Riser Stem?

[Catrin]

I called the LBS that I want to perform the fitting and just explained the situation to them. I do not have to wait to reach the requisite mileage before they will fit me. So I just have to wait for some money to come in that I am expecting and will schedule the fitting. I may still move the shifters to the bars, but won't do anything else until afterwords.

[OakLeaf]

Just so you understand the concept, and I hope I can explain this right, it isn't really the length of the stem that makes the front wheel twitch in response to every hiccup of your hands ... it's the handlebar offset.

Extend an imaginary line through the center of your head tube and steerer tube. Now draw another imaginary line, parallel to the ground, from the center of your handlebars/handlebar clamp, toward the rear of the bike. The distance from your handlebars to the line coming from your steerer tube is the handlebar offset.

To take an extreme example, let's say you've got an adjustable stem, and you set it so there's no angle in it at all (I don't think that's possible, but just for the sake of argument) - it just extends straight up from your steerer tube. Now, it doesn't matter whether that stem is 6 cm or 16 cm, you've still got zero offset, and the bike will be nearly unrideable.

To take a more real world example, it looks like your stem rise may be as steep as 45° (which is pretty darn extreme) - let's say for the sake of argument that you have a stem with a 45° rise, because that way I can use the Pythagorean theorem and don't have to try to remember trigonometry. (And somebody correct me if I'm wrong!)

Say you want an offset of 10 cm from a stem with a 45° rise. You've got an isosceles right triangle, with the offset line being one side and the stem itself as the hypotenuse. Using the Pythagorean theorem, you'll see that your stem must be a little over 14 cm (the square root of 200) to give you that offset. Working in the other direction, if you have a 6 cm stem with a 45° rise, your handlebar offset is a little over 4 cm.