Otis

I'm trying to find a Campy 9 speed RD, the two I've found so far are cracked in same place. Is this a common occurrence on these? It's not an RD I have much experience with.

I've had lots of the 10 speed RD's over the years and have never had one fail like this..

gomango

Yes, I have two as well.

gaucho777 

Yes, it's a thing. When I was in the market for a 9-speed Campagnolo RD, I learned this was a common fail point. I saw several units on eBay with cracked knuckles "for parts" (and some other sellers claiming there's a crack but it works perfectly :roll eyes: ). I believe Campagnolo learned from this and used a beefier knuckle for later 10-speed RDs. I opted for a 10-speed RD since the medium/long cage 10-speed RDs offer greater cog capacity and are still compatible with later generation 9-speed ergo levers.

delicious

The 8 speed Records tend to crack there as well.

gfk_velo

Well, it's a "thing" in that it does happen, yes.

However - both of these RDs are getting pretty long in the tooth now. Campagnolo (mostly) migrated Chorus from 9 to 10s in Model Year 2000, forged aluminium alloys do have a life and the material does "age" plus unless they are yours from new, you don't really know their history and how they might have been used or abused ... we have examples of 9s alloy gears of the vintage here that are fine, still in use with no issues, we have some that actually are working "OK" but that I'd not actually use because they are starting this failure mode and we have gears here that show pretty much exactly the problem that you describe. Likewise some of the 8s (even older now, of course).

Nothing will keep going forever and that's especially true of products that push the boundaries of what can be done with a material at a price point ... a maker can only look at the expected service life, look at the warranty period and engineer for an acceptable rate of loss during the warranty (hopefully very low indeed) and then accept a probably higher subsequent rate of failure during the remainder of the expected service life.

I was national sales manager for Campagnolo's biggest UK importer when these RDs were current and don't remember any great issue with it then ... I am pretty sure I would remember if it had been a "thing" at the time simply because Campagnolo warranty in those days was little short of tortuous with practically everything having to be returned to Italy for a decision. Age and condition of use are probably the main contributors ...

fietsbob

My old Euclid is fine.

Too light for the abuse they receive?

nesteel 

Sorry, seeing the number of these that crack in the same manner, it's a "thing". Campy did a terrific job making sure they last just long enough....................

gfk_velo

Well, I suppose they could have engineered them differently, used different materials, or maybe added some material, perhaps ignored what was seen as the required cost profile and used a higher-spec, slower ageing alloy and so made them last practically forever, as Stronglight did with the original A9 headset - but eventually, in Stronglight's case, the penny dropped that if you want people to buy new parts occasionally, you have to build in some level of obsolesence, so in the A9, they moved to disposable and quite nasty cartridge bearings from a far superior and fully serviceable needle-roller design.

I wasn't happy because I used the Stronglight headsets in virtually every bike I owned, loving them for the durability of the original design ... but Stronglight were making a commercial decision, not one driven by the very natural wish of the end-user for a close-to ever-lasting product.

If that's a "thing" - well, it's also a part of how manufacturing companies survive. It just makes lousy marketing copy :-D

Does it sometimes happen in these derailleurs, typically after maybe 10 years of use? Yes. Do I seriously expect racing-level components to last that long - no, probably not.

gaucho777 

Other examples from recent ebay listings:



With all respects to gfk_velo, I've seen more such failures than one should expect as normal wear on racing equipment. The knuckle is very thin at the point nearest to the dropout where these cracks invariably begin. It's a fail point that Campagnolo saw to correct with later versions.