Sunday, March 11, 2012

and the results of the gen light drag test are........inconclusive.

First off I must say I did not get the 100 miles in that I wanted to last night.   Second,  I did take the opportunity to test the difference in drag among my light configurations,  Handlebar lights + headlight,   Gen light turned off with handlebar lights and headlight,  and Gen light turned on with aforementioned lights turned on.

The testing ground was the front and backside of Usery Pass.   The front side to record a slower rolling speed and the backside to record the faster.   In the end it was a lot of trouble for not much information, yet I did glean enough to make an educated decision I think.

I must say it was a beautiful night albeit a little chilly.   If I had known how chilly it would be at the end of my testing I would have worn the full jacket from the start so as to make it an even test across the 6 trials.  My current light setup consists of the following-  2 Planet bike 2 watt  superflashes,  a 3 watt princetontec headlamp, and a killer generator light using the Shimano hub and a homemade light circuit made with 3 Cree leds (wicked bright)  and a circuit borrowed from a fellow Randonneur of Southern Arizona Randonneurs fame who few people get to ride with but on occasion he has slowed down and I have ridden with him up in the pines on the D3M permanent.

So,  I know you are curious about the results.  Interestingly enough, going down the front side there was only 2 seconds difference between the normal wheel and the gen hub when it was turned off (I'm kind of glad at this point I didn't blow the extra dough on the Schmidt hub,  I'll eat that extra second every 2 miles).  On the backside there was roughly 9 seconds difference but I think some of that can be attributed to the generator light creating more drag because of lost aerodynamics,  since that comes into greater play at higher speeds.   9 seconds over 4 miles still isn't too bad.  We are still only talking a few minutes difference on a hundred mile ride.

Now,  for when the light was turned on.  The bike actually was around 45 seconds faster on the front and 15 seconds faster on the back.  What you ask?  This spits in the face of physical laws of energy transfer and friction and drag yada yada yada.   Well,  it is funny you should ask.  You see,  before I started the last set of tests with the gen light on I made an interesting discovery.  The front brake was loose and as a result it had been rubbing since the spring was able to twist it sideways.   I must say I am amazed a brake that is rubbing lightly can cause that much drag.

The light can't be creating too much more drag I figure,  and surely the drag with the light off is not enough to ditch the comfort of a super bright and battery-less headlight for the longer rides.  I also wonder how long that brake has been like that.  Was it that way last week when I did the long ride out to Sycamore creek?  Was it there when I tried to hold on at the race a month ago?  Was it like that for the Jan 200k?  The Mt. Lemmon 200k?  Hmmmmm,  perhaps I haven't been as much out of shape as I thought?

In other news, after midnight, there was an unusual amount of four wheelin Jimmy Bobs and their long necks  coming back from a long day of buzzing through the desert on their various machines of choice.   One car whizzed by me at what had to be 80 mph or more  as they honked.   I kept an eye out for their dead carcass when I descended the other side of the pass but lady luck must have been with them.    Despite all the bozos and boozos it was a beautiful night and with the full moon shining, the lights got turned off on the climbs (not the taillights of course).   It was just me,  the moon,  the road,  and innumerable silhouettes of Saguaro Cacti,  Mesquite, and Ironwood trees.   More than once I could hear Coyotes wailing at the moon just off the road.   It was a  good night and I was glad to have been out and enjoyed it despite the high idiot count.

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