Dan, I'll give this one a shot, as a chance to paraphrase some concepts I learned in your FIST clinic.
As a bike fitter, you begin with the assumption that the rider is a triathlete and therefore wants to be in the "optimal" tri position. We tossed around a lot of words until we settled on optimal.
Optimal Tri Position
- 78 degree seat tube angle
- 90 degree angles formed by torso and leg (hip angle), upper arm and torso, and by the elbows.
- Aerobar tilt is largely a function of rider personality. A aggressive rider, such as Jurgen, might want the bars tilted downward, as they feel they use the bars to get better leverage. A more relaxed rider (Dan calls it "whispering louder") will want the aerobars level or even tilted up.
- You then adjust the drop between the seat and elbow pads to the rider's comfort, while shifting the seat fore and aft to retain the 90 degree hip angle.
You begin with these assumptions and then, by qualifying the subject, you either retain the optimal tri position or work backwards along the spectrum of bike fit: from optimal tri position (most aggressive) to "multisport position" (less aggressive) to road or "slam" position. During this qualification process you assess the subject for flexibility, "thinness," what they want to get out of the sport, what they want to do with their bike, etc.
Three examples:
- Kona AG qualifier: very fit, athletic with aggressive goals. This person would be best served on a tri-bike (78+ seat tube) in an optimal tri position.
- MOP'er, wants to race tri's but also ride in the local road races. Maybe carrying a little extra around the middle. Probably best served with a multisport bike in a multisport position, allowing him to participate on multiple roles.
- 65 year old woman carrying a few extra pounds. Not very flexible or comfortable in an aggressive riding position. Would probably be best served on a road bike with a slack seat tube angle and shorty aerobars, like Jammer GT's.
Your desired endstate is an athlete with a bike and fit combination that fits their body (it's capabilities and limitations), personality, and goals in the sport. What is critical here is that where an athlete winds up on this continuum is entirely fine. It's all good. However, the athlete must be educated about what his best and appropriate fit is, given the limitations of body and equipment.
I think what Dan is saying that the bike companies assume that these athletes are not athletic enough to assume an optimal tri position on a triathlon bike (78 seat tube, short top tube). They then sell road bikes (defined by seat tube angle and top tube length, basically) as tri-bikes, in an effort to jump on the triathlon wagon. Athletes then buy these bikes and try to assume a tri-position which is sub-optimal by definition.
A perfect example is my girlfriend, who purchased a road bike at Supergo before we met, then got fitted on it by some clown who tried to turn it into a "tri-bike." Our first ride together after the FIST clinic I recognized her position as a complete abortion. I'm now looking at how to achieve her best position within the capabilities and limitations of her seat tube angle and top tube length. A better solution would be to buy her a tri geometry bike, but that is not in the cards right now.
Rich Strauss
Endurance Nation Ironman 2013 and 2014 World Champion TriClub, Div I
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