Originally Posted by
gsteinb
I'm picking up a new bike. My giants have 120 8 degree rise stems. While the obvious answer as to what stem to get in order to keep my fit the same seems to be get an 8 degree rise stem, a cursory glance didn't turn I'm much. I don't even really know if my obvious answer is accurate. Further I've been reading stem reviews and can't tell one from the others. I have a set of the same bars as a start. Thoughts? Suggestions? Help?
what's stack and reach on the old bike? how about for the new bike?
if it is not published for the old bike, you can measure it by putting it against the wall, measuring wall to HT and floor to HT, then subtract wall to BB and floor to BB, respectively.
that will figure out if you need more or less reach (or stack) than your current bike.
as [MENTION=92828]topflightpro[/MENTION] said, you can calculate all of this, but it depends on frame size, HT length, HTA, etc.
you didn't supply enough info (e.g. no models) for anyone here to provide more info.
as for stems....it's just math (trig) to figure out what length/angle you need. of note: some stems claim to be a certain length but can vary as much as 5mm IME.
congrats on the new bike.