Return To The Darkside

Here’s the problem with writing for public consumption: you never know when you’re going to accidentally touch someone’s third rail, so to speak.

Two years ago, I wrote about the practice of “ darksiding” for Road & Track. I doubt most of you have heard that term; it refers to the practice of putting a passenger-car tire on the back of a heavy touring motorcycle like a Honda GoldWing. When I wrote the piece, I had no particular opinion about the merits of “darksiding”; rather, I was focused on the idea that exhaustive, high-budget development often makes it possible for a bad product (or a bad idea) to triumph over better products/ideas that don’t get that same amount of development.

My failure to hysterically excoriate the “darksiders” led a couple of wannabe motorcycle writers to mount a spectacularly ineffective harassment campaign against me, trying to get me fired from my job and/or removed from various media outlets. The sum total of it was that I got kicked off Facebook, which in the long run has done me more good than harm. I haven’t given “darksiding” much thought since then; none of the seven motorcycles my son and I collectively own would benefit from a passenger-car tire. Furthermore, I only ride eight or nine thousand miles a year, not really enough to make an economic case for darksiding even if I had a proper touring bike.

If a recent thread on Reddit is any guide, however, darksiding hasn’t disappeared just because I forgot about it. To the contrary; it’s stronger than ever. And while there are sound scientific reasons why it’s a terrible idea, considering those reasons in depth exposes one of my favorite flaws in what I (sympathetically) think of as “the Asperger’s mindset.”

Here’s the problem: Motorcycle tires are garbage. All of them. There isn’t a single bike tire out there that even comes close to matching the standards for durability, wear, and quality set by passenger-car rubber. The most hilarious example of this is the fact that Carl Reese’s 38-hour “motorcycle Cannonball” last year had to include a stop to replace the rear tire just three hundred miles from the finish. That’s right: you can’t ride a bike 2,600 miles at speed without killing your rear tire.

The bigger the bike in question, the more unsatisfactory the tires are. GoldWing riders complain that they can’t get 10,000 miles out of anything. Think about that. It’s been more than 25 years since any passenger car had those kind of issues — I’m thinking specifically about the first-generation Acura NSX and the Porsche 993, both of which were notorious for murdering back tires in 5,000 miles or so. But those problems have been comprehensively solved by tire manufacturers. I currently have eight years and about 20,000 miles on the Goodyears fitted to my 993. They look fine.

The same kind of engineering effort, applied to touring-motorcycle tires, would probably yield the same results. But although motorcycles and scooters combined outsell four-wheeled cars on this planet, the iceberg bulk of that is low-power commuter machinery for developing countries. The “full-sized” motorcycle business is utterly tiny compared to even the sports-car segment around the world. I’m no Tim Cain, but no matter how I shake, rattle, and roll the numbers, I can’t account for more than maybe 500,000 big-bore motorcycles sold globally last year. (By “big-bore”, I mean 750 cc or above.) The tire-eating GoldWing has rarely sold more than 10,000 copies in any given year, worldwide. That’s the same kind of non-volume that doomed the Mazda RX-8 to extinction, you know. No wonder there hasn’t been a new ‘Wing since the days of the 385-horsepower C5 Z06 — and no wonder nobody’s knocking themselves out trying to make a perfect tire for it.

So the darksiders use car tires, and they get five times the highway mileage out of them, and if there have been any safety consequences to anybody, they’ve been lost in the statistical noise that surrounds motorcycle injury statistics. Given the frequency with which riders are injured or killed by inattentive drivers, worrying about rear-tire-related fatalities while you’re riding a ‘Wing seems a lot like BASE-jumping with one of those Japanese-touring allergy masks on. Yet people worry, and some of them really worry, and one of them has gone through the trouble of producing an absurdly comprehensive argument against darksiding, using everything from equations to actual cut-away rims and tire sections. When I read said argument, I was utterly flabbergasted — and completely convinced that automotive tires have no place whatsoever on a motorcycle.

The anti-darkside argument is flawless. Automotive tires are not built for the pressures and stress of motorcycle use. The bead shape is all wrong, and the mechanism of cornering works to further weaken the already indifferent air seal formed by the mis-junction of tire and rim. The casings are not sufficient enough to narrow pressure zones. The heat concentration at the shoulders is overwhelming. The very squareness of the tire prevents the motorcycle from steering correctly. All of this is proven in the most comprehensive, detailed, equation-laden manner possible …

… but there’s just one problem.

Eppur si muove, motha-‘uckas. Car tires shouldn’t work, but they do work. And they work fine. Which either means that we live in a world of magic or the Bumblebee Argument applies: to wit, the existing calculations and measurements are insufficient to truly describe reality as it exists. This is the kind of thing that trips the Aspies of the car and motorcycle world up a bit. I’m not being critical here; anybody who used to commit entire 500-line AtariBASIC programs to memory the way I did as a child is certainly a member of the autism spectrum himself. I’m just observing. And what I observe is that Internet scientists are very good at clinging to certain facts, figures, or results, but they are very bad at stepping back a bit and making a conscious observation of those cherished facts, figures, or results.

The detail-obsessed Aspie can tell you that the motorcycle rim is incompatible with the car tire; the conscious thinker observes that it seems to work just fine for millions of miles on GoldWings. The obsessive physicist can quote chapter and verse about car tires and the way their ply-wrappings are incompatible with motorcycle-induced stress; the self-aware rider operates the bike just fine. The Internet expert can use equations to show that a motorcycle can’t corner correctly on a square tire; the man by the side of the road on Route 129 has photos of bikes dragging their pegs on $69 Chinese passenger-car tires. It’s the duty of any genuine intellectual to admit defeat when the real world contradicts his beliefs. To behave any other way would be to sink to the same level of the cardinals who persecuted Galileo.

I’m reminded of the debate that raged when I was younger between the proponents of the Motorola 68000 series of processors and the defenders of the Intel 286 and its successors. I was a Motorola/Mac/PowerPC bigot and I remember lecturing people in computer labs about the superiority of the instruction set and the purity of the architecture and whatnot. I was absolutely right. But what I couldn’t have predicted was that Intel and AMD would throw so much money and effort at the x86 architecture that eventually even Apple would give up and come on board. The computer-hobbyist reader might protest that the modern Intel processor has about as much in common with the 386DX as it does with the 6502; I’d reply that the modern car tire has about as much in common with a ’70s bias-ply passenger-car radial as it does with the tires used on the Mars rover.

Like it or not, darksiding is here to stay. The only way to stop it would be to design and produce motorcycle tires that meet the same durability and price standards as the darkside automotive rubber. But since that’s real science, and real science is hard, expect the anti-darkside crew to continue doing battle on the Internet instead of in the laboratory. And don’t be surprised when the technologies that win the day in our automotive future wind up being the technologies that sell in enough volume to make their refinement and expansion both practical and profitable. That is the real Dark Side: accepting that reality doesn’t care about your cherished opinions, no matter how much fuss you raise.

[Image: jojovols/Photobucket]