Black Mamba Intro and Best Bang for Your Aero Buck

Couple of items for discussion today.  I’ve got pics of the new tri chariot in its race-ready glory.  Sweet I must add.  Much easier to stare at the bike than go to a 3 hour tempo ride.  It will be a fast bike and a wind cheater.  I’m still fine-tuning the fit after getting my general position fit at Bicycle Cove with Chris L.

Welcome to the Black Mamba:

Technicals:

  • Size Large Trek Speed Concept 9.9 Project One build
  • Frame: 600 Series OCLV
  • Wheels: Zipp 808 FC Carbon clinchers; Tires: Continental 4000S (700 x 23c)
  • Drivetrain:  SRAM Red with R2C Shifters and Quarq SRAM Red Powermeter (53/39)
  • Brakes: Bontrager Speed Concept integrated brakes w/ Bontrager Race XXX Lite aero levers, integrated cable adjuster
  • Saddle: ISM Adamo Time Trial
  • Pedals: Shimano Ultegra
  • Aerobars: Bontrager Speed Concept carbon basebar with carbon extensions
  • Extras: Draft Box; Arudel cage with aerobottle on seattube.

It is a very aerodynamic frame.  I love the integration of all the cable housing.  The only cables you see are a few inches that drop down from the aerobars to the frame and a short loop at the rear derailleur.

This is what the wind sees..not much.  Sadly, most of the aerodynamic drag is me sitting on the saddle…damn zebra cakes.  The Speed Concept departs from the super deep downtubes popular with other brands.  Trek calls their aerodynamic tube design: Kammtail-Virtual Foil (KVF).  Essentially they cut the end off the airfoil.

The wind is none the wiser.  Trek claims this causes the least air resistance making the frame the “fastest on the planet”.  But you know they all say that.  The front brake and the rear brake are integrated into the frame for the lowest possible drag also.

Here’s pic of the cockpit.  The basebar has some forward shift which can put the brake levers farther away but I like the flat hand rests.  The extensions and armrests are very adjustable…fore-aft, up-down, and as I’ve done here, tilt of the bars inward at the shifters.  I’ll probably mount a horizontal bottle cage between the aerobars and my bike computer will go in front.  Still tinkering with those positions.  Comfort in the aerobars is very important.  May need to hunt up some CeeGees pads too.  These stock ones are firm.

Another little bonus with these aero brake levers is the cable adjuster at the end.  It allows quick movement of the brake pads for different wheel widths.  Not enough for the wide Firecrest, but I’m still playing around with that.

The bottom bracket is BB90.  It’s much more stiff and responsive compared to the Bumblebee.  Coming around a curve, I can pound on the pedals and the bike is very responsive.  I may switch my aerobottle setup on the seat-tube for the Bontrager Speed Bottle.  It fits in that bottom triangle better and would provide a little less drag.

 

A nice little bonus is Trek’s draft box.  It fits seamlessly behind seat-tube and stores my flat kit at this time.  I also zip-tied a bottle cage under the seat.  It’ll hold another water bottle on my long rides.

One last goodie: If you so choose, you can wireless put Trek’s duotrap sensor into the frame to record all speed, cadence, etc.  No big bike sensor sticking up on the rear chainstay.  Are you seeing the trend here?  It’s all about reduced drag and free speed.  I’m all for free speed.

But as nice as that bike frame is, it is worse bang for your aero buck.  It’s not all bad news.  I used a cool resource to compare the time and power saved over a 40K course between the Bumblebee and the new ride.  Check it out here:  http://www.cyclingpowermodels.com/ComponentAerodynamics.aspx

That source reports the new frame running a disc in the back will save me a minute over a 40k course.  Over an Ironman course…not too shabby.  Ok that’s one end of the spectrum.  Buying an expensive time-trial frame will make you faster, especially compared to a stock road bike without aerobars.  However, buying a $200 aerohelmet will save you about a minute over 40K also.  That’s an affordable $3 per second saved.  That cool frame is closer to $100+ per second saved.  You do the math.  That super-cool deep section wheelset?  That may give you 1-3 mins over 40K  for a $10-70 saving per second.  Newer studies suggest a well-fitted aerohelmet reduces drag better than some wheelsets.  I assume most triathletes have at least clip-on aerobars.  Those suckers are golden, saving 2 mins over a 40k course, and dropping the dollar sign to $1.50 per second saved.

Though I chose to go with the mid-life crisis superbike, the average triathlete can balance speed and cost.  Got a couple more races this season.  I’ll let you know if I pass Chris Lieto in any races…uhh…not.

Thank for reading,

Doc

 

 

2 Comments

Filed under Triathlon

2 responses to “Black Mamba Intro and Best Bang for Your Aero Buck

  1. “mid-life crisis superbike”. That’s funny. The first step toward recovery is admitting you have a problem.

  2. Dave Truitt

    Suh-weeeet! Man, that machine is beautiful. Thanks, for the reality check on the costs per time saved. Looks like I’ll be buying an aero helmet before Goosepond Island Half.

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