did no good in that stuff but neither does any other non-knobby.

    The CT while working fine on most dirt road type riding, doesn't feel too good on really rough, rarely maintained dirt roads. You know, dirt roads that are rutted and rocky from alot of 4X4 traffic and what-not. I think that's simply a by-product of the CT's huge width catching every rock and rut and that pushes and bounces the bike around more than a normal say, 705, TKC or Big Block.

    The CT wears like iron. Seriously folks, I am pretty hard on tires and had I treated a 705 or Tourance to what this CT has been through, I would have had to replace it well before the trip. I have worn Tourances and 705s down past the wear bars in 4K miles or less. I average around 4.5K when riding locally and the most I have ever gotten for a 705 has been around 9K miles on long trip where I babied the heck out of it. It was loaded down heavily but it had no two-up riding, speeds were kept at 80mph or less and like I said, I babied it so I was very easy on and off the throttle and no wheelies to speak of. I think this CT will do an easy 10K, probably at least 15K miles under riding that would have put a 705 or Tourance down to the cords in 4K miles or less! I could see a CT going 20K or more if rode easily, under touring type conditions.

    Please understand that I tend to ride a bit harder both on and off road than most DL650 riders and I will tell you without hesitation that the CT is the best tire compromise I've found yet. I would like the rough off road handling to be a bit better and I would love it if I could get the off road abilities of a Big Block or TKC but that ain't happening and I knew that going in. What I was absolutely stunned with was the on-road traction of the CT. It handles and sticks as well or better on tarmac than any tire I've run on the rear of my DL and like I said, I've run a Tourance, a bunch of 705s and a Kenda Big Block. Honestly, for most people that ride a DL,,,,, a CT would flat out be the best tire to run. I could see ne reason at all not to run one all the time on a full on tourer like a Wing or a cruiser that has limited lean angle.

    As for me,,,,, I think I will look into finding another set of wheels so I can have a set of knobbies mounted on one set for playing on the weekends and the other set with a 705/CT combo for commuting and touring.:1drink
    #53
  14. panhead_dan

    panhead_dan motorcycle addict

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    What about v-strom tires on a car?
    :eek1
    #54
  15. mrphotoman

    mrphotoman Long timer

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    What do all the tire manufacturers know, heck it is only common sense that some internet genius that can not afford a motorcycle tire knows more about tires than huge corporations that have been designing and manufacturing them for years. :rofl
    #55
  16. Mikef5000

    Mikef5000 Long timer

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    Yeah, we heard you last time. Then a bunch of folks chimed in with real world experience. And yet, here you are again.
    #56
  17. Jud

    Jud Long timer

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    Remember,,,,,,,,,,,,,, the peanut gallery?:1drink:lol3
    #57
  18. mrphotoman

    mrphotoman Long timer

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    Lol, nothing funnier than "riders" trying to justify using car tires on bikes and "riders" trying to justify not wearing gear :rofl
    #58
  19. simmersonwheels

    simmersonwheels Asleep at Switch

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    If you were running a car tire and you crashed into a bus stop (for whatever reason), tragically maiming a couple of kiddies waiting for their ride, I wonder what your insurer would say about a car tire on the back when the lawsuits started? My guess is the $100 tire savings might cost you your house and everything in it.
    I also wonder what affect running a car tire 10-12 PSI below recommended inflation has on carcass life. A bike weighs much less tan a car though.
    I could see the advantage if you were running an ironbutt style event.
    For me the joy of a motorbike is all about that initial lean in and turn. I'm always amazed how my bike feels new again when I replace 60% worn decent looking rubber with fresh. Even tire pressure being 2 or 3 PSI low makes the front end feel like lead.
    I believe there are riders who have had good experiences riding on car tires for lots of miles. If you look hard enough you can probably find someone who saves some cash relining their brake pads with recycled linoleum and chewing gum. Just cause it works doesn't make it smart.:evil
    #59
  20. azgsa

    azgsa Apathetic

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    Well wouldn't ya know it, visited the local Ace Hardware store today and low and behold a Darksider was lurking right in front. I was checking it out and the guy walked out and we talked a bit. He has a 155/80-15 mounted on his steed and keeps it aired to 45psi "so it gets a bubble in the middle" meaning a more round profile. :eek1 He said he's had it on for a thousand miles and reports the "cornering ain't as good but in a straight line when you whack it, it grips like a mofo" :lol3 Said there's only one place in town (PHX area) that would mount it, Bob's Used Cycles. If you're familiar with Bob's that would make sense. :huh

    Anyway, I'm really understanding this car tire thing better after my close encounter of the Darksider kind today...

    Pictures are worth a thousand words. :deal

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    #60