Supernova89

Hopefully this is the appropriate forum!

Hi all... New to the forums and somewhat to road biking in general, I've always used whatever was laying around. I recently got my hands on what I believe is a 1998 Bianchi Campione D'Italia (Can't find the year or specifics on frame, but it looks just like this bike: 1998 Bianchi Campione - BikePedia).

The condition is decent enough that I think I can put in the work and bring it back to a pretty nice state.

Aside from cleaning junk and rust, really the only serious issues are:
-Broken wheel spoke
-Bent derailleur hanger
-Bent/cracked rear derailleur

The current issue I am facing is trying to find a replacement for the cracked rear derailleur. The bike has a complete Campagnolo Mirage (8 Speed) groupset, which I realize is dated an out of service nowadays. I've seen elsewhere that I can use a pre-2000 9 or 10 speed in place of the really hard to find Mirage 8-Speed derailleur, but I would love to confirm that specifically here.

I saw a 9-Sp Campy Xenon for a good deal, would that do the trick? Is there anything else I should be aware of if using a 9/10Sp derailleur on an otherwise 8 Speed groupset?

I think this bike could be really beautiful with a little work.. Thoughts? Thanks for the help!

Road Fan

I have that Mirage group on a 1997 Italian-made Georgena Terry bicycle that Mrs. Road Fan rides, and the 8 speed Campy indexing is still working perfectly. With the damage you describe, I think the bike fell or was hit. It's not like the Campy parts, even Mirage, have a service life of X years, after which you should replace.

You can certainly find another 8-speed Campy rear derailleur on Ebay, and with some help here perhaps find out if it has the correct cage length. Don't toss our your broken one, it may have some useful parts, and you should visually compare any new one to your old one. Aside from color, some material upgrades or the model name on the side, they should visually match closely. You should match the cage length of your broken one. You can also buy a higher level of Campy, such as Chorus or Record, if it's affordable.

You really need to get your frame dropout fixed and the spoke replaced.

Overall while this repair has a few critical elements, it really isn't a worst-case scenario, and you'll have a great bike when it's done.

Road Fan

Just looked on Ebay: there's not much, as you said, in Mirage 8-speed. But there is a lot if you search for Campagnolo 8-speed, which looks at all levels of Campy parts, from the top of the range Record or C-record all the way down to Mirage. You need to know your cage length and how it is described. with some pictures and if you can describe the gearing, many folks here can help you with that. If you really need to clarify the compatibility between 8, 9, and 10 speed parts, look on the Paceline Forum (not part of Bike Forums) and send a message to "Old Potatoe" - one of the great experts, and a helpful gentleman!

gfk_velo

The rear gear that you need will have a screw where Shimano place one, at the point where the top pivot bolt meets the gear hanger. Later rear derailleurs where this screw is absent (or, more accurately, a screw doing the same job is present but placed on the derailleur cage itself ...), won't index correctly with your existing levers as the geometry of the rear gear was changed in 2000/2001. Record and Chorus 10s never had this screw, nor did any other 10s rear derailleur - Record and Chorus went 10s in 2000, the other models changed design in 2001. Even the 9s rear gears after 2001 had the new geometry and a change in the cable coiling bushing inside the lever was made to accommodate the new geometry.

vinfix

You should be able to find a Veloce 8 speed RD for $40-50 bucks on ebay. I had one for a while, it worked well.

Supernova89

Thanks guys for the input! Sorry for the delayed response. I've added a few pics to hopefully clarify things a bit.

The bike itself:


The old derailleur, cogs removed:



Is that a medium cage? From what I gather the rear cogs are 12-23 which would fit a small cage (double sprocket).. should I be looking at mediums or longs for any reason.

After some perusing on eBay for a few days, I really haven't found anything worth grabbing.. I have however found several websites selling Campy 9sp Xenon RDs for around $40. For example, see here.

They look similar design wise so I'd like to grab one if it's a good match.. thoughts? I'm not sure why they are so cheap compared to all the others though.. is Xenon the lowest end or just out of date? Also, if I do pick up this part, am I correct in assuming I also need a thinner 9 sp chain as well?

I'm still a little unclear on the whole 2001 geometry change.. most of what I see for RDs have the same hanger screw on the top pivot arm whether it's 9 10 or 11... I'll have to read up a bit more.

flatlander_48

Other sources might be:

Branford Bike- Lynskey, Focus, custom, Zipp, Enve, HED, Merckx, Calfee, Look, Accessories, Apparel; Seattle/Bellevue Campagnolo Pro Shop

Campyoldy - Vintage Campagnolo and Classic Cycle Equipment

gfk_velo

Most derailleur manufacturers have a "B Screw" at the top of the mech.

Campagnolo had no B screw in any RD from 2001 until 2015, whether 8, 9 or 10s.

Campagnolo changed how they handled that part of derailleur / cassette set-up, putting their equivalent adjustment at the jockey cage in order to allow a wider range of adjustment than is available with the B screw at the top - the problem with a conventional B screw is that the screw has a maximum length - once it passes a certain length, the tip of the screw will no longer bear on the part of the rear hanger that it needs to, to change the tension in the upper pivot spring.

A worm-gear driven mechanism on the end of the lower pivot spring does the same thing (all you are actually doing when you screw the B-Screw type screw in or let it out is changing the balance between the upper and lower pivot spring strengths) and can allow a much wider range of adjustment.



Rear derailleurs that WON'T index correctly with your levers have the H-Screw adjuster like the one shown above. This applies whether they have a B-Screw adjuster (pre 2001 all models, and Chorus, Record & Super Record 2015->, Potenza 2016->) or not (everything else).

Hence, the Xenon RD that is currently available is not compatible with your levers as it has this screw, whilst your current RD, looking at the pictures, does not appear to have it - we can't see the back of the upper part of the RD in your images but I would expect there to be a "B Screw" present.

It was not simply the moving of the B-Screw to the new position that changed in 2001 - the actual ratio that defines the increment of derailleur movement compared to the amount of cable recovered / released in the levers also changed.

Supernova89

Thank you for the detailed explanation GFK. My Mirage RD does indeed have, or had, a B Screw (as you can see in the image below, that screw piece appears to have snapped off in the damage, hence my confusion)



So my options seem to be waiting for a local or eBay sourced used pre-2001 RD that matches.. or perhaps I could try to find a replacement B Screw nut and pick up a new RD gear cage, considering the rest of the RD is still in fine condition?

Is there a name for that bolt which holds the B Screw?