Analysis of Austro-Daimler A-D TT geometry

Frame and Wheel reviews the geometries of the four sizes available for the Austro-Daimler A-D TT frame. Frame and Wheel estimates the reach from the schematic drawings of the frame

Austro-Daimler A-D TT geometry analysis

Cm	50	52	54	57
Seat tube (C - T)	50.0	52.0	54.0	57.0
Top tube (effective)	53.5	55.6	57.7	58.7
Head tube	9.0	10.5	12.0	14.0
Chain stay	37.6	37.6	37.6	37.6
Front center	57.5	59.6	61.7	62.9
Wheelbase	94.0	96.1	98.2	99.5
Head tube angle ⁰	73.3	73.3	73.3	73.3
Seat tube angle ⁰	74.4 / 77.2	74.4 / 77.2	74.5 / 77.2	74.5 / 77.2
Bottom bracket drop	7.0	7.0	7.0	7.0
Stack	47.8	49.7	51.7	54.5
Reach *	40.3	41.0	43.0	43.6
Fork rake	4.4	4.4	4.4	4.4

 * Frame and Wheel estimates

The seat post can be adjusted to obtain two seat tube angles. The forward position of the seat post results in a seat tube angle of 77.2 degrees. Generally, this puts the rider further forward onto the handlebars and into a more aerodynamic position. It is suitable for standard or short time trials. The rear position of the seat post results in a seat tube angle of 74.4 degrees. This is closer to the traditional geometry of most road bikes and places more of the riders weight on on the rear wheel. It is less aerodynamic, but more comfortable and suitable for triathlons. The head tube angle on the 50 cm is 73.3 degrees. This is pretty close to the middle of the head tube angle range (71 to 75 degrees) and comparable to the head tube angle of standard road bikes. This suggests that the ride will be stable and smooth, particularly at high speeds. Elsewhere on the 50cm, the wheelbase is 94 cm, the stack is 47.8 cm and the reach is 40.3 cm.