Comparing Online Fit With Professional Fit

**I am NOT a bike fitter and have ZERO training in bike fitting, but I have been fit for a tri and a roadie by a fit guru, and paid attention...  ...still please take this advice/info with a healthy shake of salt!***

I'm 187cm tall, or just under 6'-2". I ride a moderate amount (>800 miles so far this year). I a 19.1 MPH racer on a flat Oly course like Nation's Triathlon in downtown DC, riding on a road bike (No tri bike yet ... gonna build one this winter... but that is another post!) I am a HUGE advocate of professional fitting ... it is the most important $100 upgrade you can get for your bike, in my opinion. And, with a pro fit, the pro will also set your bike up for you.... as usual, anybody can have a plan, but execution is the differentiator!

I was professionally fit recently, and compared the results with the results from the Competitive Cyclist tri-specific fit program on their website just now. Pretty darn close. For instance, I was fit to a 32" distance from crank bolt to seat top on a tri bike, and Competitive Cyclist was 32.3". (My road bike fit was 32.5", but this feels just a little long for me, so I've settled on 32.3" for my roadie seat position, BTW). For tri bike size, I was fit to 560mm ETT with 110mm stem, and Competitive Cyclist calculated 559mm - 579mm, with an 80mm to 100mm stem ie pro fit was 670mm total and Competitive Cyclist ranged around 660mm +/- 20mm.

There were some differences to, because of my own personal body geometry. That plus-minus 20mm above is 40mm total ... almost 2 inches ... pretty big gap (but within the range of most stem length adjustments) Also, I have relatively low hip mobility .... about 120 degrees of hip flexion. I have a stiff sore neck with limited neck mobility, and so neck pain and heads-up visibility is a big concern for me on a tri bike. So for seat to to arm rest drop, my professional tri fit was 8.9 mm (3.5" inches) and Competitive Cyclist was 9.1mm or 3.6" for their "minimal" aero tuck, 14.8mm (for moderate), and 17.3mm (for intense) and 21.4 (maximum). It is interesting to see that I'd was fit right into the Competitive Cyclist minimal position, given the neck mobility problems I have, but if the moderate position would be too steep for comfort for me.

Also, I think the on of the MOST important dimensions on fit comes from the X-Y position of the handlebar-stem center point relative to the center of the crank. My X-Y was 73mm in Y (straight up from the crank bolt to the level height of the stem-handlebar joint) and 48mm in X (straight across form the crank bolt to the stem-handlebar joint). This is more important than ETT and stem length, because of the differences in stems, frames, etc ....

There are a lot of other benefits from a pro fitting ... for instance, good cleat alignment on your shoes. Imagine the problems that a bow-legged rider could have with cleats set up directly straight ... this is somewhat of an exaggeration, but you get the picture.

Taylor B provided the link to the Competitive Cyclist fit calculator in an earlier post on the subject:
http://www.competitivecyclist.com/za/CCY?PAGE=FIT_CALCULATOR_INTRO&INTRO_LINK=NOREDIR&SITE.CODE=TRI

Jeez, this was a long post to prep and write. I'm gonna go ride! Whoooooohooooo.

PS-If you need a recommendation on a great fitter in central Maryland, Tom R. and the Bicycle Escape in Frederick is wicked good at this stuff.