An ICA member asked about using the arm to determine the distance between the seat and the handlebars:
I turned to Tom Scotto for the answer to this question. We will have much more shortly on proper set-up on the bike, but this is a quick and easy way to set up the handlebars if you have handlebars with a sliding fore-aft. Keep in mind that this is not how you determine the position of the saddle - that should be set up so that the knee is lined up directly over the pedal spindle. (More on that soon!)
How should I measure or determine my handlebar fore-aft position? This question is being asked a lot these days as more and more bikes on the indoor cycling scene have the ability to make this fore-aft handlebar adjustment. As usual, the answer always is, "it depends." It depends on a number of issues such as flexibility, injuries, mobility, alignment and strength. However, in order to give you some guidance and a starting point, let's assume all is good without getting tangled in navigating each issue.
We've analyzed over 200 bike fits done at our performance lab and have found the following to be a good starting point for most riders. First, let's assume we are going to consider our indoor bike a "road bike". This is an important assumption to agree on since bike fits and geometry varies greatly with mountain bikes and triathlon bikes for example.
With the rider on the bike, have them bring their foot/pedal to 12 o'clock. Place the bone of the elbow on the bone of the knee (patella). Adjust the fore-aft position of the handlebars until it intersects the rider's wrist. That's it. Very simple and closely mapped to how this is performed during a biomechanics session. Of course, this is just a neutral starting point. More flexible and aggressive riders may prefer the handlebars a bit more forward and others may prefer a more upright position for comfort (or due to some of the issues listed above).
Remember, there is an optimum position for ideal form, efficiency and power production, but the only true optimum position is one that takes the rider's needs and abilities into consideration.