rrgmrg wrote:

> I am trying to choose between two stems for a new road bike that I am putting together (head tube

> angle of 73.5 degrees). One stem is listed as -10 degrees (Deda), one as 80 degrees (ITM). I'm

> confused. What's the difference ?

None, they're just different ways of describing the angle. 90 degrees is aka 0.

> What stem angle will result in a stem that is parallel to the ground, 16.5 ?

-16.5 or 73.5.

> How much does a 10 degree difference affect the reach to the bars ?

That's one for the mathematicians

Will make slighltly shorter. Don't forget the height you set it

at will make a difference to reach too, so take into account how much steerer there is to play with

(<- assuming threadless ->). If it's cut short, you may well have to use a positive rise stem, ie.

greater than 90 degrees. This angle can also be obtained by flipping a negative rise stem, eg. an 80

upside down becomes a 100.

I know it's difficult to calculate what you need. I'm going through the same thing at the moment.

~PB