Dark Side Motorcycling

The Triumph Rocket III Classic is a tire eater. I’ve been through 5 rear tires and there’s only 19,000 miles on the odometer.

Recently on my way back from Talihena, Oklahoma, Metzeler number five sprang a leak. Something had cut a nice half-inch slit right in the center.

At about $320.00 each, my wallet was as flat as the tire. I decided it was time to try life on the “dark side”.

“Dark side” is a biker term for running a car tire on a motorcycle. It is one of the most debated practices in biker forums, with folks on either side of the issue passionate about their opinions. Most of the folks who have tried a car tire on a large cruiser swear they’ll never go back to expensive proprietary motorcycle tires again.

I have just joined the choir.

I started by ordering a 225/55ZR -16 BFGoodrich g-Force T/A KDW 2 tire from TireRack.com. Since I’m in north east Texas and Tire Rack’s distribution center is only a couple hundred miles away in neighboring Louisiana, my $140.00 tire only took one day to arrive on my front porch for a modest $19.00 shipping via UPS ground.

The tire was as perfect as the picture I saw of it on the internet. Rolling it up beside the bike caused some doubt. At first glance I thought I’d ordered the wrong size. No way was my wheel big enough for that tire. But after a frantic bit of measuring and inspection it became clear that it was, indeed just the perfect size.

Removal of the Triumph Rocket III rear wheel is easy, as long as your car lift doesn’t get posessed by a poltergeist before you have the bike positioned and strapped on properly. But that’s all I’ll say about those terrifying few seconds, and I’ll just be happy someone in the shop had the presence of mind to throw a breaker before total disaster struck.

With the wheel off we rolled the flat Metzeller over to the tire machine and my tire guy expertly dismounted a tire in 15 minutes that people in the forums say is easier to just cut off with a rotary tool.

Then we attacked the big car tire and started wrestling it onto the rim. The two of us are pretty strong fellas, with the combined mass and attitudes of a Kodiak Bear on LSD; most men and a few large predatory animals would lose to the two of us as long as they didn’t bring any friends to the party. But that car tire was whipping our asses. We finally resorted to very tiny incremental progress on the tire machine, inching forward and back, gradually progressing along the rim until we had the new tire bead seated with no damage to it, the wheel, or our fingers. No air blast was necessary to seat the bead. Just a good fill up and everything popped into place. I set the initial pressure to 30 PSI and we slapped the new shoe on the bike, after cleaning and re-greasing the splines.

With all the nuts and bolts torqued to correctly converted Newton-meters, brake caliper back on the rotor and pads in position, we set bigfoot on the pavement and prepared for takeoff.

I’d been reading a lot of forum entries from guys who’ve already made this leap, and only two of them had done it with this particular brand and model tire. I was pretty sure this wouldn’t be a life threatening mistake, but I wasn’t quite sure whether it wouldn’t be any kind of mistake at all.

The beast waited, leaning much more casually on her side stand as if to say, “I could stand here all by myself without a kickstand if I really wanted, now.”

I donned my helmet and kicked myself for having forgotten my Vanson jacket and gloves. If something went wrong, I was wide open for road rash today.

I threw a leg over and stood her up. The triple fired off. I eased out the clutch lever and sprang away, straight ahead for a hundred feet, then purposely leaned into my first corner. It was good that I leaned purposely…because the back tire wanted to argue – just for a split second – about leaning over.

But it was a very weak argument. It instantly gave up and allowed me to control without any secondary protest.

It did so every time I leaned into a corner or curve…a feeling as if the was an invisible force field trying to hold the bike upright that would suddenly diffuse as you gave the counter steering effort just a tiny bit more pressure. By the second day I wasn’t even noticing it, except when I would wonder if it was still doing it and purposely feel for it in my next turn. It was not even a distraction any more after 100 miles of riding.

Stopping was a blessing. The back brake actually contributes to stopping now, with all the extra rubber on the ground, and the tire is in far less danger of locking up due to unnecessary pressure on the brake pedal. Taking off hard from a red light you feel the bike has gained power, as the added traction launches you into the intersection instead of breaking the rear tire loose to leave skid marks and expensive rubber all over the pavement.

1. Riding in stop and go traffic – I can cruise at 1/2 mile per hour straight as an arrow and keep my feet on the pegs while laughing at the wobbly duckwalkers on the other bikes
2. Curves and corners – I’m taking them faster now. I can feel more tread on the pavement and there’s no slip, period. I may form a different opinion when the weather gets cold and the rubber hardens up into something closer to diamond than the soft sticky racing compound of the Metzeller. We’ll see.
3. Stops and take offs – no worries about burning rubber, now I gotta worry about keeping the front wheel on the ground. Traction, traction, traction. And stopping? I can’t imagine what it would take to lock that back fatty up now.

1. The bike tries to follow groves and ruts, and the slower you’re traveling the more it tries to stay there. It’s easy to compensate, but is a little surprising at first.
2. Manual maneuvering of the bike takes a bit more muscle. She doesn’t roll quite as easily, and will tip quicker on uneven ground because you’re not able to balance on the center of the tire as you would with a motorcycle tire.
3. It takes slightly more initial counter-steering pressure to lean the bike into a corner or curve. But it’s very minor and within a day I wasn’t even noticing it any more due to second-nature taking over.

avatar William R slater

I Ran car tires on my bikes back in the 1988. On my 79. HD Low Rieder and my 73KZ 900 but all Wes put Bike Tire on front I just got side car for my. 2015 Moto Guzzi and I like to have information about going Darkside on the front wheel and

avatar nobu

Hello, Thank you for this article.
I have 06 R3C with same color and just hit 5000 and replaced to another Metz. It will probably end its life next summer. Then I am thinking about going Darkside.
I heard it’s difficult to find place to attach CT to MC Wheel. Could you share who can do the job and how much? I live in Richardson TX, so we must live in the same area.

avatar Tim Frazier

My riding style was even more aggressive when I had my Yamaha XS100, and I got a good 12 to 15 thousand miles out of my Perrelli rear soles back then, even with me pulling a wheelie every time I saw a pretty girl on the street. These fat Metzelers, and most performance MC tires these days, are just very soft for superb pavement grip, which sacrifices longevity.

All the other R3 owners I’ve conversed with have had similar short rear tire life expectancy. It’s pretty rare to hear anyone claim much more than 8,000 miles on one.

avatar Greybeard

I had to change the tire on my Yamaha XS1100SF at 19,000 miles. I know that’s out of the ordinary, but have to wonder…
Do you just twist that right handlebar more than usual? I know the bike is heavy and that’s certainly a factor, but five tires in that time? Wow.

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