Bicycle Mechanics - Stem angle

I'm buying a new frame and fork, and I want to end up with a fit on the new bike that matches the fit of another bike I own. I wrote a program to calculate the fit (yes, I am a geek) in terms of saddle position, stem length, etc., but I can get the same approximate handlebar position with multiple combinations of headset spacers and stem length and angle.

So here's my question: is there any reason, aside from aesthetics, to choose a relatively high stem position with a small angle over a lower stem position with a steeper offset?

That is, is there a reason to choose something like this:

http://farm4.static.flickr.com/3584/3648475637_df3977337c.jpg

over something like this:

http://farm4.static.flickr.com/3575/3804820165_d62c457004.jpg

or vice versa?

Carbon steerers have a maximum recommended spacer stack under the stem. Some maker place the limit at 30 mm and others at 50 mm for 1-1/8" steerers. The limit is almost universal at 25 mm for 1" carbon steerers.

Steel and aluminum steerers aren't as limited but an up-angle stem and a shorter spacer stack should make for a less flexy steering feel.

You might also find a bit more stem flex(ie hand cushion) with the height taken up in the stem(2nd picture) over the steer tube, especially with a steel steer tube.

However I find downsloping stem to be sexy as hell

Picture 1 is really ugly and picture 2 is only a little better, since both have big spacers stacks. I like to keep the spacers down to 5-10mm if possible, but I refuse to use a stem angle greater than 84-90. No flipped stems for me. Right now I'm using a 73 degree (horizontal) stem with a 5mm spacer above the 15mm headset top section.

I agree with the whole too many spacers thing on the top picture, but I still prefer the downslope look of the stem-looks faster to me, I've always thought the upslope stems looked ********

For the OP- Your a geek right? Whats the shortest distance between two points? Embrace your inner nerd.

OMG bike forums just bleeped r e t a r d e d

Picture 1 is really ugly and picture 2 is only a little better, since both have big spacers stacks. I like to keep the spacers down to 5-10mm if possible, but I refuse to use a stem angle greater than 84-90. No flipped stems for me. Right now I'm using a 73 degree (horizontal) stem with a 5mm spacer above the 15mm headset top section.
All of that is just fine IF you have a frame that is large enough and has a head tube extending up enough to get the bars where you want them OR if you are flexible enough to have the bars well below seat level.

Not every one wants or can use the bars as low as a 73° or even a 90° stem plus a very short spacer stack will put them. Looks sometimes have to be sacrificed to practicality.

If you're running too many spacers, it's probably a good indication that the frame is a little too small for you.

Other than that, looks have to take a close second to fit.:rolleyes:

Picture 2 is actually of the bike I'm trying to match. I don't know if I have weird proportions or maybe I have weird preferences, but it seems like bikes that fit me in terms of top tube length and standover don't have the bars as high as I want them without one (or both) of the solutions above.

As it turns out I've actually come to like the up-sloping stem, though I admit at first I thought it looked screwy. It's nice to hear that if will offer additional benefits, however minor.

Thanks to all for the responses.

Picture 1 is really ugly and picture 2 is only a little better, since both have big spacers stacks. I like to keep the spacers down to 5-10mm if possible, but I refuse to use a stem angle greater than 84-90. No flipped stems for me. Right now I'm using a 73 degree (horizontal) stem with a 5mm spacer above the 15mm headset top section.

Beauty is in the eye of the beholder. I prefer the setup of the top photo over the up angle of the bottom. That said, I also prefer a custom made one piece spacer instead of all the little short ones stacked up no matter which stem angle is used.