The question is about FC-M739 model (1998 model year).

For this model Shimano lists 110mm BB length for 47.5mm chainline and 113mm for 50mm chainline. But is is known that 110mm BB is asymmetrical, the non-drive side being 3mm longer, though 113mm BB is symmetrical. So at least in one case the left and right Q-factors will be different - or, in other words, left and right pedals will have dirrerent distances from the center of the frame.

1. Does anybody know in which case (110 or 113) pedals will be more symmetrical?

2. Any idea about the reason Shimano changed symmetrical 107mm BB (which is listed for older M737 model) to 110mm? Note once more that all difference goes to non-drive side!

Thanks in advance for your answers.