|Reader Nigel Scott sent these
photos from his home in Dorset, England, of his very unusual 1951
Bianchi with a prototype of the "Paris Roubaix" rod-shifting
derailleur. This setup was very short-lived--1951 was the first
year of production for the Gran Sport derailleur, which set the basic
format for the cable-activated, dual-pulley derailleur that Campagnolo
stuck with for the next 40 or so years, and rod-shifters quickly dropped
out of sight.
Campagnolo's first successful derailleur had been the "Cambio Corsa," which used a system of seatstay-mounted control rods to loosen the rear quick release and then move the chain back and forth with a "fork" device. The fork sat around the chain on top of the chainstay, so that shifting occurred when backpedaling; since it had no jockey pulleys, the wheel moved back and forth to take up slack in the chain. Once the shift was complete, the quick release was re-tightened, and the rider could start pedaling again.
The Paris Roubaix was introduced later, and refined the Cambio Corsa into a single control lever. It shifted in the same manner as the Cambio Corsa.
The shifter on Nigel's bike is usually described as a prototype, but he reports that a number of similarly equipped Bianchis were imported into England--some are still on the road today, and at least one is being ridden daily.
The shifter in the photos below moves the shifting action to the run of chain below the chainstay (like the derailleurs we use today), so that shifting takes place while pedaling forward--a definite advance over the earlier rod shifters.
Scroll past the photos for Nigel's description of the bike, and his notes on shifting with this very unusual setup.
Nigel describes the Bianchi:
"I enclose photos of my 1951 Bianchi machine with the prototype (according to
The Dancing Chain)
Paris-Roubaix changer on it. You will see it runs on the lower row of
chain. There was a batch of these cycles imported into England at that
time although they all had the normal P-R changer and a number are
still in existence. I have seen one with a frame number just nine
digits higher than mine and another which is seventy-four higher. me is
#285446. A man I know bought one new and still rides it.
Shifting The Paris Roubaix"The gear works in the same way as the conventional Paris-Roubaix gear but the intention with mine is that you pedal forwards because the Lower row of chain is running thro' the gate. You twist the lever outwards and the change gate is free to swivel across the width of freewheel and you pedal GENTLY forwards to guide the chain onto the desired sprocket. When you tighten the long lever the little pawl engages the ratchet collar that you see in the close up photo and all in the same tightening movement turns the whole main axle and hub slightly forwards thereby putting a little slack in the chain.
When you change with a Corsa gear your weight automatically causes the wheel to travel backwards in the fork ends and you end up with a tight chain, this little ratchet overcomes this. The hub has the same splined axle but is longer to pass inside the ratchet collar."