MODERATOR NOTE:  I broke this out of badwolf's Shinko Discussion.....just to help keep things a bit more on topic.


In the Savage rim there is a central well or depression that the tire bead slips over into during the mounting process.   Filling this well up with stuff to make it tubeless makes all tires VERY hard to get onto the rim (motorcycle tires too).

Going Darkside on a Savage has other difficulties I won't waste your time with by saying an electric knife, some axle grease and some patience can still fix them.   I deleted all that sort of pertinent info from all the Darkside threads as I don't think it is safe for normal newbies to be trying to do this sort of stuff AT ALL.     <he rubs his left wrist scar as he types this>

My last Darkside rear tire was mounted in the same year Dave went on his first Dragon run, and it has outlived more than several of MM's rear tires (and one of his Savages).   My current Darksider tire is a little older than Dave's Cafe Savage and it is less than half worn out.

It may outlive me ....

If you are a guy that loves to corner hard, and wears out the side tread of your tires, a car tire is NOT for you! But if you look at the old "classic" dresser tires, they looked very close to a car tire. Shinko still makes them in 16".

http://www.shinkotireusa.com/tires/cruiser/classic

Tire sidewalls bend all the time while riding, even when you're straight up, on a old dresser or touring bike that is 95% or more of the time.  Now we have a huge selection of tires to choose from suited for every thinkable task, back in the day it was not so. Car tires can give you long miles on a bike, but if you want to drag your pegs a lot, stick with a tire made for that.

Yep, Oldfeller has a car tire on the rear.....and Yep.....it goes really fast around corners, and Yep......I have worn out a Pirelli Sport Demon, and am on my way to wearing out a Bridgestone Battlax BT-45 and will likely be getting a 3rd tire next year, and Yep.....my tires likely cost 2-3 times what Oldfeller spent on his car tire.  There is very little wear on his car tire....and the tire is barely showing a rounding off of the edges of the tread.

I won't be mounting a car tire on my motorcycle - but it works really well for Oldfeller, corners really well, and lasts a very, very long time. - and it defies what most folks tell you about having car tires on a motorcycle.

I am glad the Shinko 230 has proven to be a very good and long mileage tire that can be purchased at a very affordable price.  I am sure that my "actual mileage may vary" and I would not be able to get the mileage that badwolf did.....as my riding style usually involves taking corners at a brisk pace.  



 

Now, Kris01 asked (again) how car tires can work on a motorcycle because they are not round.

Kris, on your car your front wheels steer the car around corners by flexing the sidewalls,  allowing the car to create cornering forces while keeping the contact patch flat on the ground.  

This is how they are constructed to work.

This is the exact same mechanism that the Darksider tire uses on any sane form of cornering, the thread stays flat and the sidewalls flex to allow this to happen, as it is designed into the tire for it to do.

Now, go up to the Dragon and you do start to go past what this standard car sidewall flex can accommodate and indeed you do indeed tilt the tread on the pavement and it does lift up until about half the tire's tread is up in the air on the most extreme maneuvers....

Disastrous, right ???

Nope, look at how much tread area I've got to engage, even when I have about half of it in the air what remains in road contact is 2-3 times as much contact patch as motorcycle tire ever has, period, ever.

Look at the wear pattern on my tire, it is very similar to what you see on the front of your car.   All wear that you see is within the design parameters of the car tire in front wheel drive / steering uses.

Next, load capacity.   Me and my bike weigh about 600 pounds so each tire carries ~300~ pounds of loading.   A car weights 1-2 tons and each tire is intended and rated to carry at a minimum around a thousand pounds of load.  

I don't think I am going to overstress the Darksider tire no matter what I do.  

So far MM and I have each gone through a Darksider tire, mine died because the TUBE wore out due to a rust spot growing on the rim.   This one has preventions over the rust spots to keep that from happening again.

Kris asked a sensible question (again) because Kris really can't see how it could possibly work.   It does fly in the face of logic, doesn't it?

This Darksider on the 15" rim stuff was "invented" around 1948 or thereabouts when VW beetle tires became cheaply available in the USA and Harley guys realized they would fit their Harley rims.

Fast forward to the last decade or so, and the long distance touring guys on Goldwings were complaining voraciously about having to change their rear tire twice a year at over $150 per tire.    Somebody remembered the VW on the Hurley thing, and the modern Darksider movement was born.  

I paid $32 for my original Nankang tire, my very first Darksider tire.   This last one cost about $59 if memory serves.  The Goldwing guys paid similar money for theirs, instead of paying $150 each for twice a year tires.

Please remember, because the greatest risk to the user is MOUNTING the stupid tire, and that I got bloodied up personally by a bead breaking I don't recommend doing Darkside to anybody.

But personally, if I can pick up a $59 tire at Walmart (yep, go on-line and have it sent to your local Wally @ 0 $$ for shipping charges) then you have to trim off the excess "tubeless" rubber with an electric knife and get you say 10+ years of riding service out of that one tire -- with what I would have to say is EXCELLENT rideability characteristics, then I guess I can afford to take the time to answer Kris's question every year or three.


(reminds me it is time to check my air pressure again, it does)


...... and about that  " if you ride like cornering and dragging the pegs is your only world"  thing .....

There are a lot of folks who ride big sport touring/touring bikes that use car tires on the rear.  One of the big reasons they do on the Goldwing, ST1100 and ST1300 is that the rear tires are very cumbersome to change with all that Tupperware in the way, and some of these fellows go on really long trips.  They can wear out a motorcycle tire in a single trip, and sometimes even 2 of them.....so they mount a car tire and can make the entire trip without changing tires.

The Goldwings and ST bikes have tubeless rims that are pretty wide - so the car tires are easier to mount than they are on the relatively narrow Savage rim....especially when you have to wrestle in a tube.  Oldfeller and MMRanch have run car tires, and MMRanch ran a low pressure and did ruin a tire when it overheated and the chords came apart - when he was running a proper pressure he had no problems, and Oldfeller is trying to wear out his second one.  I don't think the car tire flexes anymore on a bike than they do on a car...on a car they not only squirm - they also roll under a bit, and I believe the tire is built to handle those kind of stresses.

https://www.youtube.com/watch?v=gZKhoFbL7Fo

OK, The darkside can of worms is not only open, but they are crawling all over the floor!!Thanks for the vid link Dave, a lot of footage of the sidewalls flexing. The car tires seem to contour to the road better than I thought.
I would like to see those guys riding and holding that camera under the bike to get that angle. Maybe their wives  are riding upside down holding the camera?

I had a 145/80-15 Goodyear eagle on mine and it served me well for 3 years and 20,000 something miles --- it might have been halve wore out.   Well as long as it had 30+ psi everything was fine.   One year I got the notion to lower it to 20-22 psi and run the Dragon a time or two.   It stuck like glue !  

That was the year we came up behind two big sport bikes flying along.   Well , they speed-up when we cought them and the race  was on !     The one in the rear made the mistake of glancing in his mirror to see if we were gone yet , it made him go wide on the corner he was in.  That was all it took for me to slip past him.   Then the RACE was really on !      I tried to pass his buddy , I'd catch him going into the corners and haft to break to keep from hitting him but that 100 HP coming out of the corners was hard to overcome on a Savage.   He never did go wide enough to pass but we left his buddy way back there somewhere.  
Long story made short is : Don't let anybody tell ya that a car tire on a bike is a handycap.  Like OldFeller already stated - even with half the tire up in the air --- there is still more rubber on the road that bike tires have on their best day.
The lower air pressure let the tire flex too much , flexing makes heat , on the way home I hit the supper slab and had picked up a flopping noise about 70 mph so I rode home at 65 and looked for anothe 145/80 tire .   I couldn't find one so I put a Commander II on it and got 20,000 + miles out of it. .   When it wore out I looked again for a 145/80 with no success , so I got a 145/60-15    --- wrong --- the tube wouldn't fit in there  :'(    now I've got a 888 back there and a 145/60 in my shop.  If I ever go tubeless I'll use it  .   But That car tire blew up to 30-35lbs. is a mighty good thing !    Good luck on finding one !  

Now if your willing to do some modifying , 155/80-15 can be had !