This Section is included as part of the longer Route 5: Section 5 (Solothurn-Ins). So I have not biked it again and my description of this path can be seen under Route 5:05 .
Its specific information from SwitzerlandMobility.ch can be found at http://www.veloland.ch/en/routes/etappe-0908.html. This is a short section of about 31km and basically flat.
Highlights include Büren a. A, the stork’s colony of Altreu and Solothurn
Links to Introduction & other Bike Routes/Sections: