Stoker Stem Length Question?
 

Working to fit my 12yo stoker on our T1000. She needs a bit more stem length, but I'm not sure what the lengths refer to when shopping. I measured ours at max extension from the "max line" to the split at the bar clamp is 70mm. Or should I measure from the middle of the captain's seat post to the split in the clamp?? Or am I off in left field (again) .

Thanks for any input!

Measure from the center of the stem's seat post clamp to the center of the handlebar clamp, along the line of the stem.

Then to complicate things, you also have to consider, how the angle of the stem effects extension, if you get a stem with adifferent angle.

http://www.habcycles.com/stemfit.jpg

To determine the angle of the current stem, if you have an iPhone or iPod Touch then download the "Clinometer" app and use that to measure the angle of the stem, and combine that with the angle of the seatpost that it's attached to (draw a diagram to make this easier), and then you'll know the current stem's angle, which you can compare to a new stem.