OK the two things still commonly measured or specified in inches workdwide are:
Tyres (hence wheels - a mark to Andy) - rim diameter in inches (pouces or zoll)
Chains (whether bicycle, cam, or ship anchor) - pitch is in inches
Bar is neither metric (SI) nor imperial, it simply is 1 atmosphere (at STP). However it is almost metric, as 1 bar is almost exactly 100 kilopascals (kPa), the SI unit of pressure. In imperial, one bar is 15 pounds per square inch or 34 feet of sea water (interestingly, again almost metric as this is close to 10m!)
Most calculations are easier in metric, and the sooner we all accept them the better IMVHO.
The USA, of course, is moving towards metrication inch by inch...
