found at http://www.hkstrida.org/forum/index.php
It seems that I have to explain the thing. 
http://www.hkstrida.org/forum/viewtopic.php?f=12&t=5496
One day, a guy brought a STRXDA tied with a string to a bike shop while the poster was chatting with the shop owner. The poster recognised that it was an SLO, so he didn’t help him and neither did the shop owner.
They looked at the SLO with curiosity and found that the steering pin was upside-down. Futhermore, the bottom tube was buckled with the fallen steering pin. 
The poster didn’t understand why it could be like that, so he told him using an allen key to remove the steering pin and then… However, the guy just ignored his advice and continued to fiddle with that thing. 
Finally, the guy tied his SLO with the string again and pushed it away. 
Many thanks to Amuro for telling us the whole story,
I’ve supposed that this is a SLO (the shape of the brake disc!).
Actually, you can’t just recognise an SLO only by the shape of the brake discs because the early batches of Strida 5.0 also came with wavy brake discs.
http://web.archive.org/web/20070714122635/http://www.mingcycle.com.tw/plaza02.htm
http://tw.myblog.yahoo.com/Skywalker-Strida/article?mid=155
Thanks again - for sharing your knowledge! 