Table of Contents


Koski Overview

After building up many klunkers from his family's Cove Bike Shop in Tiburon, CA, and then helping his brother Don Koski and Mert Lawwill launch the Lawwill-Knight Pro-Cruiser in 1979, Erik Koski launched the Trailmaster on his own. Only 55 to perhaps 75 were produced over three years 1). Koski resurrected the brand in 1998 to co-produce a Titanium version with Steve Potts 2). See also: mmbhof and mombat.

koski
Erik Koski 1988 mombat


1980 Trailmaster

Designed by Erik Koski and built by Dave Garoutte. See also: DKG Museum.

1980 Koski Trailmaster
1980 Koski Trailmaster #2 SFO museum


1982 Trailmaster

Offered for sale 27 Dec, 2021 for $8,000.00 @ facebook

Atom drum brakes?

1982 Trailmaster
1982 Trailmaster facebook


1984 Trailmaster

“#51/53 built”. Converted to single speed. Originally with a 2×7 SunTour drivetrain. SunTour roller cams, PMW dropouts.

1984 Koski Trailmaster
1984 Koski Trailmaster #51 facebook


One more pic

Not enough credit is given to Erik Koski in the history books. Joe Breeze used Koski forks for the first set of Breezers. The Cove Bike shop printed the very first mountain bike catalog in 1980. Koski mountain bike components were sold for decades.

This photo comes from China Camp State Park were mtbtimeline personally used to ride off road in the 1980's each weekend - never once seeing another bicycle - probably because all the action was next door at Mt. Tam…

trailmasters
2014 group ride in China Camp, Marin blackmtncycles


Production Notes

[1]. As Trailmaster #2 was 1980, 1980 is a good guess as the start date. See: SFO Museum

[2]. Less than 100 Trailmasters ever built. Fat Tire Flyer, page 117.

[3]. End of production in 1982? Mombat Koski Catalog

1)
see production notes