The handlebar post on my folder was not a tight fit anymore and was moving about as I cycled, not a good thing. The clamp that secures it in place was loose and would not respond to any adjustment. The bike was bought second hand and the previous owner had replaced the original one on which you could adjust the height of the handlebars making it more versatile. Luckily I managed to find an original modified Dahon replacement on eBay sold by a dealers specialising in folding bikes.
A cycling blogger Annie is also a Dahon fan so hopefully she finds this useful.
Before
This is the clamp that was loose.
The fork tube is held in place by this nut and removed with an allen key and then another nut on the side of the clamp releases the steerer
With the forks out it's easy to clean and re grease the head bearings
The replacement is just the reversal of the above.
Should over time the clamp become loose its easy to adjust using the two bolts on the securing clamp so that it fits snugly into the clamping block.
After
The replacement steerer is lighter and because of the height adjustment it gives a choice of handlebar positions, so a better ride and a lighter touch needed for steering.
This replacement was relatively quick and easy and the most time was spent removing the handlebars and the bits and bobs I have on there.