Thought you might be interested to know about this HD Koslow, an obscure and very rare OHV conversion of a Harley Flathead. Koslow? Owner Barry Brown gave me the 411 on his bike. When in 1931 Ignaz Schwinn, the owner of Excelsior/Henderson Motorcycle Company in Chicago, decided to shut down the business, one of his engineers named Andrew Koslow, an active hill climber and owner of the closest franchise to the actual factory, had a plan. At the time OHV Excelsior big Bertha hill climbers Gene Rhyne (Crocker future engineer) and the legendary Joe Petrali utilized a twin port hemi head configuration. So, Andrew Koslow made up a new set of castings using the Excelsior top end as inspiration, and converted the big Flathead VL’s to use in the then popular midget car racing. Andrew Koslow ran his motorcycle shop through the 1930’s up until the early 1950’s but never built a complete bike!
Barry Brown’s HD Koslow was built 10 years ago as a 50’s style Bobber around one of these conversions using all period pieces. He started out with a Koslow OHV conversion of a Flathead squeezed into a VL frame. The engine heads and cylinders were unique, cast by Modern Casting, (same outfit HD used) but used knucklehead rocker arms. Maybe more than what you want to know, follows the list of parts and modifications making this machine so unique (only 3 conversions are known to exist).
The Koslow has an heavily beefed up left side drive case and unlike the 2 other Koslows is running twin carburetors (twin Linkerts on individual manifolds). Stainless push rod covers and oil lines. Twin port exhausts (4 pipes, with the 2 left styled after the Harley 45 European road racer pictured in Wright and Hatfield. Engine displaces 84″ engine and runs a UL full flow oil setup.
Oil tank is an air dryer from a Mack truck! Cast alloy gas tank is heavily modified with period in-dash tachometer. Hand made stainless steel battery box and primary with 2 row chain and tensioner. John Cameron inspired Ford hub cap stainless vented derby. 1936 and up style 4 speed transmission. Modified forward frame mount cop shifter. Flanders bars and risers. Strutted VL forks with double Brough Superior style dampers. Twin front brakes activated by Vincent type balance beam. Star hubs laced to 19″ VL rims. Headlight is a spun brass spot taken off the roof of Barry’s 1936 Ford fire emergency rat rod. Crocker “limp dick” taillight”. Crocker magnesium tool box with custom made tribute plaque to Harry Buck who traded him the Koslow engine for a Militaire one!. Barry did cast the bronze floorboard with the Koslow logo in them. Dan Pugens WR pillion (a work of art made with old HD saddle bag leather)
Recently, Barry Brown went to Chicago to show and start the bike for the Andrew Koslow’s grandchildren who still run a shop, but not about motorcycles, now just Chinese made Schwinn bicycles! The HD Koslow bike deserves a better video than the one below…