SHEESH.
My 2008 C14 with the CAR TYRE on it and the "REAR ONLY" tyre on the FRONT is parked outside in the hotel lot as I type this. Guilty as charged. Still.
Feel free to ignore the comments from folks who have no experience with running a CT, but seem pretty sure they know ALL ABOUT IT. Hell, ignore this post if you like. But I have well over 100,000 miles on CT in the last five years alone, so maybe you will find something useful here. I do not know it all, but I am a scientist at work and when I got interested in "the CT thing", I read everything I could find, started talking to everybody that had tried it, and started measuring tyres and such.
First, the rear tyre on the front thing. The idea is to find a REAR tyre in the FRONT size. Folks, read that a few times before you get out the flamethrowers, ok? The main difference between F and R? NOT the rubber compounds...NOT the carcass construction...sometimes the tread patterns are similar, sometimes quite different...the main difference is the tread is much thicker on the REAR. So you put a REAR (in the correct front size) on the FRONT in order to extend tire life. I have a 130/70R17 right now. Yeah, I know...
Next, the main event...CAR TYRE on a C14. I have two C14s. Pirelli Angel GTs on one, Bridgestone BT45 REAR on the front, and the evil CT on the rear of the other. I have almost 80,000 miles on CTs on the C14, and ran a CT for over 35,000 on my C10 before that.
There are lots of "FAIRY TALES" about contact patch size and shape, rim shapes. tyre sizes, safety, cornering, and $$. Some of them are already in this short thread. There are a few facts, too. The 100,000 miles is a fact. We live in the mountains, so EVERY ride begins and ends with high speed twisties. I wear out the edges on the fronts and throw away lots of center rubber every time. I ride at a pretty good pace, but do not race on the street. Wore another set of footpegs out last year and had to get new. (the CT and the REAR on the front are taller than stock, so there is even more ground clearance than stock!). I do not ride like a beginner or somebody on a bike that can't corner decently. Or a guy on a Gold Wing. The CT does not handle like a Moto Tyre, but it is not so different either. It takes a little getting used to. I ride a lot, and do not own a car. All weather, even when that kinda sucks. The CT is the least of my worries.
I can go around corners as fast as I want to anytime, and I usually like faster better than slower.
Facts!
I do not run a CT because I am cheap, but because the heavy duty carcass is so strong. After my last two Moto Rears picked up nails, and then failed SUDDENLY, in the dark, a long way from home, I decided to take a chance and try the CT for a long distance competitive rally I was going to be doing. I expected the CT to suck, and to be a bad idea, and to change it out right after that rally.
But I tried it anyway. You can see how that worked out...
I expect the CT will stay on the rim a lot better than a Moto Tyre in the event of a sudden blowout (that last bit is opinion). But I have not had such a blowout. My last CT had three small nails in it when I took it off. I did not even know they were there. Still had about 2mm tread depth, but it was time for a new one. It still held air, and I had gotten a little too comfortable with the reliability of the CT. I have to remember to check the CT all the time so that does not happen again. A Moto Tyre might have been fine like that too, but I expect it would have blown out on the interstate from the first nail. I REALLY hate getting flats at night, or in the rain, or a long way from home. I carry a compressor, sealant in a can, and "gummy worm" tyre plugs all the time. I only seem to use them on Moto Tyres on other people's bikes these days.
I have begun to think of the CT as "a better, safer tyre that lasts a long time". It stopped being an experiment a long time ago. The CT rubber is actually SOFTER than any of the Moto Tyres I have measured (flame me after you have measured lots of tyres with a durometer like I have, ok?). A physicist will tell you that softer rubber will give you more traction, and that the tyre contact patch size and shape DO NOT MATTER ONE BIT.
I AM a Physicist.
I measured tyre contact patches on the two C14s. One with the CT, one with the Angels. The contact patches are almost exactly the same size for both C14s (no surprises there). Then I got some heavy tie downs to hold the bike up, and measured the contact patches with the C14s leaned over. Not exactly like flying through a corner at speed. but I had a budget of $0, and an afternoon, and some quadrille paper. I was a little surprised when the contact patch went from short and wide to long and thin as I pitched the C14 with the CT over, AND STAYED THE SAME SIZE. No matter what the angle!
Oh, by the way... I (still) DO NOT RECOMMEND RUNNING A CAR TYRE ON A MOTORCYCLE TO ANYBODY. You should probably take your C14 to the Kawasaki dealer and have them put on approved tyres in the correct sizes every time.
I do recommend making informed decisions, not based on hysteria.
Folks can say what they like, but lots of folks are just making **** up. Which is fine, but you should know that. The stuff you will hear about contact patches and tyre edges and traction is mostly just guessing, and mostly just wrong. But it is late and I have posted all that on this forum before. Search for it if you like, or send me a message if you want to read more.
dat
sax
man