I wondered about the cup's retention to the shell as I didn't notice any lip or flange that would bottom out against the shell's face. With the lock ring removed one would hope that the cup would easily be able (tool independent) to be unthreaded. However this not being the case makes me wonder about the condition of the shell's threading. Heat distortion, poorly cut (or unchased) threads or too much paint inside the shell are common reasons why an otherwise "unlocked" cup might not freely turn in the shell. So, if you are able to remove the cup, I suggest that you have the shell chased (and faced) with proper tools. One more reason to have a good relationship with a good shop. Were you close to me I would help out and this would be a fairly quick job, excluding other unknown issues.

Another poster suggested seeking a DaHon dealer. I was one briefly back in the 1990s (or was it late 1980s?). But the slow sales, the long build out of the box time required to make the bikes be of shop grade function (or as close as we could get them to be) and the lowering of quality we say over the couple of years we dealt with the company led to our discontinuing selling them. In the 2ish years we might have sold 5 or 6 bikes. But my shop was known for service and repairs more than bike sales. With that reputation and previous dealer status we say a few come through our service shop every year after (until 2000 when i close up the shop for good) and sad to say but the quality thing didn't seem to get better. DaHon began to sell direct to consumers and to offer their bikes as promo items for other industries' spiffs to their employes. needless to say the lack of feedback to the company didn't do any good WRT improving quality. Andy