Self fit tools and process

Since I’ve spent the $ to finally get a good bike, actually a great bike a P2k. I’ve gone through a pretty extensive self-fit process. Note, the self-fit is almost mandatory as I can’t find anyone nearby that I trust to do the fit; although I may have a lead with John Cobbs Bike Sport in Tyler TX - I just can’t find anyone who has ever gone to them for a fitting.

Anyway, here is the process I used. I would love to get some constructive comments. Also I have a couple of questions. Setup bike on trainer and insure that top tube is level. (Top tube is level when the bike is on the ground) Set saddle to 78* and used already established saddle height. Calculated appropriate drop and set bar to that height. Set middle of aerobar pads to 8.5" apart as a starting place. (8.5" was the distance on my old bike) Set up a tripod and digital camera about 8’ away. Get on bike an pedal for a few minutes to insure that I am sitting on the saddle exactly where I sit while riding. Take picture on bike with pedal spindle in line with seat post. I brought the digital picture into Microsoft Paint and drew a red line from elbow to shoulder to hip joint to pedal spindle using the instructions from Dan’s fit page. Using the lines drawn in Paint, look for the 90* angles. Adjust fit as needed and repeat steps 5-7 until both angles are 90* and upper part of back is horizontal.

I used a small piece of a sticky note on my hip joint so that it could be seen on the digital picture.

Questions: How to I improve the process? Where is the collarbone bony protusion that Dan talks about? Drawing lines in Paint is very useful, critical in fact to my untrained eye. However, it would be nice to use some sort of CAD program to make exact 90* angles. Currently using paint I connect the dots and then eyeball the position until the lines look like 90*. Does anyone know of a free or cheap program that I can import a bmp or jpeg and then either draw and rotate a box or make exact 90* angles on the picture? Does it matter how far apart my hands are? Does it matter if I move the bars in very close to the stem while keeping the pads so that they mask my thighs? I want to mount my profile aerodrink, but this means either creating/buying a mount system or moving the bars very close together. I think I would be comfortable with my hands almost touching and elbows/upper arms set to mask my thighs, but I’m not sure if it will make much aero difference.

The leveling should be between the your front and rear axles… this negates any slope to the top tube…

this process would be infinately easier with an assistant…

Also helpful would be a full length mirror that you can look at yourself from the sides and the front… dynamic movement is as important as the static.

The assistant would be able to help you mroe accurately take your measurements as well…

improving the computer portion would be greatly aided by putting markers on your body,as to the location of yout landmarks…

For the computer thing… if you have the landmarks marked already you can take a regular right angle T square and put it up against the screen

photographs… as anyone can tell you proper positioning of the camera is of the utmost importance for accuracy. Make sure it is dead level in all directions.

If you can get an assistant, it will be so much faster. My wife, baby on her hip, is sometimes called out to the garage as I’m tinkering with position. I have a mirror, but that’s not the same as having an observer…she’s even gotten to the point where she tells me, “Don’t look to the side, it changes your shape, I know what line you’re asking me to look at!” I use adhesive dots to mark body points, string and/or light elastic bands, and a BIG carpenter’s right angle tool…the bigger the better. She’s gotten confident enough that she can tell me when I’m off more than a couple of degrees. She’s gotten to the place where she can walk by and comment on my positioning (your back isn’t as flat as usual, you look very comfortable/crunched/reaching too far, etc.) It also helps to show her a picture of someone with the same basic back shape that I have and tell her I want to get in that position, or a little lower in front, etc.

Since you’ve done the basic setup already, using someone to fine-tune shouldn’t take up too much of their time. They don’t even have to know about bike fit, as long as they are very observant and meticulous in looking for what you need to know.

To answer one of your other questions, yes, it probably does make a difference how wide your hands are compared to your elbows. Guessing what difference it would make is taking a shot in the dark, though! In light of having no wind tunnel, go with the position you feel most comfortable while still being able to generate good power. For example, I used to like my hands closer to my body, but, I’ve begun pulling up on the aerobars this year especially on shorter hills…so I like my hands a little more ahead of me than before…I think I get more leverage this way, and it’s comfortable. It also allows me the ability to ride on the rivet for a while, without being too crunched up. And since I have the curved C2’s, I can slide back on the seat, change hand position, and still be appropriately positioned and comfortable. Just try different positions with your hands narrower, wider, etc., and see what you like the best…that will probably get you to the line faster. However, if it is a short race, you might do better to be in a position which isn’t very comfortable (very low in front, very narrow body positions, etc.).

Ok at risk of sounding…blunt. It sounds like you have done a great job. Is your new pos comfortable? Do you like the aggressive pos? If the answer is yes to both or either of these questions, then forget dealing with anything else. Get out and ride. Test the real world effects. Good luck.

Shawn

I used the aggressive drop that I was worried about, and all the other results of the best self-fit I could get. I had my first long brick on the new bike this weekend. I was out of town and had a hilly course with some sections of fairly rough road. I set my PR for a 60 mile ride. It was simply amazing. I do have some neck soreness from looking up, but that will go away in a few more rides. Everything else is wonderful - the most comfortable that I’ve ever been on a bike.

Thanks for the help.