Friday, August 6, 2010

TAR SNAKES – A BRIEF NOTE ON SAFE MOTORCYCLE OPERATION UNDER REALLY SPECIFIC CONDITIONS

THEY APPEAR MOSTLY IN THE SUMMER. And mostly in the afternoon. They are very disconcerting, even dangerous.

I’ve driven a motorcycle with a flat rear tire, more times than I’d care to count. The handling becomes dangerously imprecise. There is no cornering. And, pretty soon, the back end moves around like a Zamboni on an ice rink but driven by a drunkard. Sometimes I encounter a very similar phenomenon, yet the rear tire is properly inflated. Each time I stop to check, my tire is properly inflated. What is this all about?

I asked Dave, my resident sales guy at A&S, if, when riding his BMW GS, he ever encounters a rear end that seems as if it wants to, at least, unnerve him and at worst, kill him. His response? “Tar snakes.”


I NOTICED A MARKED INCREASE IN TAR SNAKES upon returning to California after touring five other western sates. We’re pretty hip about building new roads, but a whole lot less enamored with maintaining them – because, after all, road repairs require tax dollars and taxes are a drag on the economy. A quick and cheap fix to cracked pavement is trace developing surface fissures with hot tar. With tar sealant on worn roadways, the surface begins to look like a map of eastern Europe prior to the break up of the Soviet Union: a lot of little non-descript areas bordered by random black-lines. The tar seeps into the crack and seals the opening so that water cannot collect and settle inside, expand and contract with freeze and thaw and, ultimately open up a jillion miles of mini grand canyons cris-crossing our pavement. The tar also keeps plant seeds that blow into the cracks from germinating and breaking the tarmac.

The road guys apply tar sealant at a slightly warmed temperature so that it may easily be manipulated and routed into the offending ruptures in the road surface. It quickly cools, sticks and seals.

The cracks tend to develop where the road surface is most heavily used, thus it is not uncommon to see long, irregular lines of tar wriggling parallel to the direction of travel right where the wheels of automobiles and trucks route themselves.


HEREIN LIES THE PROBLEM. We motorcyclists normally use the innermost car tire path as we travel. Such positioning allows us two outs in the event of an emergency: to the right of our lane should something occur to the left and to the left – dangerous, on-coming lane – should something occur in front of us or to our right.

Physics reminds us those materials of different densities heat and cool at different rates. Physics also tells us that black surfaces absorb heat while lighter surfaces reflect it. Thus, on hotter summer afternoons and evenings, the tar heats, melts and becomes slippery. And the Tar Snakes become active, their nasty black forked tongues slipping in and out of their mouths, sensing our approaches and salivating over how nice a bloody ankle or shin would taste.

Bending into a sweeping turn on a canyon road and having that rear tire placed atop the run of tar transforms an enjoyable turn into an adventure. Too much so. The rear tire wants to slip out of the chosen line. Centrifugal force? When the rubber finds dry surface, it urges the bike to stand upright. The rider wants to lean and correct, thus pulling the tire back on the gooey surface. It’s a battle of wills that if the tire doesn’t win, the Tar Snake does.

There is no sure-fire, safe solution for driving when the Tar Snakes are active in the mid-afternoon. Strategies must include:

1) Slow down,
2) Seek a path between the tire lanes,
3) Allow the guy in the Buick behind you to pass, and
4) Forget about the view of the canyon! Watch the road.

A fifth strategy would be to understand that, like all other services we demand in California, if we want good roads, we’d damned well better decide we're gonna pay for them.

© 2010
Church of the Open Road Press

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