I may have missed it somewhere but I am wrestling to get the correct Chainline on a bike I designed. The major problem seems to be to define the length of the bottom bracket spindle. I can enter all values except this one. My OLD is 110 on a specific design where I would want to use a beltdrive system. The issue I get is that the front cog will either touch the right chainstay or whenever I use a longer bottom bracket spindle the belt will simply slide of the rear cog because the chainline is incorrect. I use standard tapered 68mm BSA BB's. Even when I try to build a bike with an fairly standard OLD of 130 I find no way to define or find my correct BB axle length other than trying. However trying should not be an option, the design has to give me the right chainline with the BB selected. Who can help me out? Thanks ;)
Bottom bracket spindle length
In BikeCAD, we don't enter a value for bottom bracket spindle length. Instead, we enter the dimensions for the cranks and chainrings as shown below. Note that dimensions F and W3 are found in a combo box menu, so only the selected dimension will be used to drive the design.
I trust you have the rear end sorted out, but for anyone else who's wondering, you can enter those dimensions according to the diagram below.
These are both found in the Drivetrain dialog box.