Kestel has been on the triathlon seen for many many years already and you may find it odd to see something missing from this bike. No we did not photoshop the seat tube out but this is the signature design from Kestrel. This brand defiently has been building a brand for itself especially with triathletes such as Andy Potts and Cameron Dye riding for them. The Kestrel Airfoil Pro SL may not be as stiff as some other bikes out there especially when it comes to climbing hills but in the aero position you can see how one less seat tube would reduce drag. Theres’s also a unique smootheness in this bike that comes from the reduce vibrations from the seat as the seat tube is not existent. What we like about this bike is that it’s in an affordable range.