About the dropouts on this bicycle?

[cyclingthelakes]

Get the set up on the back drop outs of this 1951 Legnano bike. (article: http://www.ebykr.com/2006/07/tech-specs ... a/#more-66 )

Can anyone clue me in as to what is going on here?? Allow me to up load the photo.

It almost looks like the seat stays would be adjustable, I would guess though it is just to keep the back wheel tight the way skewers do, tighten it up, it just looks real complicated.

I know this is more of a vintage bike question but I thought I'd submit this question anyway.

Thank You.

[broadway]

Its a "Campagnolo Paris-Roubaix gear mechanism" see classic lightweights for an explanation.

" For those who are not familiar with the gear it works as follows: the top of rear drop-outs are notched and these coincide with notches on the axle. There is no chain tensioner at all – as the gear is changed the wheels walks backwards and forwards to keep the chain relatively tight."

http://www.classiclightweights.co.uk/campagnolo.html

[enigmatic]

What broadway said Signor Tullio Campagnolo the father of the dérailleur gear
http://www.campyonly.com/history.html

[scottg]

Standard Cyclo (1924)and Osgear (1928) predate Tulio.

Here is the estimable Aldo Ross showing how to shift your new P/R.

http://www.wooljersey.com/gallery/v/ald ... 9.AVI.html

[enigmatic]

I had an Osgear once. Until it took 6 spokes out of my back wheel. Likewise an old Cyclo Benelux took two spokes out. Campag never did that

[thirdcrank]

AFAIK the big Campag invention was the q/r as outlined in enigmatic's link and any number of other accounts about the Croce d'Aulne. I think the Paris-Roubaix design derailleur (which I've only ever seen in pics) was a misguided attempt to extend the use of the q/r. I presume that the sprockets were a fixed wheel arrangement to allow the rider to manoeuvre the wheel back and forth? He got right back on track with the parallelogram system. Campag also brought an excellence of quality to bike equipment which has never really been matched (not even by Campag in recent years) and certainly not by another mainstream manufacturer. Overall, I don't think the Campag record of inventiveness was a complete success (apart from the q/r) and there have been a couple of pups - the original bar end levers being my nomination for a good idea, badly executed.