Jake Herzog’s Grumph and GROSSA

Reader Contribution by Jake Herzog
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Reader Jake Herzog aboard his Greeves-Triumph.Photo courtesy Jake Herzog.

The piece on Greg Lawless’ Grumph in the March/April 2017 issue really got my attention as this combination was not uncommon here in the Northeast during the mid- to late-1960s.

I rode Greeves and other 250cc British machines in the earlier 1960s, but as a rather large guy I craved more displacement for offroad competition. One weekend a friend and I dismantled the beautiful T100C I bought new in 1964, and put the engine in a Greeves frame someone had donated. No high tech tools or product sources, just a set of torches, a portable welder, a 9-inch hand-held grinder, and electric drill.

The bike carried me to A Class in New England enduros in one season. The only major modification during the season was to add screen door springs from the hardware store, mounted to pull up on the back of the front swingarm. The springs helped the “rubber in torsion” overcome the added weight of the engine, heavy skid plate and rider.

Getting serious about competition in 1970 the engine went into a Cheney Frame, using a Triumph rear wheel, Ceriani forks, and a Greeves front wheel. The Hodaka gas tank from the Grumph was carried over, too. The Cheney was retired from competition in 1973 and used on the street until 1975. After languishing in the shop attic, it will be coming back to life this spring.

The Greeves frame that once held the Triumph was donated to a local enthusiast a few years ago, but my fascination with Greeves conversions didn’t end there. A few years ago I got interested in MotoGiro, which is sort of an on-road version of the old enduros. Starting with an OSSA Pioneer set up for highway duty, then moving to a 250cc OSSA Wildfire, I got thinking it would be fun to build something special.

I had a Greeves Challenger with a bad engine out in the Morton building, and an OSSA 250 Super Pioneer motor in the shop attic. During the next three winters they became a GROSSA. The conversion took a lot longer than the Grumph, as I now had a well equipped shop with TIG welder, lathe, Bridgeport, etc., plus 50 more years of experience. Gone were youthful haste and impatience. The machine wore rust and primer in 2015, as a few bugs were worked out over nearly a thousand miles. It was disassembled, painted and polished during the winter, and proved fun and dependable in 2016, participating in three MotoGiros, a vintage ride, and several short rides for another thousand miles.

We are looking forward to May 2017 and the MotoGiro in Asheville, North Carolina. — Jake Herzog/Slingerlands, New York

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