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Friday, January 30, 2009

Bike Fit

I've been working on finding the "right" position on my bike, especially in the aero bars.

What is the "right" position?

Ultimately the right position is the one that enables you to generate the best possible results while still being comfortable for the hours and hours you'll spend on the bike.
I used this article as a guide.

The main keys are the hip and shoulder angles, both should be 90 degrees. I had my wife take a picture of me on my bike, then I figured out what my angles were.

The first picture, with the lines drawn in:

Pretty close actually. As you can see, though, my shoulder angle is too acute (less than 90 degrees) and my hip angle too obtuse (greater than 90).

I still had spacers on my headset, so I removed all of them and dropped the handlebars down as far as they will go.

This is the final set-up I came up with, it pretty closely matches the angles from the article.

I also measured my knee angle to make sure my saddle was the right height, it seems OK. The only thing is that I'm not sure while I'm pedaling if my heal is dropping down, which would over-extend my leg. It feels comfortable, but I may take some video to analyze my pedal stroke in a bit more detail.

Any comments/feedback is appreciated!


After I posted this blog entry, I received some advice from the good people at Trifuel.
  1. Seat too high - my knee is too extended in this position, I need to drop the seat a little
  2. Flip the stem - I should be able to go lower and get that hip-to-back angle to 90 degrees by flipping the stem
I made these updates, the result is:

I'm really happy with the position - you can see how flat my back is compared to where I started! I had a two hour spin class today on this bike/trainer combo, and it was completely comfortable. Dropping the seat also really helped my pedaling, I felt much more power at the bottom of my stroke as I could get my heel down properly.

Thanks again to the folks at trifuel - great feedback. :)


cdnhollywood said...

In theory, it looks pretty good. I had this done after the purchase of my new bike, and it felt horrible for a while. If you have the same feelings, just stick with it for a while 'cause you'll build up the strength and endurance where you need it.

And you'll QUICKLY find whether or not that saddle will work for you in this position. :D

Aaron said...

I'm by no means an expert, but here's my bit (it's free, so you get what you pay for). Aero is one thing. Comfort is another entirely. You can be the aerobeast of the day, but if you can't hold the position for the majority of the ride, it's not helping you. You'll need to give it a couple hundred km to test it out. For a new position, expect a little discomfort in the back in the beginning, but that should go away.

Karisma said...

I have been reading your posts regularly. I need to say that you are doing a fantastic job. Please keep up the great work.

Abigail said...

Good work on this post! I really like the way you delivered your qualitative facts and how you made this fascinating and effortless to realize. Thank you!!

Truman Benson said...

I think the first one is better than others. One of my bike consultants advised me to apply for that position when I ride on my bike, he also called me to avoid other position because those are hamper for our body.