Campagnolo Nuovo Record rear derailleur problems.
 

hey,

so i'm very very close to having this bike all together. I put on the derailleur cables today, and shifted through all of the gears quickly realizing that in the highest gear on the freewheel the rear derailleur top pulley rubs on the top (high) gear. if i pull the derailleur backward there is plenty of space for the derailleur to run smoothly. so i have a few questions. A. is this ok to work around, or is the derailleur too small for the freewheel? B. what is the best work around for this? i was thinking a new derailleur hanger or a stop for the current hanger. anyone have any advice? thanks!

crtten

How big is the largest cog on the freewheel?

the biggest cog is 28 teeth. it's a 6 speed freewheel. the derailleur is from 1972. (not sure if it's a short or medium)

There's no B-screw on those RDs, and the largest cog I recall seeing them used with is a 26t. Do we have anyone on here who knows the capacity for sure?

so it looks like i need a new freewheel?

That's my guess but let's see if someone pipes up that knows the NRs max for sure

A NR will run a 28, no problem, been doing it since the 70s. Make the chain as short as possible to fit the big chainring/large cog. What's a B screw? They have a screw (stop) for low and one for high.

I've run a 28 with a NR rear derailleur. Chain length and position of axle in dropout are fussy - try moving wheel forward or back in dropouts. Vertical drops? Uh oh. Then fuss with +/- a link of chain.

Tom

I don't think wheel position makes any difference, its all chain length. Here's my 69 Raleigh Pro, 14/28 in the rear, my standard setup since 1972:

"YO, B-screw"

Man, now you're talking about something I know nothing about! I don't have a lot of experience with Japanese stuff, I tend to avoid it (like French). Not that there's anything wrong with it, just not my fantasy.

Back in the day, I had a simlar problem and it continued to vex me until I discovered I had installed the inner cage plate upside down during a maintenance session. Doh!

One problem with the Nuovo Record is it will work with a 28 FIVE block much easier than a SIX, reason is the geometry of the mechanism, as it swings farther inboard it swings up, closer to the wheel center. Chain length and if horizontal drops are employed an adjustment of the axle back as noted prior can help. No mention was made of the front chainring difference, but no more than 10 (52/42 for example). Many can get it to work iff the 52x28 is never attempted. Good practice to avoid that anyway, almost always a duplicate of another ratio and too much stress and friction.

The widest range I could get to work without lots of tweaking is 52/42 with a 14-26 freewheel

The NR was rated to 26t AFAIR, SR to 28t (revised inner cage plate shape). You can push it a bit but it takes some tweaking, as noted above.

The NR on my Peugeot is extremely sensitive to wheel position. I tried removing the stops and sliding the wheel all the way back to give more room for fatter tires and it rendered it unrideable. It skipped violently on the smaller two cogs. It seems strange because that actuall gave it more chain wrap, but that's what happened and the only cure I could find was to move the wheel forward.

Oh, ye of little faith... here's my 84 Cinelli, been running a 6-speed/28 for 23 years now!

Shorten The Chain

This is a great thread for me as I have just encountered the same problem. I can barely fit a 26 on there though I am using an 8 speed cassette. Not sure if that makes a difference? The dropouts on my Guerciotti are I guess what you might call semi-horizontal. They slop downward from back to front so I had to set the wheel in as far front in the drop outs as they would go which effectively lowers the cog set from the derailleur hanger.

The other issue I have is the derailleur hitting just barely the spokes when on the 26T cog. This may be attributed to the 8-speed?

Either adjust the stop to keep the derailler from moving into the spokes, or add a spacer behind the freewheel (assuming it is a freewheel).

Hmmm,,,I think he said Cassette, not freewheel,,,

Yea it's a cassette. I grinded down the pulley bolts so that I could have a little more room. I can't adjust the stop any more or else it won't shift to the 26. Perhaps a redish of the wheel? Or maybe I can get away with bending the deraillure hanger a tad. It is just barley plinking on the spokes and only when I torque it while standing for example.

A 1mm spacer behind the cassette would probably solve the problem. You should still have enough threads to secure the lockring. It will move your smallest cog 1mm closer to the dropout. Hopefully that won't cause another problem.

With faith...anything is possible: Here's my Bianchi Trofeo running a 9-speed.....must admit it's an 11/26 though. Don

Not saying it cannot be done, if it is an Ultra6 even easier, if the chainline is off where the freewheel is more outboard from center, easier, basically setting one up with a 28 is stage for trial and error, experience will play a role as to how fast the decisions are made. My experience comes from a bike shop where the result HAD to work, repeatedly, so we were conservative, customers did not like scrunched derailluers, bent dropouts and or chewed up spokes. What risks one takes under a shade tree with only the guy in the mirror to blame is another subject.

Well, sorry, my only experience is over 35 years working on hundreds of Nuovo Record bikes (including all of mine running a 14/28 with a Nuovo Record, easily 10-15 bikes). In my experience (since experience plays a role as you say, and I've only been building them and riding them this way since 1972), make the chain as short as possible, it'll work providing freewheel is properly spaced, wheel correctly dished and dropouts and hanger aligned, all of which I do when assembling a bike, (in my basement by the way, but I do work on my motorcycles out under the shade tree). My 73 chrome Paramount is running a NR rear with a 14/28 AND a triple crank, beautifully. I ain't no accident. There has never been a scrunched derailler, bent dropout and or chewed up spokes on any bike I've ever built, and they HAD to work. Heck, I even ran a 30 tooth freewheel with a Nuovo Record rear on a 2 week tour down the length of the California coast once Now THAT would've ripped the derailler off had I gone into the large/large combo. But I ain't that dumb... and I don't think I've owned an ultra6 in my life!

I'm not trying to get into a pissing contest, but you're saying you've worked in a bike store and can't get it to work, and I'm saying I've been doing it successfully for years on numerous bikes and showing you the evidence. Who has the experience on this topic?