A.
anwered by: canteau
Mounting the Soma Porteur to a bike with 26x2.0 tires should not be an issue but disc brakes might be. You might want to check out the Soma mounting instructions to confirm that your bike has the proper mounting points.
http://www.somafab.com/wp-content/uploads/2015/07/soma-porteur-rack-instr-dlx-2015.pdf