A roadie or a physics student might parse the circumstances based upon four factors: a light bike, heavy backpack, 10 percent grade, front brake.
To put it more directly: I took a pretty spectacular spill on my bike.
I am really surprised that I was not badly hurt, though everything did hurt for a good while later. Ironically, the same oversized rucksack that contributed extra inertia to my 9 point vault over the handlebars had also made my silhouette irregular enough to prevent me from rolling more than a few revolutions down the ludicrously steep pavement.
No other factors were in play: just me, gravity, and the left brake. There I lay like a flipped turtle in the middle of empty Chestnut Street, San Fransisco, between Larkin and Polk in the wee hours of the morning.
And in this state, I had the silly recollection of Pauli Shore trying to milk a cow, which promptly dumped bowel and bladder on his head.
“Oops,” he muses wearily, “Wrong button.”
It seems the Caltrain gets more first-timer bicycle commuters every day. I’m still learning myself, and see that cycling to work has pitfalls that are not so obvious. I gleaned from this experience some valuable lessons about handling descents under load, which I offer to you fledging commuters:
Consider investing in a sturdy rear rack and sensible panniers. You can expect this installation to cost no less than $100. A low center of gravity will make your bike handling less nimble, but much more forgiving. Things to avoid are panniers that will smack against your heel as you pedal. It’s really distracting, and will negatively impact the effectiveness of your stroke. Bonus- no more sweaty back or upper body tension.
Understand that the front brake has significantly more stopping power than the back brake. When you lock the front wheel, it acts as a pivot point, and inertia carries the vehicle around it. Stunt drivers use the same principle swing through tight corners at high speed. When cycling down a hill, the bike will simply pivot vertically – right over your head. Internalize which brake lever belong to which wheel, and apply brakes evenly to control speed when going down hills. It’s also important to adjust your speed before beginning to turn, because your contact with the road is a great deal less when the bike is tilted. Ride within your ability.
Don’t take chances when there is cross traffic. Stop. every. time. If I had a nickel for every time I kept pace with a stop sign coaster, I could buy a custom plate saying, “I stop at intersections, and you got passed!”. You probably wouldn’t shave any appreciable time off your commute, and it makes every cyclist look bad. If you want a speedy commute, just ride faster. It’s good for you.
To help keep your back wheel on the ground, you should adjust your riding position to the rear when careening down declines. Stand up and lean back until your elbows are almost straight. If you are turning through a curve, keep a habit of raising the inside pedal to the twelve o’clock position. This will keep the pedal from hitting the ground as the bike leans into the turn. Failure to do so may damage the crank or pop the back wheel off the ground, which naturally negates any further attempt at handling.
I hope you benefit from my silliness. Be careful out there, and enjoy the ride.
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