Campagnolo Euclid RD
 

A bit of an esoteric question...does anybody have information on the cable actuation of the early 90s Campagnolo Euclid rd?
https://cimg6.ibsrv.net/gimg/bikefor...b4687731d.jpeg

Good question. About 20 years ago I cleaned out an older shop of their NOS collection of these; the grizzled veteran (even then) shop mechanic complained that they could never get these derailleurs to work with indexed shifters. When I inquired about which shifters, the response was: "Shimano of course; indexed shifting is all in the shifters and has nothing to do with derailleurs". I agreed with his assessment that there must have been a manufacturing flaw in these as I tucked away a bag of them at great price. One of those situations where you pay, walk out the door in haste, and do not look back. So obviously, these derailleurs are not compatible with the 7/8/9 Shimano actuation ratio of 1.67:1.

I would put money at heavy odds that these derailleurs match the first-gen Campagnolo indexing actuation ratio of 1.43:1. I still have most of these derailleurs left, but in undertaking an indexing experiment by installing them on an older Campagnolo Ergopower system, they would no longer be NOS, so I would take a heavy hit on the value.

That makes sense…I’m going to buy this and will try it out with 10speed Ergopowers. If I’m not mistaken they have 1.5/1 cable pull ratio. Should work then. I’ll keep you posted…thanks!

As I posted above, these derailleurs almost certainly adhere to the old (pre-2000) actuation ratio of 1.43:1. Not the later 1.50:1.

With 10-speed Ergopower levers, the resulting shifting will exactly match with Shimano 10-speed cog spacing, not Campagnolo. Which is a net bonus, as Shimano 10-speed wheels and cassettes are far more available and cheaper than the Campagnolo stuff.

BTW: I done this hack many times: match the older Campy derailleurs with Campy 10-speed and Shimano 10-speed cassettes. Works absolutely flawlessly every time.

In that case, let’s hope that some genius in Vicenza 35 years ago didn’t have the idea: „hey…let’s make the cable pull ratio for our mtb shifters different from our road set up…just for the heck of it!“

It is certainly possible that the ratio mismatch of a 10 speed Campagnolo shifter (1.5) with this 8 speed derailleur (1.43) will produce perfect shifting on a Shimano 10 speed cassette. My napkin calculation is that you'd get about 3.92 per shift, which is close enough to Shimano's 3.95 spacing. Don't know if that is worthwhile to you or not.


I missed Dave's post - same information.

It is...and it is much appreciated. I snooped around on the internet and I found an advert from a gentleman in Germany who is selling a long cage Euclid rd currently. In his item description he claims to have used it with Campa 10speed Ergopowers and that it worked very well. So it seems that a) it has indeed a 1.43/1 actuation ratio and that b) the minuscule deviations from the ideal cog spacing with a Shimano cassette are no problem...we'll see. Thanks to everybody chiming in here!

So…

Campy Athena 8 speed or Mirage 9
Plus Campy 10 speed ergos
Plus Shimano 10 speed cassette

Equals happy shifting?

This is very intriguing. Does anyone know how to tell which campy derailleurs have the older pull ratio?

I picked up a nice hyperglide wheeset and have been passively looking for a jtek shift mate so I can run it on my campy 10 speed equipped road bike. But I have a 9 speed chorus rd in the parts bin…I might need to try this out…

I just checked Velobase on the three versions of Euclid; unless I read wrong, all said "friction" although I guess if the math works out the RD doesn't exactly how it is actuated.

BTW, I have one, NOS, pondering how to use it. The pulleys apparently have no sub at all and in my hands, spin almost like one of the fidget sinners. I presume not so in the real world on a bike, after some time in use. looks like loose boll bearings, maybe some kind of chain lube? Grease? Other? I wax my chain, but think waxing derailed pulleys would not work.

Confirmed, as long as the rear derailleurs are indexing models from the years 1991-2000. These have B-tension screws.

All of the 8-speed generation, and the early of the 9-speed generation.

So, Euclid goes back well before the 8 speed era, so it is possible that there is a version that is not 1.43. Syncro derailleurs of that era had slightly different pull ratios, but they were around 2.0 for 6 and 7 speed. Index shifting provided by a Syncro thumb shifter and freewheel, rather than the later Bullet grip shifter and cassette hub.

https://www.disraeligears.co.uk/site..._-_euclid.html

So I guess I'd be surprised if the early version without the barrel adjuster was 8/9 speed index compatible. Reengineering the derailleur for different pull ratios is really just about moving the anchor bolt location, so the basic design could have continued on to the 1990 version. I don't know which you have - got a barrel adjuster?

https://www.disraeligears.co.uk/site...catalogue.html

I checked and... no adjuster. I was hoping I could at least use it in a 7sp application. Sad, because it is in pristine condition.

It might be worth a little experimentation. It might have the 8 speed pull.

Or, if you are adventuresome, adapt another shifter. You can take a set of thumb shifters with a lesser ratio and use a needle file to reduce the diameter of the cable groove until it pulls just the right amount per rear cog position. I did that with a Sachs Rival downtube shifter (1.43 ratio), with a Mavic derailleur (1.7?) until it shifted on Shimano cassette perfectly. You could use Shimano or Suntour 7 speed thumbies.

Or use it with downtube shifters.

As you know, I love these vintage Campy stuff.
I've already used these Euclid RD (without barrel adjuster) to index a Campagnolo 8s and Shimano 8s cassette. FWIK, there is no pull ratio difference if it's with or without barrel adjuster...
And very interestingly, as you may know, you can use these RD to index a 9, 10 or even 11 speed Shimano cassette. You can search the forum for more details on that.

How about index-7? One of my projects could use that. Depending on DT shifter selected, of course.

With an 8 speed shifter you can use the first 7 clicks for 7. Same (or close enough) cassette spacing.

No problem with 7s, these RD were originally designed for 7s !

Campy 7s and 8s cassettes use the same spacing, so you can use either 7s or 8s shifters to index a 7s Campagnolo cassette.

But Campy road 7 speed shifters pull very little cable compared to later 8 speed shifters, if we are talking about down tube shifters or brifters.

Well, they surely pull enough cable to index a 7s cassette, what the OP is asking for . . .

It isn't a problem of how far the lever moves, but how much cable per click. If you use an '80s Syncro 7 speed shifter to shift an 8 speed geometry derailleur, you would only shift across 5 gears before you had used all 7 clicks. That's "pull ratio". We are thinking that this old Euclid has a 1.43 pull ratio, but a 7 speed Syncro shifter is built for around 2.0 ratio.