Your pump was available on fully equipped Frejus' of the late 60's through early 70's. There were quite a few variations of Silca pumps over the years since the company began . Very briefly, Silca Impero pumps from the 50's through early sixties era were marked with the word "Pompa" in addition to the word Impero. There were quite a few variations in the embossing design of both "handle" end as well as aluminum sheath, but I would fail at attempting to describe in words. Three diameters of pumps were available depending on length. Small diameter pumps were used for taller frames, medium diameter pumps for smedium sized frames, and wide diameter pumps were for short frames. Silca produced pumps in large batches for many Italian framebuilders, including Bianchi, Masi, DeRosa, Frejus, Legnano, and who knows which others.
The earliest Silca pumps were not made of plastic but of celluloid, but the use of this material was abandoned when a fire completely ravaged the plant in 1935. "Silca" is actually an anacronym for "Societa Italiana Lavorazione Celluloidi Accessori" and the company started out by manufacturing bicycle and motorcycle handgrips in 1917.
Use of both plastic and (some) celluloid pumps continued through the 50's, when the company then began development of ABS palstics for their product manufacture. It was then that the "Impero" was born - an name that came into existence for the characteristics of impregnating colors into the plastic (note - silca pumps are not painted!).
The silca Impero frame fit pump, with sculpted handle head to fit the underside of the top tube/seat tube area, was introduced in 1972. The next year they introduced the famous floor pump, which has changed very little over its evolution to today.
There were also variations in pump heads. Initially, these were made of cast white metal (muntz metal) and were prone to decay and failure. Aluminum heads were introduced in the 50's and were common on most Silca pumps through the sixties, but were usually abandoned in favor of the much better quality Campagnolo pump head that was develped in teh early 50's.
Ken Denny Boston
>From: "swampmtn" <swampmtn@siscom.net>
>To: <classicrendezvous@bikelist.org>
>Subject: [CR]skinnier Silca pump
>Date: Wed, 21 Feb 2001 19:04:27 -0500
>
>I have an old Silca pump which is about 3/4 as big as the normal frame
>pump. The handle reads "SILCA ESPORT. MILANO" and "Prodotto Italiano" same
>as the 1960s pumps I have, but instead of the IMPERO crest it's labelled
>"Frejus Torino Campione del Mondo 1930-33
>
>please see 6 pics at:
>http://albums.photopoint.com/j/AlbumIndex?u=1225372&a=11709831
>
>Any guesses how old this could be? Thanks for any info.
>
>Aldo Ross