http://lifeisaroad.com/stories/2004/10/27/theDarkSide.html
25 years ago, a tire for my car cost $35 and lasted about 30,000 miles. Occasional failures of tread or bead/such were expected, but not frequent.
Today, a tire for my car costs $90 and lasts 70,000 miles. Failures are unacceptable and very unusual and are covered by extensive warranties. We've tripled the price and more than doubled the miles. In addition the technologies have made them handle better in cornering, wet-traction, braking, and heat-shed than ever before.
By contrast, 25 years ago, a tire for my motorcycle cost about $20 and I could expect it to last 8000-10,000 miles. Failures were common and there was no warranty coverage beyond the first install. The tire maker would provide instructions and materials on the safest and permanent way to repair a simple puncture.
Today, a tire for my motorcycle costs just over $200 and I can only expect it to last 8000-10,000 miles. The price is 10 times higher and I can expect no additional miles. Failures are frequent and there is no warranty coverage beyond that it will hold air when you first install it. The manufacturers will look you in the eye and inform you that there is no-way, no-how that a single puncture can be repaired-throw the tire away. Although there have been technology improvements in the super-gummy race-bike tires, the cruiser tires perform about the same as they did when I started riding.
My point here is that motorcycle tires for my street bike are 25-year old technology, at prices we should not see for another 50 years when compared to car tires. They've got us, and they know it. Why develop new or keep prices competitive, when folks will (must) by the **** you were putting on the street 25 years ago? Simply, we are a niche market. A manafacturer will sell more car tires in a day, than motorcycle tires in a lifetime. Their R&D money goes to the car tire market. The meager development done in the motorcycle world is concentrated on the race circuit, where the publicity really is. Those tires are doing truely amazing things, but are not suitable for the street.
Tires developed for the high-performance, low-profile street cars of today, particularly for the custom/performance sect have the sizes and characteristics (and quality) that make them a possibility for this project.
Over the years I have experienced every kind of failure imaginable on motorcycle tires. Defective beads, bubbling, blistering, cracking, tread/carcass separation, radical balance deficiencies, out of round, wobble, and just the outright failure to actually hold air have found their way onto my machines. Just for the Valkyrie alone I have personally seen failures in the three top brands available to us (there are few other choices). By contrast, I have not had a single tire defect on any of my cars in the same period (and as many miles). This also includes trucks and their tires, which I abuse with reckless abandon.
The other difference is in what I'll call "bump steer" Varying terrain, such as a ridge on the road, a track in a dirt road, or an angle or crown to the road will give much more feedback than they do on a motorcycle tire. The bike will have the tendency to turn downhill. At highway speeds this is not an issue (not felt), at lower speeds, again, it requires a firm hand on the handlebars and the bike remains well behaved. It is just telling you what it feels on the road. You feel the steering inputs, you do not have to accept them. I prefer the feel, as it puts me much more in touch with what's going on with the road conditions.
The bike turns as aggressively as it ever did. This has not impacted my speeds or angles of lean in turns. I can still drag pegs when I want to, and it has not slowed me down a bit. I am much more confident in wet conditions and with hard braking.
What about grooved pavement?
I found it to be an improvement, although the Valkyrie has always been well behaved. Grooved pavement does not bother me a bit with this tire. Neither do ridges or other pavement irregularities. My friend (on his XS1100) and I got into some of the worst grooved pavement I have seen just a few days after installing my first one. He was very uncomfortable, getting tossed around quite a bit. The Valkyrie did not care. I could feel it, but went straight and comfortable down the road. I also traveled many iron-grate bridges on my Alaska trip and was very confident and comfortable.
What about dirt/gravel roads?
The bump steer comes into play, but overall the bike is stable and well behaved. I found that my speeds went way up on the same roads after I installed the car tire. On gravel/dirt the bike gets more stable at higher speed with the car tire, whereas with the motorcycle tire it seemed to get less stable the higher the speed. Note that I have always been comfortable on gravel/dirt roads, even on the Valkyrie. Alaska was the real test, I traveled hundreds of miles on gravel, sand, and mud. The Valkyrie ate it all up and begged for more. It was not unusual to find me doing in excess of 70mph on open stretches of the roads. Look here.
You're gonna die a flaming death. You can't drive on the sidewall!
Hmmm . . . you're right, I can't drive on the sidewall. I'll keep you posted on the flaming death thing. No matter how far I lean the Valkyrie, I am never on the sidewall of this tire. It has molded in markings and the "rubber ****" from the mold process on the sidewall, and they remain pristine, untouched condition despite some very aggressive turning. I also set the bike over on its crash-bar one day to see where it rode, and it is not on the sidewall. All remains on the tread, and there is plenty of it. The contact patch of the car tire flattens on the bottom (as it is designed to do) keeping more half the tread on the pavement, even in full out, peg-dragging turns. The contact patch for the car-tire exceeds the size of the contact patch on the the only MC tire I had measured on this bike (Avon). An easy and fun way to measure is to find a street where water is running down it, that is otherwise dry (somebody watering the pavement again, a common thing here in Texas--I think they want it to grow). Ride the bike through the water and then into immediate peg-dragging turns. Then go look at the tracks. You'll be surprised.
How about braking?
I have much more stopping power with the rear than before. As always, your fronts are your primary, but the back helps substantially. I would guess that I could out-brake most other Valkyries, and it should be noted that the Valkyrie, as compared with the rest of the cruisers, has outstanding brakes to begin with.
It's flat! How can it turn?
Well, it's not really flat. This tire has a profile; it is just not as radical as the motorcycle tire. Remember that it is the back tire's job to stabilize the bike, in turning it is the front tire's job to de-stabilize the machine so it can lean into the turn. With the different profile, this back tire is just trying a bit harder to stabilize me. It does not reduce my turning response or authority. My line and speed into hard corners is unchanged, and I have the added benefit that I can absolutely slam the throttle exiting the curve without so much a squiggle. The Valkyrie on the stock tires or the Avon rear would spin it out from under you, resulting in all sorts of unpleasentness. One more advantage is that "flip-over"...that is, coming out of a hard turn in one direction to a hard turn in another direction is substantially easier and faster than on a standard tire.
It'll blow off the rim. The beads are different. Fiery death thing again.
Untrue, the beads are the same. This tire is designed for this type of bead (the Valk rim/bead is identical to the rim/bead on the aluminum wheels on the wife's car. In addition, the tire's specs approve it for this width of rim (the Valkyrie rim is 16x5). As long as there is air in it, this tire isn't coming off.