Shear and its connection to star formation. Upper panel: shear evaluated from the stellar component of the circular velocity within each IRAM-30 m aperture as a function of the radius along the bar major axis. The black cross indicates the mean bar range covered by the IRAM-30 m pointings (x-axis, i.e., FWHM/R_bar) and error on Γ_⋆. The latter corresponds to a 13% typical uncertainty on the slope of the disk+bulge rotation curve (Díaz-García et al. 2016b), which is associated with the uncertainty on the disk thickness determination. Lower panel: as in Fig. 7, but colour-coded by the stellar contribution to the shear. The grey contours show the measurements from Bigiel et al. (2011).