Y'all should read what PJW has to say on bike fitting: http://www.peterwhitecycles.com/fitting.htm
Quoting at nauseous length: "The Fore-Aft Saddle Position Now we get to what I think is the most important part of fitting a bicycle, the fore-aft position of the saddle. Once you get this right, everything else is easy. This position is determined more by how you intend to use your bike than by anything else. If you look at a typical bike, the saddle is behind the crank center, or bottom bracket. There's a frame tube (the seat tube) running from the cranks to the saddle, and it's at an angle. That angle partly determines the fore-aft position of the saddle relative to the cranks and pedals. That fore-aft position determines how your body is balanced on the bicycle. Your balance determines how comfortable you are, and how efficiently you can pedal the bike. Stand up straight in front of a mirror and turn to the side. Look at yourself in the mirror. When standing straight your head, hands, seat and feet are all fairly close to being in line with each other. Now bend over at the waist. Notice that not only has your head moved to a position ahead of your feet, but your rear end has moved behind your feet. If this were not the case, you would fall forward. Your seat moves back when you bend at the waist to keep you in balance. Your torso needs to be leaning forward for two reasons; power output and aerodynamics. With an upright torso, you can't use the gluteus muscles to good effect. Also, you can't effectively pull up on the handlebar from an upright position. An upright torso is also very poor aerodynamically. When cycling on level ground, the majority of your effort goes against wind resistance. The easier it is for your body to move through the air, the less work you'll have to do. With your torso closer to horizontal, you present less frontal surface to the air and don't have to work as hard to maintain a given speed. Obviously, the most aerodynamically efficient position may not be the most pleasant position to be in for several hours on a cross country tour. So there's a tradeoff. As you move to a more horizontal position, the saddle needs to be positioned further to the rear to maintain your body's balance, just as your rear end moves to the rear as you bend over while standing. It so happens that racers are more inclined to use a horizontal torso position than tourers, and racers are more concerned with having the handlebars further forward to make climbing and sprinting out of the saddle more effective. If a bicycle had the saddle directly over the cranks, you wouldn't be able to lean your body forward without supporting the weight of your torso with your arms. Because the saddle on a typical bicycle is behind the cranks, your seat is positioned behind your feet and your body can be in balance. Try this test. You'll need a friend to hold the bike up, or set it on a wind trainer. Sit on your bike with your hands on the handlebars and the crank arms horizontal. If you have a drop bar, hold the bar out on the brake hoods. Try taking your hands off the bar without moving your torso. If it's a strain to hold your torso in that same position, that's an indication of the work your arms are doing to hold you up. For starters, I like to put the saddle in the forward most position that allows the rider to lift his hands off of the handlebar and maintain the torso position without strain. You should not feel like you're about to fall forward when you lift off the handlebar. If it makes no difference to your back muscles whether you have your hands on the bars or not, you know that you aren't using your arms to support your upper body. If you are, your arms and shoulders will surely get tired on a long ride. But this is a starting position. Remember that bicycle fit is a series of compromises. So what's being compromised? Power. There's a limit to how far you can comfortably reach to the handlebar while seated. If the saddle is well back for balance, the handlebars will need to be back as well. But to get power to the pedals while out of the saddle, it helps to have the handlebars well forward of the cranks. Particularly when climbing out of the saddle, the best position tends to be had with a long forward reach to the bars. You can tell this is so by climbing a hill out of the saddle with your hands as far forward on the brake lever tops as you can hold them, then climbing the same hill with your hands as far to the rear as you can on the bars. Chances are you can climb faster with your hands further forward. So you need to find the best compromise between a comfortable seated position and reach to the handlebar, and a forward handlebar position for those times when you need to stand. Only an inch or two in handlebar placement fore-aft can make a big difference while climbing. That same inch or two in saddle position can mean the difference between a comfortable 50 mile ride and a stiff neck and sore shoulders! As you move the saddle forward from that balanced position, you'll have more and more weight supported by your arms, but you'll be able to position the handlebars further forward for more power. The track sprinter has the frame built with a rather steep seat tube angle, which positions the saddle further forward from where the tourer would want it. But again, the track sprinter spends very little time in the saddle. If you can't move your saddle forward enough or backward enough for the fit you want, don't despair. Different saddles position the rails further ahead than others, giving more or less saddle offset. Seatposts are available with the clamps in different positions relative to the centerline of the post. So, how do YOU want to balance on YOUR bike? Do you want to emphasize speed and acceleration? Do you care mostly about comfort and enjoying the scenery? The answers to these questions determine how you position the saddle, not some computer program or someone's system of charts and graphs. How your best friend fits his bike should have no bearing on what you do even if he has exactly the same body proportions as you. YOU know why you ride a bike. Only YOU know what compromises you are willing to make in order to achieve your purposes on a bicycle. You may have a bicycle for short fast rides, and another for long tours. Just as the two bikes will have different components so as to be well suited for their purposes, so might the fit be different. The rider hasn't changed. You are still you. But your purpose has changed. The light, fast bike for short rides will likely have a more forward and lower handlebar position than the tourer. And so the saddle may well be further forward too. As you move the saddle forward or rearward, you are also changing the effective saddle height, relative to the cranks, since the saddle rails are usually not perpendicular to the seat tube. So be prepared to change the seat post extension as you adjust the fore-aft saddle position; lowering the saddle as you move it back to maintain the same leg extension, and raising it as you move the saddle forward." -- Patrick Moore Albuquerque, NM For professional resumes, contact Patrick Moore, ACRW at resumespecialt...@gmail.com (505) 227-0523--
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