BMW Motorrad Spezial

Don Castro Triumph Flat Track

This beauty isn’t a show bike from the 70s: it’s the actual factory ‘Red Line’-framed 750 cc Triumph ridden by AMA Flat Track star Don Castro. The psychedelic streamlined bodywork came from a sponsor called The Fiberglas Works; it was outlawed by the AMA for violating the anti-slipstreaming rules after just one outing, at the 1972 San Jose Half Mile. The Bonneville-engined bike has since been restored by Don Miller of clothing company, a long-time supporter of vintage racing. “The whole resto has been off and on for a long time. I started by obtaining that bodywork over 10 years ago, from Don [Castro]. The rest trickled in over the years,” Miller says. “Luckily I grew up when that kind of painting was cool and did a lot of custom van and bike stuff myself. I spent 6-7 days re-creating that beast. That’s with drying times, burying flake under clear, multi-colors and effects, sanding and rubbing to perfection, then hand lettering The Fiberglas Works and Don’s name on the back.” The effort was worth it: Miller now has one of the most beautiful flat track motorcycles of all time in his garage.

Image via Jockey Journal. Head over to Triumph Flat Track for more supercool vintage Triumph action.

  • francois

    The lower muffler is dented and, if you look at the photo closely, you can see that the tank is zip-tied to the frame over a protective covering of….what is that?…plastic water pipe?

  • Adrian

    That’s a cool old ‘tracker , I saw it at Detonation ’08 in Brooklyn ,I have a left side view of the motor if you are interested.

  • That is a one piece fiberglass seat and tank unit, had some pics of the original advert and article somewhere. Very popular in the 70’s

  • To answer a few questions. The pipe got dented when I took it to Mid Ohio when Triumph was the mark. The front of the tank is held on by wire ties and it has pieces of fiber reinforced hose around the frame. Same way Castro had it then.

    Sorry to say it is a filthy picture. When I posted it at first, it was a lot cleaner.


  • Proof the seventies weren’t as naff as what some say they were.

  • RetroGrouch

    Dig the Seventies funk. Outta sight brotha!

  • frank newman

    what a trip, i was a 12 year old kid in 72 , I got to see Don Castro ride that bike at San jose, If i remember right he won his heat race, can’t remember what he did in the main event, Anyway this photo brought back some fond memories

  • Dan

    Just an FYI; thanks Don Miller for the photo and the work you did in restoring a legendary bike back to what it most likely looked like back in those days. Donny is my neighbor and I can say without a doubt he is a fine man and very modest and fortunately will be inducted in the Hall of Fame shortly.