In a message dated 4/25/2005 1:09:54 PM Pacific Daylight Time, CaptBike@sheldonbrown.com writes:
I've sometimes gone 1/2" above on my own bikes, but I'm a trained professional who rarely stands to pedal a multispeed bike.
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The issue is not the stress you put on the stem, it seems to me.
The issue is that if you clamp the stem too high in the steerer, you're clamping in the thread area. The stress will come from the clamp-pressure itself. If the stress is too high, the steerer will crack in the thread-area, and if it happens at the wrong time, goodby asphalt, hello traction, if you're lucky...
But then, you all know this, right?
I've measured a lot of steerer tubes, in the interest of raising a conventional Cinelli stem as high as possible...and I find that while it's sometimes possible to raise a stem a little beyond the limit line, it's not usually possible..unless you want to clamp in the threads, and I assume no-one wants to do that.
Seems to me the only way to do this is on a case-by-case basis, measuring the threaded area, and clamping the stem just below it.. or well below it, depending on how much of a risk-taker you are.
I'm not real thrilled with the look of a Nitto Technomic either, although I use them...because I have a long-standing neck injury that likes to irritate itself at the slightest opportunity. Higher bars help me avoid that annoyance.
I'd love to be able to ride with a lower stem and higher saddle, this posture is ideal for accelleration, consistent speed, and stamina, since it gets the big muscles into the act. I rode like that all the time when I raced, of course...I was younger then, too. All other things being equal, and in perfect condition (like your neck and back), a higher saddle and lower bars will make you go faster.
The more upright we sit, the less we use the big muscles....
One solution to this problem that I like a lot, but that is tough to implement with most vintage bikes, is to have a longer steerer tube, cut it off long, slit the top inch or so with a 1/16" slit, install the headset, and install one of those old-style steerer clamps that used to be fairly common (I'm told). You see them often in pics of bikes from the 50s and before. *Lightly* clamp your vintage stem to suit, then tighten down hard on the external clamp. Works great, and it gets the stem right up there. I have one of these on our old Pogliaghi tandem and it works great. It's been set up this way for 35 years, and many miles, and hasn't broken yet (knock on wood...if it ever cracks the steerer on a down-hill, we're toast).
The other solution was described in an earlier post...keep your shoulders down and elongate your neck when you're on low bars, to keep your cervical spine stretched out. If you let your shoulders creep up and put your C-4 joint under a lot of stress, you'll regret it, sooner or later.
Charles "master of the obvious" Andrews SoCal