Please help! I have a client who wants to use my fit data to purchase a new tri bike. I have been using the fantastic calculators on this website but I am not sure if I am doing it correctly so want you FIST guys or girls to verify or correct my error(s) before I get back to my client.
I performed a retro fit on a Trek 1200 56cm 2004 road bike with Profile Design T2 Wing 42cm base-bar and Profile Design T3+ Carbon aero-bar with 15mm of riser.
Serotta XY co-ordinates: 448/630 (X/Y)
Head tube angle 73°
Stem length: 70mm
Stem angle: +6°
Stem Clamp height: 40mm
Spacer Height: 30mm
Headset topcap: 10mm (this is an estimate as forgot to take the measurement: external bearing headset was in use)
Effective seat tube angle: 73.7°
Now using the F.I.S.T Bar to Head Tube Calculator I get a Stack and Reach of 545/401
I then understand that as the effective seat tube angle is shallower than on a tri bike and therefore the reach needs to be extended to compensate:
I calculate this to be adding an additional 22mm for a 76° STA to make Stack and Reach of 545/423 - - Is this correct?
(calculation using ST 560mm. I have also used the shallower of the typical tri STA on the basis it is cheaper to buy a longer stem than a new bike)
Using the Stack and Reach Database I am getting a close sizing for:
Trek SC in Large (541/426)
Dimond in Medium (540/425)
Cervelo P3 or P5 56cm (540/425)
Cannondale Slice 57cm (547/420)
Are these the bikes I should be recommending or am I overlooking any factors that will influence the right bike such as the stem length used on the stock bike etc? My understanding is Stack and Reach means that I can ignore these other parameters.
Again your help in this matter would be very much appreciated.
PS: And yes I know I should do the FIST course but can't afford it at the moment.
Serotta Advanced and Advanced Triathlon
Retul Certified in 2011
Qualified sports massage therapists