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Technical Q&A with Lennard Zinn - Going retro'

Published: Jun. 23, 2009
When Nuovo Record was ... well, <em>nuovo</em>.
When Nuovo Record was ... well, nuovo.
Photo: Agence France Presse - file photo

Dear Readers,
Yesterday having been my 51st birthday, I figured I’d do a retro column. Fortunately, it’s not hard to sort through the VeloQnA inbox and find plenty of emails that raise questions about retro equipment.
Lennard

Dear Lennard,
Is the threading on the Campy Nuovo Record rear derailleur mounting bolt a different size than the Campy Victory?

I'm rebuilding a mid 80s Trek 760 with some Super Record & Nuovo Record components and the rear derailleur appears to not want to thread onto the dropout (the Victory derailleur that came with the bike threads in just fine). I don't want to see metal shavings coming out of the dropout after applying pressure to the bolt, so I thought you'd be the person to consult.
Bill

Dear Bill,
Geez, I sure don’t think so. I think I’ve maybe put on one Victory rear derailleur in my life if that, but I certainly don’t recall that they could not be mounted on a standard derailleur hanger.

I’ve put on oodles of Super Record and Nuovo Record derailleurs in my day, and they always fit a normal rear derailleur hanger. And I can’t imagine any mid-1980s Trek not fitting a Nuovo Record rear derailleur. So I think the bolt on your Nuovo Record rear derailleur must be damaged.
Lennard

Dear Lennard,
Again I must consult your expansive knowledge and check with you regarding my latest acquisition: a '76 era Raleigh Team Record.

While overhauling the front hubs, I noted eight ball bearings in one side of the shell. It looked like it was missing a ball bearing, there seemed too much space. I checked my ball bearing collection and added a similar diameter bearing to the set, put them in a separate bag, and turned my attention to the other side. I was again confronted with eight bearings in the hub shell. I tried dry-fitting nine bearings into the shell and inserted the cone. Seemed OK, but I wasn't certain about it.

So, Lennard, the question is eight bearings, which is what I found in them, or nine to a side? What's your experience with 70's Campy front hub bearings?
Bill

Dear Bill,
My experience with 1970s Campagnolo hub bearings is that they always had nine bearings. I have heard of people taking one out in hopes of it rolling faster by each ball drag less on its neighbors, since their surfaces are going in opposite directions. Maybe that’s what the previous owner did with your hub.
Lennard

Dear Lennard,
I have a mid 80's Columbus steel frame made by Dave Moulton with a Campy Nuovo Record group. I have had problems with an "auto shift" every once in awhile - usually during a climb the chain will jump from say first to second gear. Will worn derailleur pulleys cause this or is my 1983 derailleur weakening?
Dan

Dear Dan,
I would guess that one of three things, or a combination of them, is happening.

One cause could be flex in your chainstays causing the bike to autoshift as the chainline changes by virtue of the dropouts moving laterally inboard out of the plane of the front triangle. This will cause the chain to drop to a smaller cog.

Another cause with a derailleur like this is that the frictional shift lever is slipping. Tighten the lever screw, or take it apart, clean up the parts, and put it back together, cinching it up sufficiently to keep the lever from slipping back in response to the cable pull.

Another could be worn pivots in the rear derailleur making it sloppy and loose and unable to control the chain closely. Worn pulleys could play a role as well, yes.
Lennard

Dear Lennard,
I have an older steel trek with all Campy Nuovo Record components. I recently did maintenance on the rear derailleur including new cable, housing and general clean up.

After replacing everything I find the shifting to be overly sensitive and it now takes a lot of adjustment to seat the chain completely. The adjustment is usually a longer throw than the movement required to shift initially. As all of the repair books/manuals document Ergopower and STI, and have no coverage of older derailleurs do you have any suggestions as to what the problem may be?
Marty

Dear Marty,
I think you have too much friction in your cables, even though you just replaced them. Perhaps you put a tight bend in the housing to the rear derailleur? Those derailleurs originally came with an unlined steel coil housing there within which the cable did not slide particularly well. If you did not already, you should replace that with a piece of lined derailleur cable housing. Clean and grease the cable guides at your bottom bracket, too.

Another cause can be a worn chain that is laterally too floppy to move over a cog when the derailleur pushes on it.

Another possibility is that the chain is too long so the gap between the upper jockey wheel and the cogs is too large.
Lennard

Dear Lennard,
I am interested in competing in time trial whose rules are classified as “Cannibal,” meaning that the equipment is the traditional non-aero stuff that riders used before the mid-1980s. Basically, the rules prevent you from using discs, aero’ bars, deep section rims and all the fancy do-dads that people now think is essential.

Are there any accepted norms for this type of event, frames, wheels, etc?
David

Dear David,
The “Cannibal” rules would be what I’ve often heard called the “Merckx” rules (Eddy Merckx was known as “The Cannibal” during his racing days, due to his endless desire to win and figuratively consume other riders along the way).

Since you won’t find this in the UCI rulebook, I think it is up to individual race promoters.

For example, here in Boulder, Clark Sheehan puts on a time trial series that has a “Merckx Class.” The understanding is generally that it should be on a bike like Merckx would have ridden, much as the new UCI rules on the world hour record on the track are meant to ensure that new records will be directly comparable to what Merckx did when setting his hour record that held up until Francesco Moser notched it up using disc wheels, cowhorn bars and short head tube. I guess you could approach it with the question “What would Eddy do?” at the back of your mind when choosing your equipment.

Despite the general restrictions, I’m certain that Clark won’t force you to wear a wool jersey and shorts. The idea is to eliminate aero’ bikes, aero’ handlebars, aero’ wheels and aero’ helmets. I imagine a skinsuit might get you kicked out of the Merckx class.

While disc or deep-section wheels would be disallowed, low-profile rims with a V-section will probably pass. And a carbon frame and STI or Ergopower levers and bib shorts are probably okay, too. You’ll already have to wear an ANSI-approved helmet, which Merckx did not. The idea is to just use a standard road setup, like you would use in a mass-start road race, except with the lowest-profile wheels you have in your garage.
Lennard

Feedback on June 16 column

Dear Lennard,
After reading the letter from Rich to Lennard we would be more inclined to offer instruction on re-gluing and re-mounting the tire. The fact that he pointed out a noticeable raised section of tire, directly over the valve area, in combination with the fact that he admitted that this was maiden voyage with gluing tubular tires, leads us to believe that the tire is not actually adhered to the tire bed surface in this area, and causing the bump as he rolls over it on each rotation. If he were to merely add some rotating counterweight to the opposite surface of the rim, he will most likely still feel the hop at downhill speeds, and associate it with an out of balance situation, which he will chase around in futility. There is always the off chance that this is an anomaly which was not molded correctly, and truly may require some sort of counterweight, but in our experience this is less than 0.1-percent occurrence on standard production 404’s.
Andy Paskins
Zipp Speed Weaponry Marketing Manager

Technical writer Lennard Zinn is a frame builder (www.zinncycles.com), a former U.S. national team rider and author of numerous books on bikes and bike maintenance including the pair of successful maintenance guides "Zinn and the Art of Mountain Bike Maintenance" - now available also on DVD, and "Zinn and the Art of Road Bike Maintenance," as well as "Zinn and the Art of Triathlon Bikes" and "Zinn's Cycling Primer: Maintenance Tips and Skill Building for Cyclists."

Zinn's regular column is devoted to addressing readers' technical questions about bikes, their care and feeding and how we as riders can use them as comfortably and efficiently as possible. Readers can send brief technical questions directly to Zinn. Zinn's column appears here each Tuesday.