[QUOTE="Champ"] Do you make this stuff up yourself, or did someone tell you down the pub?[/QUOTE] Neither Have you failed your MOT for a warped brake disk yet? When you do, take it home and measure it on a flat surface. Then you'll discover that the new computerised MOT brake test is slightly flawed to say the least. When your bike fails its emissions sniff on startup from cold, will your tester repeat the test on your no-brand aftermarket exhaust? If you are based in the West Midlands/Welsh border then the MOT testers school is applying a stricter code than darn sarf. Borg (The OP) being on the other side of the county line from me, will find his testers are taught at the same school as mine. If you bring an illegal bike (Divvie 600, V-Max, C90 cub etc) then you will probably fail with no appeal. If your bike is using genuine OEM parts then you can at least appeal. but this is only my personal experience YMMustV Dave