To aero or not to aero….

First things first…. my baby bro informed me that I should have posted a pic of my calves if I was going to talk about them, so…..

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Now, on to business. Midway through today’s swim I started to think about the weather… staring at a black line for any period of time makes me do this. Today’s weather made me think that shaving my legs did a lot better job of bringing spring around than that stupid groundhog, and I figured that I should reward myself. So I wrapped up my swim a little early, did a little ride to try to get used to the aerobars on my bike and then, since I still had a little time, I thought I’d do a run. So I did my own little (and distinctly unconventional in terms of distance) triathlon. Did 2200 yards in the pool in 44 minutes, 8 miles on the bike in 22:30 and 5.15 miles on the gams in 45:00.

The aerobar thing was the rub, though. Aerobars are extensions you put on your handlebars that allow you to bring your arms and shoulders in in order to present the smallest possible profile to the wind. According to Matt Fitzgerald (in The Complete Triathlon Book, 2003) aerobars can knock 3:24 to 4:36 minutes off your 40k bike time in an olympic tri. Unfortunately, what you gain in speed you give up in bike handling and stability, especially if you’re using clip-on aerobars on a road-configured bike, as I am.

Bikes that are designed for triathlon have a geometry that brings the person forward with respect to the front wheel. The seat tube angle (the seat tube is the tube that runs from the bottom bracket, where the pedals attach, to the seat) is far closer to perpendicular than a road-configured bike is, which pushes the person forward. The seat tube on a tri bike is angled only 12° from straight up, where in a road bike that angle is usually around 16-19°. They also use a smaller wheel base, so often, in carbon tri bikes the seat tubes is molded around the wheel. So their design allows for more comfort and more stability with a forward aero position. Unfortunately, that kind of bike is out of my budget, and realistically is not something I’m interested in getting. Tri bikes are good for one thing, and if I’m going to sink a lot of money into a new bike I’d rather by a better road machine for racing than a tri bike (remember, I’m a cyclist who does triathlons…. you know….. cycle snob).

So what do you do to turn a road bike into a tri bike? Here’s Holly the Raleigh in her happy road configuration (except for my race wheels, which still have the trainer tire on them):

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To turn her into a tri-specific configuration, I have to move the seat forward to mimic a seat tube with a higher angle. This requires changing out the seat post from a set-back model to either a post with no set-back or one that’s set forward. I also have to shorten the stem for better position and add aerobars, like so:

 

 

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Unfortunately, there’s nothing I can do with the wheelbase, and having my hands so far in front of the steering axis makes the bike very jittery. In addition, to get proper aero position I have to rotate my hips on the saddle, which needs to be tipped forward a little, and hunch myself over the aerobars. Considering the hours I’ve spent so far this year training in a road configuration this new way of sitting on the bike is not terribly comfy, and my confidence on the bike is completely out the window. In addition I’m going to spending a LOT of time on the bike this year in road configuration doing brevets. I guess I’m going to have to think about it. Right now, to keep from thinking too much, I’ve changed Holly back.

Oh, well, if all else fails I’ll slap the aerobars on The Beast to give me another hand position for randonneuring!

 

 

 

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2 Responses to To aero or not to aero….

  1. vardotrichic says:

    You could possibly borrow a tri bike from the shop if they have one in your size…then you wouldn’t have to venture out of your budget 🙂

  2. RoRo says:

    Is that the visible version of that invisible bike that cat is always riding?

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