Marty,
47 is the size pump you want for a 53 cm frame. I believe the next size up was 50, and that will be too long. You have the best head for that pump. Keep it clean and waxed, or it will rust over time if it gets wet. When the rubber covers deteriorate (which they might not do if you ArmorAll them periodically), dip the end of the pump in that plastic stuff for tool handles.
The way to keep the end of the pump from blowing off is, first of all, to not put the pump on a tire that has 80 psi or more in it. The safest thing is to let some of the air out first. I grip the handle and barrel of the pump together while I am putting it on the valve, or rest the end of the handle against the inside of my bicept so that it will stop the handle from moving out if air starts going into the pump. The Campy heads are pretty good about this, but the later Silca plastic head can allow the head to go on until it bottoms out against the end of the valve, pushing it open and filling the pump with the air pressure in the tire. If the user is not being cautious, and if there is nothing to hold the piston back, it will become a very effective rocket. As long as it doesn't knock someone's eye out, and if the angle of the pump is right, the handle can take a very exciting trajectory, really enlivening the pre-ride ceremonies. I saw one go across the road into a field on the other side, once. The tire will, of course, go completely flat and the erstwhile rider, in an attempt to preserve his manly pride, will then and ever after refer this model pump only prefaced with uncouth adjectives.
Steve Barner, avoiding homework in Bolton, Vermont
> Date: Tue, 9 Mar 2004 11:20:39 -0500 (EST)
\r?\n> From: mmeison@scubadiving.com
\r?\n> To: classicrendezvous@bikelist.org
\r?\n> Subject: [CR]Silca Imperio questions and WTB
\r?\n>
\r?\n> I've bought a NOS campy head for a silca imperio frame pump
\r?\n> (the one with the Y extension off the top), and am
\r?\n> looking for pump to go with it, prefer either chrome
\r?\n> or Blue sized for 53cm frame, which leads me to my
\r?\n> questions:
\r?\n> My first question is what size pump for a 53cm x 53 frame?
\r?\n> med? (47cm compressed I think,size 3?). I've searched the archives
\r?\n> but can't find anything on sizes for silca pumps.
\r?\n> Second question, in reading the archives I keep seeing
\r?\n> reference to keeping the back end of the pump from blowing
\r?\n> off. Other than holding both the pump handle and the head on the
\r?\n> presta valve is there some technique I need to know?
\r?\n> Secret handshake?
\r?\n> Previously used zefals, figured its time to get a real pump.
\r?\n>
\r?\n> thanks,
\r?\n> Marty Eison
\r?\n> Dallas, Texas
\r?\n> ------------------------------