Some of the most winningest & trickest motocross bikes i've seen built were..
1970's  were Trevor's Maico's & Yamaha's.
1982  Darryl Willoughby   Yamaha YZ490
1983 My Suzuki Rm500 & 250,  Darryl Willoughby YZ490.
1984 Jimmy Ellis Yamaha YZ125, 250 & 490, Stuart Bennetts  Yz490
  "     Ricky Murphy's  Suzuki RM500
1985  Jimmy Ellis  Yamaha Y125, 250 & 490.
1987 Jeff Leisk Yamaha  YZ250  (burswood supercross)
1988 Steve Dinsdale Honda CR250.
The most talented individual i knew in regards to suspension set up,  engine knowledge & race craft to this day,  Trevor could have run & managed any team in the world with great success.
His talent did'nt stop at motocross only,  He was very influentual  in road racing with Michael Dowson & Kevin Magee & the Marlboro Yamaha super bikes.
Great mentor & clever man !!!!