Tuesday, September 20, 2011

50mph: Breaking the speed limit on a bicycle

(ABOVE: Speed limit 40mph? Ooops...)

One of the steepest paved roads that you'll find anywhere is right here within the city limits of Tulsa. I took advantage of it and zoomed to my fastest speed ever on a bicycle.

Previously, 47mph was my all-time top speed. I reached that speed three years ago on a down hill during the Tulsa Tough. I got competitive and was "being a boy" as I raced a friend. I haven't been close to that speed since.

(ABOVE: The huge hill is near mile 12 of my ride along Elwood Drive.)

Elwood Drive between 61st and 71st features a sudden downhill plunge from Turkey Mountain.
Topography maps show a short, steep 200 foot drop in less than a quarter of a mile. You very much get a "falling off the edge of the world" feeling if you drive it.

The opportunity was perfect to try Elwood hill on a quiet September morning: sunshine, no wind, and barely any traffic at 9:30am. The road is smooth and straight.

But to race to the bottom I first needed to climb to the top!

I pulled out of Turkey Mountain park and headed north toward the hill's increasing slope.

On approach the hill appeared to rise straight up. The increasing slope added weight. Each pedal stroke proved a deliberate effort. I felt like I was pulling a car with my bike. I was tempted to walk it, but I had to keep going. I would roll backward if I slowed down or tried to get off the bike!

(ABOVE: Near 5% where I'm standing the Elwood/Turkey Mountain hill rapidly increases to 20% grade for about 150 feet.)

I cranked up the hill at a walking pace in my easiest gear. The worst of the climb thankfully stretched only 0.1 miles. I wouldn't have made it much longer!

I reached the top of Elwood/Turkey Mountain with my lungs on fire. I collapsed on a giant rock to catch my breath.

I checked my GPS: near 20% grade! I smiled as I set a new personal climbing record easily surpassing my previous mark of a 15% grade. I learned that 20% is near impossible, but I made it!
For comparison, that's nearly twice as steep as Yale Avenue between 81st and 91st in South Tulsa.

Now for the fun part.

(ABOVE: Looking southward, I waited for the few cars to clear before zooming down. The edge of the hill comes quickly.)

I first double checked my bike: brakes good, wheels straight, tires clean. And helmet snug.

I waited until no cars were visible. With the road clear I positioned my bike in the middle of the road, snapped into my pedals, and pointed my front tire straight down. I released the brakes.

My bicycle rapidly accelerated without pedaling. I tucked into a ball to reduce resistance. Within seconds: 20mph, 30mph, 35mph....

I took my eyes off the speedometer to concentrate on the road.
I steered in a perfect line nearly down the center of the empty road. Completely focused and perfectly smooth and very fast.

A thunderous river of air rushed through my helmet-- try lowering your car window at freeway speed for comparison. The scenery zoomed past me at what seemed like light speed.
I whooshed past the Turkey Mountain park entrance in violation of the speed limit. I knew I was well north of 40mph.

The hill flattened, and I braked gradually at first. I glanced down at my speedometer as it dropped below 30mph. It took a while to slow down!

How fast did I go? I checked the GPS in my pocket: 49.53mph. Wow!!!

I don't plan to break this personal record again, Wifey might kill me before any bicycle would.

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