On Dahon Speed TR, I hate, I hate, I hate the little bity (but expensive) piece of HDPE plastic in the stem hinge latch that deteriorates over time. [Same issue on Dahon Helios but slightly different part] Both more than 10 years old. I wish I could fashion this piece my self.
On Bike Friday Tikit, Creaks and Flex under load. The manufacture recommended taking a rubber mallet to the catch.