When I first started riding again, I have had numb hand issues. I added bar ends to my stainless Dahon Classic III. On my Dahon Jetstream P8 I first bought gel gloves and then I installed the Ergon GR2 grips with ends. These grips are wonderful, but I still didn't care for the fixed height handlepost of the Jetstream. I bought a telescopic handlepost like the one on the Speed P8 from Dahon and installed it last night. Very easy swapout.
I love the added adjustability of my ride now. I will take more photos this weekend and go into more detail on the differences between the two handleposts as well.
One thing I completely overlooked when I ordered the part was the foldability. The Jetstream was not the most compact folded bike to start with. The big difference between the fixed and adjustable handleposts are the side they fold down on. The stock fixed handlepost folded to the right (outside the bike fold). The telescopic handlepost folds to the left (inside the bike fold). To my surprise it really did not affect the folding.
If you attempt this swapout you will need to make sure that you use the center screw and washer that comes with the fixed height handlepost. This is larger than the one that comes with the telescopic handlepost.
I will post more info and pics later, but I wanted to go ahead and share my latest tweak.
The first photo is with the telescopic handlepost. The second photo is with the stock fixed height handlepost. The photos are from different angles so it is hard to tell the height difference until you look at the shifter cable and brake lines.