Best tire combo IMO, and many others for dual sports are the Pirelli MT-21 front and the Dunlop D606 rear.  The 606 on the front can wash out, but the wear of the MT-21 rear is horrible and the 606 does much better on the rear....nice bite and better mileage.   I have the D606 on the way for me to put on down in New Mexico after I assume I will have almost no tire left after 1500 miles on the OEM MT-21.   I have heard NUMEROUS accounts of guys running the 130/90 18 D606 on the KTM 690 with no issues.  10 mm higher (1 centimeter) shouldn't hit anything.  It is also 'slightly' narrower by the 10 mm so theoretically it will dive into turns quicker/easier.  (miniscule)