Mr. Spadoni 

Got a build coming up ( thanks MadHonk) that seems like the place I ought to use a Campy NR crankset that has been sitting in a drawer. Issue is that with NR I can only go to 42. Could go lower than the usual 28 rear, but that would mean that I can’t use the NR rear that is currently keeping the crank company.
Soma has a long cage to fit NR, photo below. Anybody ever use one of these?

Kontact 

I installed them on a customer's bike, who immediately flew to Europe and did some big eroica with it. I thought they installed and worked well. It isn't a complicated concept.

kroozer 

I have been using one on a NR RD for several years, it works fine. Right now it's shifting a combo of 38-52 chainrings with a 14-34 freewheel, and I think it could handle more. The first Rally derailleurs were basically NR's with long cages. The Some cages look like an exact copy of the Rally cage.

bulgie 

The Soma cages are great. Never tried 'em but I've put Ralley cages on NR for decades, always does the trick. Soma are a faithful reproduction of the Rally, except slightly longer than the '70s Rally (being based on the final version of the Rally, the one that looks like a totally different mech, without the iconic Zamak cast upper knuckle). But I digress; the important thing is they work, look nice, and are dead simple to install. And unless you get really lucky at a swap meet or some such, the Soma will also be cheaper than a real vintage Rally cage.

For getting knee-friendly gears with a Campy NR-era drivetrain, don't forget the Jon Vara "Red Clover" triplizer chainring. You'll need a Record triple bottom bracket (or equivalent length from certain other brands) and a 74 mm BCD granny gear. The Soma cage will wrap up that amount of extra chain, no problem.

Kontact 

Real C&V riders would do all their climbing with a 13-21 freewheel.

bulgie 

In that case I am oh-so-happy to not be "real". If I had been that real back when I was racing and transcontinental touring, I wouldn't have any knees left.

bulgie 

Maybe I'm quibbling but I would call them very different from the NR, since the Rally had a sprung upper pivot. With two sprung pivots to the NR's one, the rally gained extra gear range capability even if you put a NR short cage on it.

My early Rally with a SR (2nd style) short cage on it happily shifts to a 31t sprocket. Not the max it can do, it's just the max a Regina Oro can do (they didn't make cogs bigger than 31t). That's with a 41-50 in front (9 teeth), again not the max it can do, I don't know what the max is. It's not straining in big-big or sagging in small-small. An NR can't do that.

For a Rally that's truly like an NR, with no spring in the upper pivot, you have to go to the third version of the Rally. That was a real step backwards, in quality and price too, since it was based on the GS not the NR, with markedly cheaper hardware and finish. A low point in Campy's always-half-assed attention to the touring market.

top506

Works fine.

Top

Mr. Spadoni 

Ah yes, but I am applying the Rule of 100 here: when the combined age of the bike and the rider is 100 or greater, no justification of route or equipment is necessary.

52telecaster

I've used em too. If you don't mind a campy derailleur, you won't mind the cage.

Mr. Spadoni 

Did you order them for the customer? Via Merry Sales? If I get these, I wanna try to get them from my LBS. The less complicated my unusual requests are, the happier they are to see me.

Kontact 

My customer brought them in. He didn't ask us to, but we didn't order from Merry Sales very often.

LBS's appreciate your patronage, but ordering stuff from places they normally don't cuts the potential profit of the sale down considerably. So don't feel bad just ordering direct.

There's a discountable set on Ebay right now, too.

gaucho777 

I am using a Soma long cage on my Super Record-equipped Colnago Super with a Red Clover triplizer. Works great, maybe a touch more sluggish feel compared to the short cage but overall I’m very happy with it.

I am surprised to see @kroozer and some others getting such large cog capacity with the NR derailleur & Soma cage. My understanding was that the long cage simply adds additional chain wrap, but doesn’t really change the position of the upper pulley, or by extension the max rear cog capacity​​​​​​?

I believe my setup is 13-28 x 52-42-30.

Kontact 

"The Campagnolo compatible cage plates allow you to run up to a 32 tooth cog in the rear,"

You can see in your pictures how large the gap is between the bottom of your low 28t cog and the top of the upper pulley. The new cage isn't just long, it relocates the upper pulley a lot lower and toward the rear than the factory short cage does.

bulgie 

I see a lot of people using the Soma cages in a way that seems wrong to me, too little chain. A longer chain would rotate the cage clockwise, which would tighten up the gap, i.e. raise the jockey pulley to be closer to the freewheel for better shifting. Of course it's possible they needed that extra gap to get to the very large sprocket, but I think at least some of the setups I've seen would work better with at least one more link of chain.

Kontact 

It depends if they are using HG style cogs or not. HG shifts so well that bigger gaps make it easier to avoid chain noise. But with vintage style freewheel cogs running closer would be better.

However, on gaucho777's bike, the granny is pretty small and the photos are in the middle ring. So I'll bet that pulley gets pretty close to his 28t when the granny makes all that extra slack.

gaucho777 

Hoping this isn’t too tangential from the OP’s intent, but this made me curious enough to peek down the rabbit hole. It does appear there is enough room in my granny (currently 30x28) to squeeze in a slightly larger rear FW. For reference, I took a few photos of my setup in high, low, and cross-chain iterations

I typically set my chain length by starting in small chainring and small cog and removing just enough links to remove chain slack. As you can see, there is no way to remove another link without the chain interfering with the upper pulley in the small chain ring to small cog set up, but the chain is still taught. I probably could remove one more link, but I’m never in that cross chain gear and I’d rather it not be tight in the large large combo. As it is, it really doesn’t want to go into that cross chain gear on the big big end.

Sidenote: I did remove the dropout screws and pull the wheel all the way back to accommodate the large 30mm tubulars. YMMV depending on wheel in dropout placement.


53x13


30x13


53x28


30x28

dddd

Really clear to see what's going on gap-wise with your four photos!


I always liked how the dual-sprung rear derailers helped maintain a more consistent chain gap, all else seeming equal.

bulgie 

Looks optimized, thanks for the pics.

Kontact 

gaucho777, I wouldn't shorten that chain. Looks like it is working about as close to "design" as possible.

Kontact 

For those just running wider gearing that is within the wrap capacity of the derailleur, you can also just put something under the tab on the hanger to simulate tightening the B screw. For a steel from, those tiny rare earth magnets would work great. With a 14-28 freewheel they would work really well, but you could probably get out to 32 without too much trouble. Especially if you ran the chain slightly too long for small/small.