Fit gurus/math nerd help needed

[ariw]

Had a fitting for a new bike yesterday, and changing current rides to match my ideal fit requires a change in reach and drop. Reach needs to come back 25mm, so that is simple, but drop needs to come down 15mm on one bike and 30mm on the other.

I currently have 110mm 6 degree stems on both bikes, with both pointed up. Was thinking about just getting a 90mm stem and turning it to -6 instead of +6 for one and maybe the same but -10 degree for the other.

Any ideas on getting this as exact as possible with a simple stem swap?

Tia,
Ari

[fa63]

Try this:

http://yojimg.net/bike/web_tools/stem.php

Or this:

http://brown-snout.com/cycling/tech/_stem-calc.html

Or go to bikecad.ca if you want to model your whole bike :D

[Louis]

I wouldn't change both bikes at the same time. Change one and ride it a while to see how that works out. If it does, then change the other. If it doesn't, then it will be easier to go back to what you had before.