I saw a post on here about a bent frame and made the mistake of looking at my Kinlon kbr 200! By eye it is two inches out and back wheel placement skewed in the assembly to correct that ... well it does feel a bit weird in the back end but the path of wheels through mud shows a straightish line. As I have had a few bolts fall off (the old joke about chinese bikes but unfortunately true) I will disassemble the bike in a couple of months which will be winter here and 'get to know it better'.
What is the best way to measure a frame to check for straightness? I can have the wheels out when I do it. Is it a simple case of diagonal measuring?
And does anyone know of a standard for strength of automotive nuts and bolts in Australia or is it just a case of materials used? The local hardware store looked at me blankly when I asked about tensile strength of the products they have available.

Just a grumble, I have found four bolts missing so far, luckily none are immediately dangerous. I thought the joke about them was just that, a joke, but it isn't. These chinese manufacturers HAVE to improve on such things and on back up/response to queries. Maybe a central call center for all china bikes funded by a consortium of them to start with, a couple of chinese/english speaking engineering graduates with proper manuals and parts lists and a computer setup for ordering parts would be all they need! Japanese bikes now own the world market because they backed up, Hyundai cars did that too and within a couple of years were winning 'car of year' awards. I wish Kinlon would do the same ...