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By admin, September 7, 2007 8:50 pm

by Stephen Herrick

The end of Daylight Savings, and the beginning of dark by 5 o’clock is enough to make any cyclist trade in their Gatorade for a bottle of scotch, but we just might have a way to take the sting out of it. June and I, and another friend took off last Sunday and drove up 101 to Windsor for a ride through some of the premier vineyards in Sonoma County. The leaves were turning their fall colors, the weather was crisp, but not too cold, and the countryside was absolutely gorgeous. I’m from New England, and believe me, I’m not easily impressed with fall foliage unless it’s truly something special. We had such a good time that we have decided to make it an annual event on the Sunday when the clocks “fall behind.”

We started out on Old Redwood Highway just north of Santa Rosa, and climbed up Chalk Hill. (A piece of cake when you’re not coming at it from the opposite direction after 80 or 100 miles on the Wine Country Century!) Then out the back roads to Geyserville, where the local schools were putting on a Fall Colors Festival with antique classic cars, barbeques, and a chicken-poop lottery. We had lunch, and then crossed over Highway 101 and headed back on West Dry Creek, and Westside roads. A quick stop at a couple of wineries, (it is the end of the season after all,) over the Wohler Bridge, and we returned to Windsor. A nice paced metric century with just over 2000 feet of climbing, and of course, the spectacular scenery. We modified it a bit, but a full description of the basic ride can be found on the Santa Rosa Cycling Club’s website at http://www.srcc.com, under “10 Great Rides,” “Alexander Valley and Russian river Valley.”

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By admin, September 7, 2007 6:41 pm

by Stephen Herrick

Suppose a Diablo Cyclist wanted to train hard enough that he/she could start at a point exactly 15 miles from the summit of Mt Hamilton (say at Amy’s Rancheria,) ride to the top, and then return exactly the same way and have an average speed of 15 miles per hour upon his return.

He/she goes out as hard as he can, and checks his cyclometer as he makes the turn at the observatory before heading back down. He’s got an average speed of 7.5 miles per hour so far.

At what average speed will he need to ride the descent back to the start in order to finish with his target goal of 15 miles per hour for the compete out-and-back?

Well, it’s a trick question really. He can’t get his average up to 15 miles per hour unless he can teleport instantaneously back to the start.

Here’s the deal. Average speed is determined by the distance you travel, divided by (per) the time you take to do it. However, if you average ½ of your target speed over ½ of your distance, you use up all the time you’ve allotted yourself to complete the entire trip already.

Plug in some numbers, and it gets easier to see. It’s exactly 15 miles from the start to the summit, so an out and back would be a total of 30 miles. If you want to finish the whole round trip with an average speed of 15 miles per hour, you have to complete the ride in 2 hours. But if you average 7.5 miles per hour for the first 15 miles, then you’ve already taken two hours!

Or, for the mathematically inclined, d (distance) / t (time) = v (velocity or average speed)
Flip that around you get, d/v=t.
But, 1/2d / 1/2v also = t.

Try something actually doable for all you daredevil descenders. Say you start at the same point 15 miles from the top, and you’ve got the same goal of 15 mph average, so you have 2 hours to complete the ride. You check your cyclometer at the top and you’ve got a respectable 10 miles per hour.

Okay, it took you one and ½ hours to climb to the summit (15 miles at 10 miles per hour, congratulations.) Now you’ve got to make the return 15-mile trip in ½ hour. That requires an average speed of 30 miles per hour. Watch it on the hairpins!

But say you get to the top and you’ve got an average of 8 miles per hour. Well, riding 15 miles at 8 mph means it took you 1 hour, 52 minutes, and 30 seconds to get there. Remember, to average 15 mph you have to complete the trip in 2 hours, so now you have only 7 and ½ minutes left to get down. Let’s see, 7.5 minutes to go 15 miles would require an average speed of 2 miles per minute, or 120 mph! I don’t think you’re going to make it.

The moral of the story is; you can almost never recover your average speed after climbing up a long hill merely by descending the other side.