Age old question. What year is this prewar Monark ?

[10~18kustoms]

Picked up these two Monark pre-war frames at Haysville this weekend, and as usual I can't make any since out of the serial numbers using the widely inaccurate Monark serial number charts that are floating around.

I'm guessing the Flo-Cycle frame number 17838 is probably '36 or 37, and most likely '37 if the # chart is accurate? I am also intrigued by the upside-down 1 & 8's. Was it almost 5 on a Friday?

Next one appears to be an early Rocket motorbike (hanging tank) frame with the serial number 116273 stamped in small numbers on the right rear dropout. This one is really confusing since the serial number falls in the ? on the chart between '42 and 46. I always thought the wider hanging tank frame was discontinued in 39 or early 40 and the narrower bar frame was 40-early 42?

Any help or observations would be greatly appreciated!

 

[NBHAA]

Picked up these two Monark pre-war frames at Haysville this weekend, and as usual I can't make any since out of the serial numbers using the widely inaccurate Monark serial number charts that are floating around.

I'm guessing the Flo-Cycle frame number 17838 is probably '36 or 37, and most likely '37 if the # chart is accurate? I am also intrigued by the upside-down 1 & 8's. Was it almost 5 on a Friday?

Next one appears to be an early Rocket motorbike (hanging tank) frame with the serial number 116273 stamped in small numbers on the right rear dropout. This one is really confusing since the serial number falls in the ? on the chart between '42 and 46. I always thought the wider hanging tank frame was discontinued in 39 or early 40 and the narrower bar frame was 40-early 42?

Any help or observations would be greatly appreciated!

View attachment 1827094

View attachment 1827095

View attachment 1827096

View attachment 1827102

Your aluminum frame (not a "Monark" which would be a steel-framed bicycle) appears to be a Hawthorne Duralium rather than a Silver King. It has Hawthorne Duralium truss rods on the fork. Also, no way can it be 1937 (why?) since it does not have the mount for what I have always called the "butterfly stand" (yes, that term came from me). Therefore the frame in these photos has to be 1936... numbers or no numbers.

As for the steel frame... forget "1942-1946"... Monark-Silver King, Inc. only made a few bicycles in the early months of 1942. And most of those were lightweight, skinny-tire "Victory bicycles." From then until the end of 1945, they made no regular production bicycles– no matter what somebody's "serial number list" or "book" might say. Like most bicycle companies, MSK was prevented by federal edict from making more by the U.S. War Board (they determined what manufacturers could make during WW2). This is a late prewar frame, not an early one... and not just for the Rocket line, either.

National Bicycle History Archive of America has the paper archives of Monark-Silver King, Inc. We have numerous factory items and almost every catalogue for every bicycle they made since the beginning up until the end (the real end– not what people think was the end).

Leon Dixon
National Bicycle History Archive of America
(NBHAA.com)

 

[10~18kustoms]

Your aluminum frame (not a "Monark" which would be a steel-framed bicycle) appears to be a Hawthorne Duralium rather than a Silver King. It has Hawthorne Duralium truss rods on the fork. Also, no way can it be 1937 (why?) since it does not have the mount for what I have always called the "butterfly stand" (yes, that term came from me). Therefore the frame in these photos has to be 1936... numbers or no numbers.

Thanks Leon, you are correct! The aluminum frame is indeed a Hawthorne Duralium Air-Flow rather than a Flo-Cycle. I am not very knowledgeable with the early aluminum frame bikes and had heard/seen them all generally referred to as Flo-Cycles, but I later found an add from '36 showing the differences. Also, thanks for verifying the '36-37 question. I think I'm throwing that prewar serial number list out; it always confuses me!