I have an 120mm old quill stem that has a rise of 0 degrees when inserted into the head tube, ie, the stem angle is -17 degrees approximately. I want to buy a new road stem. All I'm trying to do is figure out what length stem a comparable 80 degree stem I would have to order to get the same type of length (ie reach) as my old quill stem.
...so, is there some sort of online calculator that will allow you to enter...
1) your old stem angle & length
2) and also enter in the new stem angle,
3) and allow you to calculate what length of new stem you need to buy