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Click here for an update on 12/1

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Click here for an update on 2/13/06

Click here for an update on 5/16/06

Click here for a pic of the tire in the Dragon

The boys riding Valkyries have been riding the "Dark Side" for years.  Replacing a motorcycle tire with a car tire started out being a way to get more mileage out of a rear tire.  It has turned into an arguably better ride.  Since I’m a sucker for things that sound like a good idea, I decided to join them.

A stock Goldwing tire is slightly smaller than the Valkyrie's but the Valkyrie tire will fit the ‘Wing.  (In fact, with the larger tire, the speedometer and odometer read more accurately.)  The reports from Valkyrie riders say 205/55R16, 205/60R16, and 205/65R16  tires fit their bikes.  My car has 205/65/15’s so I took one of them and put it in the rear tire well.  At least I tried.  I couldn’t even get the tread past the axle. 

The best size for the ‘Wing would be a 185/65R16.  Unfortunately, I can’t find one.  I can find several 195/xxR16’s.  More problems – most of them have asymmetrical tread patterns.  I found six 195/xxR16’s with symmetric patterns (although I have reports of Valkyrie riders using asymmetric treads without problems).  Two 195/80R16’s were for dually trailers.  Goodyear has a “W” speed rated 195/50R16 called the Eagle FS1.  It would work but is a little over a half-inch shorter then the stock ‘Wing tire and the speedometer error would be worse.  Bridgestone has a Blizzak WS50 that is only speed rated Q (to 99 MPH).  That left two tires – the Goodyear Eagle Ultra Grip GW3 and the Dunlop SP Winter Sport M3 – in 195/55R16 sizes.  Both are actually snow tires and have very similar tread patterns.  Both tires also come in a run-flat version.  Given my knack for collecting sharp objects in my tire, I figured the run-flat would be a good idea. The stats on the tires are below.

Dunlop E3

Goodyear Eagle Ultra Grip GW3 EMT
Dunlop SP Winter Sport M3 DSST

Goodyear Eagle FS1

I went to the local Discount Tire center to order the Dunlop since it was a few bucks cheaper.  Sweat dreams- they’re basically sold out for the season.  We did find two Goodyear GW3’s so I latched on to one of them for $165.  Without run-flat technology, it would be about $40 less.

As soon as I got it home, I put it into the wheel well.  It took some wiggling to get it in and it just barely rubbed both sides.  Without being on a rim, the beads are 6” apart.  The ‘Wing has 5 inch rims.  When I squeezed the beads in to 5”, the sidewalls came in about an inch.  It should fit!

Discount tire wouldn’t mount the tire for me so I took it to the local Honda shop.  I also took the front wheel off since the tread on the left side is basically gone for about one inch all the way around.  They charged me a total of $252.08 for a new front tire (Metzler M880) and mounting and balancing both.  This is after I removed the tires from the bike.  That put me out a bit over $400 for the set; mounted and balanced.

Drum roll please!

Aaaaannnndd – it fits!  It went in fairly easily.  Coming out, it wants to hang on the area just above the bead.  The tire shape has a little lip right there which is intended to protect the rim.  The overall width after installing on the rim is right at 7.5".  I tried to measure the contact area by rolling the bike onto a ruler.  'Didn't work.  M'lady came up with the idea of taking a print.  I accomplished it by lifting the bike on the center stand, painting some water on part of the tire, spinning that part to the bottom, setting a piece of paper under the tire, and taking the bike off the center stand.  It took a few tries but I finally got it to come down without rolling.  A picture of the print is below.  (Click on it to get the full size 2MB version.)

You might have to count the inch marks but the red lines are at 5 and 7 inches for 35 square inches.  Unfortunately, she didn't come up with the idea until after I had got rid of the original tire.  If someone could do the same thing on an original 'Wing, I'd be interested in the results.

These next two show the tires side-by-side.

You can see how much more tread is on the ground.  I like the aggressive pattern of the auto tire and the siping helps control slippage on painted road stripes.

Initial impressions – it’s sweet!  Since the sidewalls flex, the ride from the rear tire is smoother.  I can ride over manhole covers, cracks, small potholes, and similar obstacles with much less jarring through the rear tire.  The passenger normally gets bounced around when the back end goes over a bump.  The softer tire really lessens that.  If I could put a percentage on it, I'd say about 50% of the jarring is gone.  Since the tire has a large flat spot even in corners, I can hit cracks in a corner and not be pulled around. 

It handles grooves better.  The front gets hung up a bit but the back just floats over them.  Rain grooves in freeways and construction on roads really point this out.  I  can even corner over cracks and it doesn't make a difference.

It does notice angled road surfaces.  If you are on the side of a rut, the bike will want to fall into the center.  It can be fun if you set the cruise and let the bike go.  It will start up one side of the rut, lean into the rut, and center itself.  Eventually, it will go up the other side and repeat the process.  For a while, you can just sit back and let the bike keep itself in the rut.  At some point, the road will turn or the rut will change enough where you will leave it.  You will really notice it if the road has bumps where a truck or two have pushed asphalt into a mount.  If you get on the side of the mound, the bike will really want to get off it.  Once you're used to it, you realize what's happening and find a flatter spot.

Blow-by-blow on my test ride.

On the freeway, I found the inherent pull to the left was mostly gone.  When I'm on the open freeway, I slip a leather strap on each side of  the handle bars, set the cruise, and use the straps to steer.  I am constantly pulling on the left one to counter the desire of the bike to veer left.  I believe the pull is coming from the drive-shaft.  As it spins, it would just as soon spin the bike around itself.  The torque leans the bike to the left.  With the flat tire, the shaft doesn't have as large on an effect.  I still need to make corrections every once in  awhile, but I don't need the constant pressure.

Switch-backs felt about the same.  I do find a greater confidence in the traction of the rear when I am cornering and have been putting a bit more gas to the tire in the corner.  It takes it.  At slower speeds, I can't tell a difference.

Dirt and gravel is much more stable.  The dirt road was in rough shape with wash-boards over an inch deep and lots of large gravel.  As before, the flex of the rear tire took about half the jarring out of the ride.  More importantly, it stayed on the ground and under control.  On the soft dirt, I could try the anti-locks.  With the stock tires, the anti-locks would kick in and eliminate most of my stopping power.  With the wider rear tire, the anti-locks still kick in but I retain most of my stopping power. 

I also got a chance to try some burn-outs.  Burnouts are probably not on the top of most 'Winger's list of pastimes, but sometimes the back tire will spin a bit.  It happens often on the white patches marking crosswalks.  My first test involved just such a marking,  I got centered on it, revved the engine a bit, and let go of the clutch.  The tire chirped a couple of times and I was gone.  It's a snow tire; it has siping to grab whatever roughness it can.  I tried it again on the dirt.  The back end squirreled around a little, but at 30mph, I was comfortable just leaving the throttle where it was and letting the bike catch up.  It did. A few days later, it rained so I tried the same test on the painted stripes of a crosswalk. I could get the tire to spin, but had to really open it up. When it started spinning, the bike did not have the usual fishtailing and desire to slide out. It just went straight ahead with the tire spinning. As soon as the tire hit pavement, it made a couple of screeches and took off.

Others have mentioned cornering is different.  Normally, you can steer a bike into a corner, get the lean angle where you want it, and basically let the bike finish the corner before steering out of it.  The sidewalls of the car tire flex in the lean.  This keeps more tread on the ground.  However, the sidewalls want to straighten up and straighten the bike up.  You have to keep steering all the way through the corner.  Good argument; but not real strong in my experience.  On some of the sweepers, I could feel the need to hold the corner.  Other times, I didn't find myself doing anything in particular. 

I can sometimes feel the sidewalls flexing if I hit bumps in a hard corner.  It can cause a small wobble but I've felt that on regular tires.  It is nice knowing that as you flex the sidewall, you are getting more traction. 

Acceleration is improved.  The rear tire used to slip easily.  This one doesn’t.  I don’t know yet if it will wheelie without a passenger but I’m guessing it will.  I've got the front end to pop up to the end of the forks and feel like the tire might have left the ground.  I'm not willing to run the bike hard enough to find out.  The rear tire will still spin if you drop the clutch so a solo rider would have to work on placement of the body as power was applied to the wheels to get the front end up. 

The real selling point – stopping.  During previous tests, I could get the ‘Wing from 40 to 0 in about 44 feet.  I got one stop on the new tire in 41.5 feet.  Not a huge difference.  However, I did get the front tire to lock a couple of times which has never happened before.  The rear used to lock up activating the anti-locks.  I need to spend some time relearning stopping with greater use of the foot brake.  If I can consistently get 40-0 in under 40 feet, I'll consider that worth the cost itself.

More to come as I get more experience on it...