Monday, July 20, 2009

Drafting 101

Drafting is fun. No, I don't mean the practice/profession of designing mechanical and architectural structures with mechanical pencils or Autocad, I mean following a vehicle close enough to tuck in its draft and get pulled along at speeds not normally attained on flat roads on a bicycle. I usually take advantage of opportunities to hop in behind a truck or a bus, even on a recovery ride, just because it's fun.
So, today I left work with the intent of doing a 20ish mile ride, low tempo, keep it at the low end of zone three. The first ten miles went according to plan, then I saw it, one of those commuter buses dropping off a couple of passengers. It just started to accelerate as I got in behind it, but accelerated very quickly, up a slight hill, I managed to stay with it for about 1/4 mile,but he kept accelerating, I lost him.

I rode along for another few miles until georgetown center, where I saw a semitrailer pulling out onto 97 north, the same route I had planned on. I hopped on and soon we were pushing 40, a little delay for a car turning in front of the truck then back past 40...42!
Bummer, the truck turned off at center street.
A couple of miles later, I was approaching the groveland bridge in haverhill. Traffic generally congests here, with the jct of 113 and the single lane bridge passing a large shopping plaza across the merrimac river. I hopped in behind a minivan. It slowed for traffic after the bridge, but then picked up over 30. Damn, it turned off after 1/4 mile.
A mile later, a box truck pulled out of a store close enough for me to bridge up to it. I stayed with it for 1/4 mile until it too turned off.


Last year I caught a truck draft from georgetown to the groveland bridge, about 4 miles, keeping it about 40 the entire way.

Drafting is actually a tried and true training tool, though it's usually done with the knowledge and cooperation of the driver, and usually small vehicle like a moped. That said, I'm not sure hopping in truck drafts really nets any benefit, but it sure is fun.


gewilli said...


zencycle said...

hmmm, Must have fumble fingered something. The jpg is at home, I'll fix it tonight.

Amanda said...

I've always just wanted to grab the bumper of a passing truck...weeee!