Haven ridden a number of bikes of mine with these gears I would agree with Mike about the lack of noise being one of this type of gear's assets. However for road racing the very fact that riders will move over for you to change gear indicates that you were at a serious disadvantage over your cable-operated derailleur competitors. I would also agree that they were pretty robust and I think that many problems that arise from this type of gear these days result from dropouts not perfectly aligned. Originally these gears were supplied with I think mostly with special freewheels. Also these gears do take a lot of practice to use well at one time I rode one fairly regularly but I would still throw a chain occasionally. I have an Olmo light touring bike picked up in Florence some 15 years ago with a two lever gear it features a special freewheel with twisted and hooked teeth to improve the gearchange. Incidentally this machine has to be one of the most peculiar ever to to be built with type of gear flat bars with braze-on brake levers, but a lovely Olmo stem with the expander bolt being buried beneath a screw on Olmo badge. But the final touch is the really tricky one a half chaincase. The fun and games that result when the chain derails which it does occasionally have to be seen to be believed. I would also agree with Mike about the Gran Sport gear it does not change very well but it quickly became a favourite with the pros because it was robust, easy to set up and its poor shifting performance never changed until it was completely worn out. The Simplex mechs of the period had a far superior shifting performance but were much much harder to set up initially spring tensions needed to be adjusted just so, and adjusting the fore and aft throw took 10 or 15 minutes. They were also more prone to accident damage and wore out quicker.
Hilary Stone
Mike Barry wrote:
> I have a number of bikes equipped with Campag Paris-Roubaix and Corsa
> derailleurs. I disagree with Charles Andrews when he says that they become
> quickly worn and do not work well. My 1952 Bianchi has been ridden a good
> many miles since I bought it used in 1955 and it still works like new. In
> the early years I would use it on early season training rides and although
> changing gear while in the middle of a fast moving bunch can be exciting,
> the other riders got to know that when I reached back for the joy stick
> that they should probably give me a little more room. With some practice
> it is possible to change to any desired sprocket with only a half turn back
> of the pedals. It is always wise to try to avoid changing on a very steep
> climb when even a half turn back with the pedals can bring you to a
> standstill. A change should take only a couple of seconds at the most.
> Not quite your Ergopower I admit. The Paris-Roubaix is a beautiful piece
> of bike equipment. It is extremely well made and was far better made than
> any other piece of bike equipment of its time, and dare I say, almost
> anything available now. A bike equipped with one is a joy to ride as it is
> completely silent and free running as there are no pulleys running on the
> chain. The Corsa derailleur takes a bit more practice to use as there is
> one lever to release the wheel and one to select the gear. (All this is
> done with one lever on the P-R). I have an old 1949 Paglianti which I use
> for commuting on occasion which is equipped with a Corsa. I must admit it
> doesn't get changed very often, maybe once to the bigger cog going home,up
> hill, and onto the smaller cogs in the morning on the way in. It is silent,
> simple and a good conversation piece. It is interesting that the Italians
> continued with these derailleurs long after the guys on the other side of
> the Alps had fairly normal cable operated, forward pedaling Simplex, Huret,
> and Super Champions to name just a few. The Campag Gran Sport was a nice
> derailleur but really very little better, if any in operation than the
> French ones.