Tuesday, October 31, 2006

Bike Fit

So I have been playing around with my bike fit lately. I have a Trek 1220 from 1994. I have never really been that comfortable on it. I used to think that it was an issue of conditioning, but am learning that it just doesn't fit right.

When I bought my Trek I really knew nothing about bikes. I had two bikes as a child. The first on was a small single gear bike with a banana seat. I always felt pretty stupid in that bike because my older brother had a cool BMX bike, while mine had an embarrassing banana seat. Not only that, but it has these weird handlebars that consisted of an L shaped metal tube that fit into a bracket attached to the front fork. They would constantly get loose. I even crashed a few times because they would come off. My second bike was alot better. It was a french steel racing bike with 12 gears I think. I think it may have even had campy components too. In any case the top tube was too high, and I would hit myself in the crotch during dismount rather frequently. I also stored the bike outside (stupid kid) and so the bike would get rusty and the derailleurs were always out of alignment. It would cause me to drop the chain regularly. So my experience with bikes has not been good.

But back in 1996 when I was looking to do my first triathlon I picked up an issue of Triathlete magazine (I think it was April) and in the back it had an article on converting a road bike to a tri-bike by adding a new seat post and aero bars. I think the bike in the article was a Trek 1200 or 1220. I wish I still had that article. Anyways, I didn't have much money so I looked for a used road bike and came across an ad for a Trek 1220. I think it was the first bike I looked at. The fact that it was very similar to the bike in the Triathlete Magazine article influenced me and of course I was very interested. The owner lived in a trailer park and was incredibly thin. I suspected (but didn't ask) that he had some kind of disease and that was why he was selling his bike. The bike was relatively new and in great condition. The first thing I checked was the clearance between my legs, and I had a few inches. So it fit! I paid the man and road off in my new bike quite proud of myself.

But of course now I know better. After having it a while I first noticed that I couldn't get the seat high enough. No problem. I wanted to buy a new triathlon specific seat post anyways. I would just get a longer one. I found a nice Nitto 66 seat post and that is what I have been using all these years, but I now think that even it is too short. (In the photo below I think I have the height about right, but it is raised above the maximum level marked on the post.)

Part of the problem is that I have freakishly short legs. I am six feet tall, but only wear a 30 inch pant inseam. Normally a person my height would ride a 56cm or 58cm frame, but I measured my bike (seat tube center to center) and now know it is 50cm. Because on road bikes the top tube and the seat tube are proportional I have a really short top tube even though I have a relatively long torso. Fortunately on the smaller frames the Trek 1220's have proportionaly longer top tubes. Mine is 53cm, but it should probably be around 56cm or 58cm for a bike that fits me.

I put on some Profile Design aero bars, but as I have mentioned many times in this blog, I cannot hold an aero position for more than a few minutes. When I am in the aero bars I feel really compressed.

The pink line shows where I currently am. I moved the seat forward so I would not feel so compressed. But now the angle between my legs and torso is a little open. It should be around 90 degrees. Also the angle between my upper arm and torso is too tight. It also should be around 90 degrees. To get the proper position I think I should be where the green line is. That puts me quite a bit in front of the handlebars. I could put on a longer stem to extend the handle bars out farther, but not that far. The bike would have much too much weight over the front and the steering would be very unstable. I think I may be able to compromise with the position represented by the blue line. I would have to get a new stem and lower my handle bars, but it looks doable.

The other option is to just scratch the whole thing and try to get it back to a road bike position. I am not in a financial position to replace the bike right now, but I probably could get a more comfortable road position by getting a new seat post. Then I could just train in road position until I can eventually afford another bike, hopefully a tri-bike. Decisions, decisions.

If anyone has any ideas. . . now is the time.



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