Air can hurt you too /
Some people say not to worry ’bout the air /
Some people never had experience with air
– Talking Heads, “Air”, Fear of Music, 1979
I have lots of time to think about things while I ride. Of course. I have nobody to talk to other than myself, and I can only sing to myself so much. I find that I spend a lot of time thinking about air, specifically the ways it interacts with me on my motorcycle.
I first remember thinking about this in 2005, during my first extended motorcycle trip. I was riding south on Hwy 97 in Eastern Oregon and, after being buffeted about by yet another semi, I started thinking about turbulence – specifically that of large blocky vehicles such as semis, RVs and trucks with big trailers. I want to see video of a semi riding through a cloud – of fog, smoke, whatever. This would a) be very cool to see and b) help me understand exactly what’s going on.
Interacting with the air off of large vehicles can be wild. It feels to me that there’s a wall of laminar flow – like the clean wave off the bow of a boat – immediately off the cab of a big rig, which gets turbulent pretty quickly as it passes down the side of the vehicle. Behind one of these large vehicles, the air is even more turbulent as the two streams of already-turbulent air collide.
Of course, this makes for interesting riding no matter how you’re experiencing it. Hitting it head-on (when passing a truck in the opposite direction, for example) tends to push the bike away as you go through the laminar, then buffets as you travel through the turbulence. Passing when in the same direction of travel is the reverse – there’s an odd shift toward the centerline as you pass through that laminar wave. And then there’s riding behind, which is a lot like hell.
As I crossed the Southwest and the prairie, I got a lot of experience with air of a different sort: wind. There’s that old traveler’s prayer:
May the road rise to meet you,
May the wind be always at your back.
May the sun shine warm upon your face …
So far, not so much wind at my back. In my face, broadside, 45° to my front or back? Plenty of those.
Other than riding directly into a strong wind, it turns out that it’s not so tough to handle. I learned a long time ago to just lean into it (crossing the 520 bridge on days of high wind on the lake), but that wasn’t working so well for extended distances. Finally, after several days in a row of strong winds, what I finally came to realize is that only the bike needs to lean, not me. As the wind ebbs and flows, shifts directions, whatever, I can just relax into it and allow my motorcycle to move underneath me, as I remain essentially upright. The alternative – being uptight, I guess – results in me fighting the wind. Which is pointless. If you fight the wind, it will eventually win.
And that doesn’t sound like an appealing option to me.
Comments
5 responses to “Air”
There is a Neil Young song with a line “Riding through the very air she breathes”. Every time I hear that I am moved by the simplicity and depth of the phrase.
Ah, yes, Unknown Legend:
Yeah, great song, and apt reference!
And this is why fluid dynamics suddenly became incredibly potent to me back in college. I always wondered why passing a semi seemed so precarious and why I was always pushed to the side when passing them. It turns out it’s physics. Who knew? Love reading your blog and seeing what you’re up to!
After a few years of negotiating semis at high speed on my bike I never used to know what drivers were talking about when they claimed to be getting “blown all over the road” on a windy day. It’s all relative I guess.
I seem to recall that, when a large truck was approaching, I would veer to the right a bit and then steer back toward the center just as I passed the truck. It’s been a long time.
Kevin, I do the same. If the semi is traveling at over 50 or so, I also tend to lean forward to slice through the turbulence zone a little more cleanly.