Super Record chain wrap
 

I've got what I believe is a second generation Campy Super Record rear derailleur, and I'm trying to set it up with a triple crankset. According to the 1982 Campy catalog, the chain wrap capacity for this derailleur ought to be 28. I'm using a 49-42-32 crank and a 13-24 freewheel, so that should work, right? My trouble is, I haven't explored the edges of what Campy derailleurs of this vintage can do, so I'm not sure how short I can get away with cutting my chain. Here's how it looks now with the big-big combo (kindly disregard my phone's choice of what to put in focus):

https://live.staticflickr.com/65535/...82cb6ebd_c.jpg

With a modern derailleur geometry that's about as far as I'd want to stretch it out, but it seems like I can keep twisting the derailleur cage to the point where it would effectively allow the chain to go straight from cog to chainring without any deflection. Is it safe to run that way? It looks like I could probably take out two more links if I let it wind that far. Right now, the chain is too slack on the 32-15 combo and 32-13 is out of the question.

(FWIW, I am aware I could make this a non-issue with a long cage swap, but those are ugly and I'd like to keep this bike looking good.)

Thanks for any help!

JMO of course but I'd say that you're wasting your time with a wide range triple and a short cage. No matter how you cut it you will gain no gears ultimately. Use two rings and get a 7-gear cluster/freewheel and be happier

Like I said - JMO

In the lingo of the day, 28t max meant the biggest possible cog you might get away with on your freewheel, not total tooth capacity.

Honestly, that looks dangerous. A chain that short could fold the rear derailleur into your wheel. You'd be better off adding some chain, and losing another gear combo with the 32t. That's kind of a hack though.

I suggest you get one of those SOMA Spence Wolfe style extender cages if you want to run a triple. A super record RD simply is not designed for that. Typical gearing would have been 42/52 and a 13-21 in back. Maybe a 13-24 for those epic climbs or for those that preferred to climb in the saddle most of the time.

I thought about that. I have a 6-speed 13-30 freewheel which, if I could get this derailleur to work with the 30T cog, would provide almost the same range as the setup I'm trying to make work here, but it would obviously have much bigger jumps between cogs. Anyway, I like triples and I like to make weird combinations work. Wasting my time is one of my specialties. :D

Hey Andy.... Dean in Port Angeles here! I can't offer much help in the extremes to which a Campy SR RD can accommodate other than to tell you that I ran one with 52-41 chainrings and a 13-26 freewheel on my Cooper. Old legs and hills I like to ride were driving me to a 32 tooth cog in the rear. As I recall, I could not get the SR to clear the 32 even with the rear axle located at the rear of the dropouts of my Cooper. I don't recall anything about the chain wrap. I went down the path of the Soma long cage swap. It worked, but I totally agree with you that it did not look right. In the end, I chose to replace the SR RD with a Suntour Cyclone GT with a black hanger. In my view, it looks much like the Campy RD, handles the 32 with ease, and shifts great. The SR RD is boxed up....safekeeping for a future owner.

'Hope to see you again someday on the north end of the Olympic Peninsula!

Dean

That makes sense. I see now that the catalog actually lists it as "teeth capacity" so that would seem to fit what you're saying. VeloBase claims a 26T wrap capacity for the Super Record and Nuovo record and claims "confirmed" for the NR. I'd be happy to give up the small-small gear, and really even one more. I don't intend to use those combinations, but once I've been in the granny ring for any length of time my brain shuts down for a while, so I want to make it as close to OK as I can get.

When you wrap that 'railer in a knot trying to hump a 30 you'll suddenly have plenty of time available to waste

One of the luxuries of having a ridiculous number of bikes is that I can have a few like this that are suboptimal in some respect. My goal here is to get the gearing low enough that this will be comfortable to ride on rolling hills. I'm a terrible climber (heavy and weak) so this wouldn't cut it in your neck of the woods, but it'll do for most of the hills in my local area.

BTW, here's why I have to keep it all Campy:

https://live.staticflickr.com/7870/4...5fe79bab_b.jpg

Even the triple is blasphemous enough.

Right! That's why I'm trying to use it with a 24. :innocent:

https://live.staticflickr.com/7870/4...5fe79bab_b.jpg

I'm thinkin' that you are in need of a proper beating with a stout cane

A triple is not blasphemous it is a desecration

Even posing such a thing speaks to a sub-humanity that is in itself offensive beyond telling

​​​​​​​My God, Man!!! What Are You Thinking? ? ? ?

Andy, I’ve used 34-28 on a Super Record RD, but agree with others that pushing bigger than a 28 wouldn’t make for a happy derailleur. If you want to cheat a little with a modern, but looks vintage compact double, and you’re feeling spendy, Boulder Bike has IRD 46-30 cranks for a pretty good price. It’s a really nice crank (put one on my/your Heron re-do).

When you say you used a 34-28, what were the other extremes? 50-34 + 14-28?

I don't know how I stumbled into this insinuation that I'm trying to use something bigger than a 28. The big cog on the freewheel I'm trying to use is only 24. The 32 I mentioned is a front chainring. To be honest, I could probably just block off the big chainring and use this as a 42-32 double. I just want to make the full triple work.

Me trying to make this work:

https://i.imgur.com/tLHcIR1.jpg

I think I've got it working, mostly. I'll post some pictures in the next couple of days.

On my Medici with a Super Record 2nd generation RD I am running a 52/42 front chain ring set up with a 5 speed freewheel that has a 28 tooth low. With the axle stops backed out so the axel is well back on the drop outs it clears the cogs well and shifts fine . I can run big to big if I want , but rarely do.

I am not exactly a conformist.:rolleyes:
You said it yourself...


If you have enough bikes, then why consign this one, an icon of steel cycling, to such a build. It's your right, of course, but just because you can...
Best regards, Eric

It was a 48-34 : 13-28. Yeah I guess when you're done with this experiment you can publish some peer reviewed chain wrap data for the SR RD.

I've used a Nuovo Record RD with a 13-28 and a 35/46.
I've also used a Zeus Superchronos, which is basically a Super Record clone, with a 13-30 and 35/48.

Both were tight, especially the Zeus setup, but I could use every gear.

Because I want to be able to ride it more! Would it not be more of a desecration to leave this bike hanging in my garage unused?

The way I see it, if God had not wanted us to use triples, He would not have made 74 BCD Campagnolo chainrings.

https://live.staticflickr.com/65535/...7850306e_c.jpg

It's not like I'm putting brifters on this or something. From 25 feet away, you probably wouldn't even notice, and that's the point of why I'm doing this the way I am.

I'm having trouble getting my head wrapped around this, unless the Zeus wasn't quite an exact copy of the SR. After I took a link out, I had to slide the wheel forward just a bit to get it to shift onto the big cog when on the big ring. Once it was on it would be fine, but the extra stretch to get over the teeth felt very risky. So this is definitely the shortest chain I can safely use. With this combination, I suppose the small-small combination is technically usable, but it has a lock of slack in the chain. I would report the SR wrap capacity as 26, as VeloBase claims.

VeloBase also says the NR capacity is 26, which matches what you report there, but you got 30 tooth wrap out of the Superchronos. That surprises me.

Submitted for peer review... ;)

With my current chain length I get a little resistance here:

https://live.staticflickr.com/65535/...acb33103_c.jpg

With the wheel further back it was enough resistance that I wasn't comfortable with it. With the wheel where I have it, I can feel the spot but it clears the cog teeth with some room to pivot still left in the derailleur. Since I don't intend to use this combination, I just need to avoid catastrophic failure. (And, I've got some experience with the results of a chain that's too short, so I do know how catastrophic the failure is and how quickly it happens.)

Once the chain is on the big-big combo, it looks like this:

https://live.staticflickr.com/65535/...4d344a1c_c.jpg

Obverse:

https://live.staticflickr.com/65535/...91690b9b_c.jpg

Not pretty, but I have not exceeded the derailleur's natural range of motion.

Small-small is not so good:

https://live.staticflickr.com/65535/...f59bfe78_c.jpg

As soon as I start turning the pedals, it takes up the slack in the upper part of the chain, lifting it off the chainring, but when the pedals aren't turning I get the above result. I'd need 28T wrap capacity to make that work, so I'd judge that the Super Record derailleur does not have 28T capacity.

On the 32-15 combination, the results are much better:

https://live.staticflickr.com/65535/...7eb66242_c.jpg

So, that's 26T wrap capacity (49-32 + 24-15).

Finally, the finished product:

https://live.staticflickr.com/65535/...d3062035_b.jpg

I'd rank the offenses to tradition that I have inflicted on this bike like this:

1. Clipless pedals
2. Modern compact handlebars
3. Non-coil cable housing at the rear derailleur
4. Absurdly long valve stems
5. Tall stem
6. Triplized crankset
7. Modern clincher rims, polished silver not dark anodized
8. Brake cables too long
9. Not period correct bottle cage
10. Quick link in the chain

Others may, of course, order this list differently or spot things I've overlooked.

Fair enough, all 3 are valid points. Ride safe, and enjoy it!
Cheers, Eric

Nice backdrop to a beautiful bike. It looks good in Campy.

Well done!

You, being the sensible and experienced rider that you are, are never going to use small-small, so that scenario is academic.

You will also never use big-big, for the same reason.

But, should you temporarily lapse into insanity, you’ve configured things such that the lesser of two evils will happen:

• A bit of extra slack in small-small, which isn’t nearly as damaging as
• Too little chain in big-big, which will quickly break something that’s vital

Bike looks awesome!

We also have god-given long and mid cage derailleurs, very nice modern and retro models. Isn't the derailleur pretty noisy when pedaling the big ring no matter what rear cog is chosen? That's what I found when I attempted to force a short cage into a triple configuration.

edit: Ah, I just read more closely and saw your big and small rings are 49/32. That's less range than what I was attempting. Still. I'd just use a mid or long cage.

Thanks!

I wouldn't bet that I will "never" use the bad combinations, but it will be rare. As you say, I'm basically trying to make sure that my response to accidentally using the bad combo is "Oh yeah..." rather than "Oh no!!!"

It's noisy on the big cog, but the rest of the cogs are fine. Also, the SR front derailleur shifts the triple amazingly well with this set of chainrings. I've found that a Nuovo Record front derailleur is absolutely terrible with a 52-42-24 crankset. It wouldn't shift from the small ring to the middle -- I had to shift from the small ring to the big ring and then back down to the middle. (I won't even dare show this crowd the bike that has that! :eek: Suffice to say I wanted to at least have a chance of climbing the hills at California Eroica.) I had heard that a 49T big ring is the secret to making the NR work with a triple. A bigger granny gear probably wouldn't hurt either. With the 49-42-32 rings, the Super Record shifts as well as if it were designed for this.