Rounding Of Values

If your bicycle has horizontal, or track dropouts then leave the 'Adjustable Chainstay Length' box ticked. In this mode ChainlengthCalc rounds up or down from its calculated shortest possible length value to the nearest whole link either way. The assumption is that you will be able to move the wheel slightly forwards to cope with a rounded down value. A good rule of thumb is 1/2 inch of error due to rounding requires up to 1/4 inch of chainstay adjustment to compensate.

If your bike has vertical dropouts and you haven't got a 'Park chainstay shortening tool' then rounding downwards is a bad idea. So uncheck the 'adjustable chainstay length box' and ChainLengthCalc always rounds upwards to the next whole link value.