John E

Bike: 1982 Bianchi Campione d'Italia w/ Campag. dropouts, Pat80 NR derailleurs (no rear derailleur angle screw), Shimano 130mm BCD crankset, SunTour 14-26 standard-width 6-speed freewheel

Current gearing (works well): 50-42 / 14-16-18-20-23-26

Experiment: replace 42 w/ 38, run wheel position adjuster screws all the way out

Results: 1) Lousy 38-to-50 upshifts -- need to control very slowly and gingerly; chain almost binds on the inner tab of the derailleur cage; reminds me of when I run a 24T granny with 48-40 on my mountain bike; 42-to-50 works very smoothly and easily
2) chain jingle against inner face of 50T ring when in 14 and even 16 in back; none of this with the 42
3) rear derailleur jockey pulley rubs against 26T cog (no problem w/ the 42; removing an inch of chain, the obvious solution, would make the chain pretty tight in 50/26

Conclusion: That's three strikes, folks. Note how far forward the rear derailleur cage sits -- this mounting angle and the length of the dropout tab are the likely suspects.

My best shot is probably to copy of the gearing on my 1959 Capo: 46-38 / 13-15-17-19-22-25, but with a 26 low. I am also considering one of those derailleur-lowering adapters.

My helmet is off to those of you who have reported really low gearing with Campag. NRs.

Original equipment matched 1982 Campione d'Italia specs. Frame date is late 1981. "Charcoal" color not found in catalog listing.

79pmooney

Or, swallow your pride, make senior Bianchi roll over in his grave and put on Cyclone derailleurs to go with that Suntour FW. I raced a Fuji Pro with 54-42 and 13-whatever 5-speed with zero issues, front or rear. Granted I never went bigger than 23 teeth in back but I have no doubt it would have handled a 26 just fine. (Never tried because in those days I rode and raced New England's hills in insanely high gears.)

smontanaro 

John E What would be wrong with a 48 large ring? Most of us old geezers are never going to use a 50-13. (Maybe you're not an old geezer like me though.)

John E

I have run 50/14, not 13, as a top gear for a long time. 46/13 gives me about the same ratio. 46-38 / 13-25 works nicely on the Capo (Campag. 980 replaces the original 1950s Campag. GS), and with 46T up front and a shorter chain, I should be able to push the Bianchi to 13-26. I strongly suspect 38/26, a 40-inch gear, is about as low as I can go on the Bianchi without a derailleur swap. As you may be able to tell from my lousy photo, it is a very close-coupled frame (I have to deflate the rear tire to remove the wheel) with a very short derailleur tab.

I also agree wholeheartedly with the comment regarding the superiority of SunTour derailleurs, as I can attest through personal experience.

Bianchigirll 

I’m no fan of shimano but I’d look for some late ‘80s Suntour MTB or Deore derailleurs in good shape. A triple FD might help your 50/38 shifting and RD with a spring in the mounting pivot plus a slant parallelogram design will improve rear shifting

Aardwolf

I'm running 52-42 / 13-15-17-19-21-24-28
SunTour Cyclone Mk2 GT + Sunrace 7 speed freewheel in 127 OLD.

And I quite like poodling around in 52/13 on the flat, but then I'm only 63

repechage

To stay in the Campagnolo clan one needs the uncommon slant parallelogram post Rally but sometimes referred to as or early Mtb rear long cage mech.
price of the part could just jettison any sensibility. But Valentino would approve.

Bianchigirll 

Rally came in. Slanted model? I thought Chorus was the first?

79pmooney

My good bike has a Campy Mirage. Sweetest shifting derailleur I've ever ridden. (Friction Superbe) Double sprung slant parallelogram. Bought it used for a fair amount of money years ago and it sat half a decade or more. Put it on and wow! It's getting older and wants the old NR re-build (new bushings, etc) but I'm sure this is far below that standard so I'll have to start over when the play becomes too much.

jonwvara 

I would not call that a failed experiment. Your goal was to test a specific hypothesis: whether a 50-38 front combination would function correctly as a substitute for your previous 50-42. You found that it did not. That's a valid result. An experiment is only a failure if it's inconclusive.

Besides, it's not like failure is a bad thing. I mean, I have enjoyed my life so far.

repechage

Not "officially" that is why I fudged on the name, at various times it was sold as that, or one of the curious named off road groups.
Look good, not light, but nicely finished and they just had plain Campagnolo script identification.
If one is lucky and the item is not well described on ebay, a steal, if described with smart keywords.... expensive.

John E

Update: I think I'll keep toughing it out with the 42/26 low gear, which I have used on most of my road bikes over the past 40-45 years. I know I can accommodate a wider gear range with improved shifting with a slant plano, but the OEM NR derailleurs do look great and appropriate on this bike, and I have had it dialed in for the past 30 years with the 50-42 / 14-16-18-20-23-26 1.5-step, which shifts quite nicely and gives me most of what I want. If I do get desperate for a 10% lower bottom gear, then it's clear that my best path is essentially what I have on the 1959 Capo: 46-38 / 13-15-17-19-22-25, but with 13-15-17-20-23-26 in back, which is what I used on the Peugeot, with a 45-42 half-step up front. (144mm BCD crankset on that one limits my options)