This could be the novelisation of the [film *Deathsport*][1].  It does not refer to [the novelisation][2] (by William Hughes) at all, but it is [on Goodreads][3].

The novel has elements of mysticism and the main character is a "Range Guide", which is a type of warrior who uses a motorbike.


  [1]: https://en.wikipedia.org/wiki/Deathsport
  [2]: https://www.isfdb.org/cgi-bin/pl.cgi?276597
  [3]: https://www.goodreads.com/book/show/9260865-deathsport