Strix the harbinger
guards the exit gate, quizzing all
Who will pass this night?

Monday, March 1, 2010

Cambio Corsa

A really short history lesson. Short because I am NOT an expert on this. I have only tried this once and that was only because Dan Ulwelling enjoyed watching my ineptitude. There have been rear derailleurs that we would recognize on touring bikes dating back to maybe the 1920s. Racing bikes were single speed and anyway these were not feasible for racing bikes. The early derailleurs were mounted forward of the freewheel and wrapped the chain around the freewheel cogs, making wheel removal difficult. With the rough roads and primitive tires, there were a lot of blown tires and speed was essential. Also, keep in mind the riders carried tires wrapped around their shoulders and were responsible for the changing the tire on the existing wheel, rather than have a a tire mechanic jump from a support car and slap in a new wheel. 


As you read this, please keep in mind your finger-touch brifter indexed shifters. To shift the Cambio Corsa, the rider had to free the axle tension with the long lever so it could slide fore and aft, then move the chain to the proper freewheel cog with the shorter lever, backpedaling to shift to a larger cog - forward to shift to a smaller (I think), then retighten the axle in it's the new position. Having never mastered this, I can only compare it to double clutch downshifting and  engine rev upshifting old straight-stick truck without synchromesh. Only ... I could actually do that. 


This is Masini's newest find (more later).  It is curious because Tullio Campagnolo invented this device in the mid 1940's, and later models, the early 50s Paris Roubaix, had just one lever. By 1952 Campagnolo came out with the Gran Sport derailleur, which most of us would recognize as "modern". This bicycle is apparently from 1955. Why was it made with, what was by then, an obsolete shifting system? Was it for an older racer that didn't trust the new fangled equipment? The 1955 date is based on the date on the bolts. Maybe this bike sat around, not built up, for three or four years? Whatever, it it very cool.
(Please correct as necessary.)

9 comments:

Masini said...

As I understand it, most racers at the time were afraid of the friction caused by jockey wheels in the derailleurs! That's why this system and others like it (Vittoria Margherita - now there's a strange system for you) lasted so long.

Again - I've invested my "retirement bikes" on this novel system... don't bring me down!

Gunnar Berg said...

I also understand that the full chain wrap of the touring derailleurs was an efficiency issue too.

I am certain that without tension of the springs and friction of the jockey wheels you will just fly! Particularly if you were to end up in some random, arbitrary place like Iowa or Minnesota, where you wouldn't have to actually shift the damn thing.

Anonymous said...

I also suspect it's sort of like touring cyclists nowadays, who eshew brifters due to the possibility of catastrophic unrepairable failure far from civilization. Ordinary cyclists who actually ride with brifters would most likely estimate the chances of such failure as roughly analagous to having the planet Venus crash into the main deck of an ocean liner during your first Bermuda cruise after retirement, but hey, better safe than sorry.

mw

Gunnar Berg said...

Chad? When summer comes can I take another crack at the Cambio Corsa, what is it, Bottechia?

Mimbres Man said...

That's badass! I want one!

There is something to be said about friction of the jockey wheels and efficiency. Having ridden my mountain bike as a single speed for the past 3-years (just put a derailleur back on it 2 weeks ago...now a 1x9), single speeding is more efficient than a derailleur bike. I can climb paved steep grades (>10%) with a 32x18 and 26" knobbies. I can't do it in a similar gear ratio with the cassette/derailleur set-up.

Anonymous said...

wow, an incredible feat of coordination....I can imagine losing a finger or two in the process while up shifting with those levers being so close to the spokes in a loose wheel--Yikes!

Allan Pollock

Gunnar Berg said...

On another blog someone mentioned that Bartali could shift a Cambio in a sprint!

reverend dick said...

Wasn't one obligated to let the wheel walk back or pedal it forward in the dropouts (while moving, obviously) to get the new gear as well? Frightening.

Anonymous said...

perhaps with a quick feather of the rear break to work against pedalling would allow the pedalling force to pull the wheel in the dropout. still, I'm amazed

Allan