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How to choose Stem length?(4 posts)

How to choose Stem length?Fkp4ever
Jan 31, 2003 11:57 AM
I'm building up my road bike and need to know how to select the proper stem length. My team is sponsored by Ritchey so I'm going to be getting WCS bar and stem and could use some help in telling what sizes to purchase?

My frame is a 54,
Height: 5'9", weight: 145.
Average arm length (not orangutan like).

I was guessing something like 110mm??? but I have NO CLUE what so ever. Wish I could try it out first, but all I can do is order it and see if it fits.

Thanks in advance for any replies,
If you can, order the bike without the stem. Then, when it'sbill
Jan 31, 2003 1:09 PM
built up (without the stem), bring it to a shop and do a little trial and error. Or, order a 110 (a "not too" size -- middle length) work it out with a shop and see if they'll trade you a different size for the one you get on the bike.
Stems are trial and error and dependent on top tube length and saddle position and flexibility and are probably the last thing to get dialed in on the bike. Stem position is also damn subjective.
What is your experience level? I don't quite know how else to say this, but this is basic stuff that you would have already learned with very minimal experience or at least probably should be getting from your teammates rather than from some anonymous dudes on the Internet. Are you a junior? The bottom line is that stem length is something you need to figure out for yourself with a little trial and error, because no one, no matter how experienced or knowledgeable, can fit someone's stem at least without having bike and rider and stem and trainer right there. Even then you can only help; you really can't do it.
The usual fit adviceKerry
Feb 1, 2003 9:25 AM

For adjusting the fit of the bike, there are roughly five starting points:

1. Seat height (top of saddle to center of pedal axle) at 108-110% of inseam.
2. Saddle parallel to ground.
3. Saddle fore/aft adjusted so that a plumb bob from the bony protrusion just below the kneecap passes through the pedal axle when the cranks are horizontal. This is known as KOPS (Knee Over Pedal Spindle)
4. Front hub axle obscured by the handlebars when riding in your "regular" position (drops, hoods, or tops).
5. Top of handlebars 1 to 4.5+ inches below the top of the saddle depending on your flexibility and size.

These are all starting points for "average" proportioned people, and many folks like to move away from these starting points as they learn what makes them more comfortable, powerful, or efficient. You want to get the fit of the frame as close as you can, then do minor adjustments with the stem, seat post, saddle position, etc.

A lot of this is personal comfort, and we all tend to adapt to a given position over time. For example, a given stem length may be right for you, but it may feel long at first. I use the "handle bar obscures the front hub" rule for my fit, but others claim better position (for them) with the hub in front of or behind the bar. I'm 6' tall and ride with 11.5 cm drop from saddle to bar, probably more than most people would like but fine for me. Some are suggesting zero drop from saddle to bars - it's about comfort, efficiency, and aerodynamics. The ERGOBIKE calculator is pretty good, but it is not infallible. I would suggest riding some miles (over 100 total, and over 500 would be better) and see if you adapt to the position. There are no hard and fast rules, just general guidelines, when it comes to these things.

Just as important as your size is your flexibility. If you have a stiff lower back, you may not be able to lean over and stretch out as much. If you are very flexible, you may get away with a longer top tube, with the stem in a lower position. Over time on the bike, too, you may become more limber, or at least become accustomed to being lower and stretched out. So, your first 'real' bike may not be anything like what you will want 5 years from now.

Someone new to road riding is highly unlikely to find their ultimate position on the first go. As they become accustomed to the riding position and get some miles in, sometimes over several seasons, people often find their desired position changing. What was "stretched out" now feels OK, or what was "just right" now feels cramped. With time, if you are working on your position along with all your other riding stuff, seat position tends to rise, handlebars tend to be farther below the saddle, saddles tend to move rearward, and handlebars tend to be farther forward from the saddle. You simply cannot say "this is the right position for someone of your body dimensions" because there are too many variables and things that change with time. Get used to your position, and then occasionally make small changes: raise/lower your saddle, move your saddle forward/backward. Ride a while with the changes (a few 100 miles, anyway) and decide if it is better or worse. If it is better, keep moving in that direction. If it is worse, try moving the other direction. If you don't try, you won't find out, but it is a long term process, often taking years, to really dial in your position. And since your strength and flexibility are changing with time, it is reasonable that your position would need to change also.
re: How to choose Stem length?innergel
Feb 7, 2003 7:18 AM
There is a good article on choosing the proper handlebar width and stem length on the 3ttt website. You just need to take a few body measurements and do a quick table lookup. That will get you very close.

And as always, your LBS should be able to verify this figure and make all the final adjustments.