I was curious so I did some searching and it appears to be a circa 1990-ish K75 S, like this one:
http://www.motorcycles-bike.com/Moto...75-S-8502.html
Some info from Wikipedia:
https://en.wikipedia.org/wiki/BMW_K100#K75
Actually, if this info:
http://www.bmbikes.co.uk/schemepages/schemek75s.htm
is correct, the Royal Blue color was only produced in 1992 (the last year for that generation of the K), meaning it must be 1992 like the one I linked to.