In article <
[email protected]>,
[email protected] wrote:
> hi, just wondering what efffect stem angle and length has on handling?
> i'm assuming that a shorter stem is less stable but easier to corner
> with, etc and a longer stem vice-versa.
>
> what about when it's angling above, or below level? would that make it
> less stable? thanks
The most important components to bike handling are, in my opinion:
3) tire inflation
2) front end geometry
1) the nut attached to the handlebars
To understand the difference stem length makes to handling, try to
envision a zero-length stem, and a bizarre handlebar where each half of
the bar goes directly from that stem in a straight line to where your
hands would touch the bars (whatever kind of bars they may be).
Perhaps you can see from this example that the amount of leverage on the
steer tube that you have is a function of the length of this ridiculous
bar, and that the ridiculous bar will change its length by a very small
amount with changes in stem length, because the ridiculous bar is the
hypotenuse of a right triangle including the stem and the length of your
real handlebar from the stem attachment to your hands. a^2+b^2=c^2, as I
once told a worried nurse checking me for signs of slipping into a
coma....
Of more concern, handling-wise, is the tiller effect, which is to say
that really long stems feel odd, for reasons revolving around the paths
your hands take as you steer. I think the short version of this is that
it doesn't feel so much like you're moving one hand forward and the
other hand back, but rather that both hands are are swinging out in
front of you. To envision this better, imagine our zero-length stem
again, this time with a flat bar, and then imagine a bike with a really,
really long stem. Maybe 50 cm. Visualize how you would move your hands
to steer each bike.
I should caution that I am relatively insensitive to geometry and fit
issues until they cause me pain. I ride around on all sorts of bikes,
and as long as the seat height is right and I can reach the handlebars,
I usually make do.
Oh, as for your question about stem angle, no difference. That factor
should be solely about getting your hands at the right height for your
needs.
Probably wrong in some way,
--
Ryan Cousineau
[email protected] http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos