Crosse531

I want to replace my TA crank with a campy on my 1970 Motobecane Grand Record . Will the campy fit the spindle?

Barrettscv 

Welcome to Bikeforums! Yes, European-made square-taper cranks and bottom brackets use the ISO dimensions.
ISO models include:

Campagnolo
Older Stronglight
Nervar
TA

My Grand Record came with a 118mm bottom bracket spindle that should accept the Campagnolo crankset.

Personally I like the TA Professional that is original on the Grand Record more than a Campagnolo Record crankset of the same era.

juvela

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+1

looks great and it goes down to a 36T inner instead of a 41T (assuming the 144BCD).

since it is bare metal it can be polished.

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John E

The TA Professional looks great and does go down to 36T, but it is less rigid and less robust than the Campagnolo -- there was a reason for the larger BCD and the 5-bolt spider. A coworker at the bike shop sold me the TA Professional from his Lejuene bike because he had needed to replace at least one chainring due to bending. The crankset served my wife well for a number of years, but I would have reservations about using it with a large rider who is also a gear-masher.

I eventually swapped in a pair of Sugino cranks because I have a collection of 144mm BCD chainrings and because I wanted to change to 165mm cranks to reduce toe-to-tire overlap, but I kept the TA spindle in the UO-8's bottom bracket. Works like a champ.

Salamandrine 

The general consensus these days is that TA is actually closer to JIS than ISO. IOW a campy crank will sit out a bit farther.

In a certain sense they are all compatible, because the taper angle is the same. ISO and JIS are new inventions. Reality is that it's a continuum. In olden days we'd often try and fit if it wasn't a known combination - ie campy crank with correct campy BB.

For an old gran record I'd personally leave it alone. Why do you want to change it? BTW I agree with John E above. I am a biggish dude and could easily flex them BITD. Even so, I would leave it alone for that particular bike. Spin more, stomp less.

63rickert

It depends. Probably not. Which Campy crank are we talking about? An old Campy 1049 double would usually need a T.A. triple spindle. But even that rule has all kinds of exceptions. Your other choice would be an old Stronglight 49D, which fits just the same as T.A.

What flexed on T.A. was the chainrings. There are all kinds of workarounds for that. Too many fast rides and races done by big riders on T.A. to dismiss them as hopelessly flexy.

T.A. cranks were available in a huge range of lengths. The odd lengths were machined down from oversize blanks and did break. The 170 crank had its own die and was plenty strong.

big chainring 

I'll support the change to Campy. I love French bikes and components but the French are notorious for soft metals. Even their surgical steel is soft. Go with the Campy.

63rickert

Gotta agree with big chainring about softness. I really like French cranks but...
Lately I am mostly on new production T.A. rings that are supposed to be 7075 aluminum. No way are they as hard as a Campy ring. The old ones are just plain soft. And some softer than others. One marker that seems to sorta work is to check the "T.A." stamp. If it stamped deep that ring is soft. If the imprint didn't quite take that might be harder metal. In any case if you use French rings keep your chain clean and lubricated. Curious if anyone knows how hard the new Sun rings are.

The next step is to get vintage steel rings. Plenty were made that will fit.

clubman 

The adapteur models were even stronger with the extra webbing. I've ridden two of these for many years as a Clyde and never experienced any excessive front chain rub compared to other marques. Nor have I replaced many rings. I think there's a fallacy somewhere here.

steelbikeguy

are you referring to SunXCD rings?
I've got a set of their TA Cyclotouriste clone crank arms, purchased from Velo Duo, but they came with the modern Pro 5 Vis rings from T.A. Only ridden them once, so can't comment on hardness. Do SunXCD make rings? Do they make the rings that Velo Orange is selling?

I will say that I've been using some of T.A.'s 110 BCD rings for many years, and hadn't noticed any problem with hardness. Come to think of it, I've also been using their 144mm BCD 41 tooth rings on Campy cranks, and they've been just fine.

Steve in Peoria

63rickert

Hi steelbikeguy
I can believe your T.A. rings are doing well. The best I am running at the moment is an old Criterium outer that has a lot of miles on my fixed gear Rivetts. I've shark toothed a rear sprocket and had a couple chains on there and that ring is still going strong. That ring was free too.

OTOH the ref.203 outer ring on the Bates only has a few hundred miles and looks sad. The '7075' rings on the Carré might have 1500-2000 mikes and are ready to be replaced. My wife is pretty quick for a 68 year old lady but she only weighs 103# and she is wearing down her T.A. rings pretty quick. She had a 42T triplizer by T.A. and did that in quickly.

I really like French. All 5 in service road bikes in the house have at least one T.A. ring at the moment. But if reliability and longevity matter it's Campy. If longevity really matters then you want Nuovo Record and not some other Campy.

El Chaba

To say that French metals are soft is a gross oversimplification at best and an incredible inaccuracy at worst. I have several TA cranks and chainrings on various bikes and have found them to be nothing but reliable and durable. As for Stronglight, while I have found their rings and cranks to be quite durable, the zicral rings that they have made over the years for various models are the most durable rings that I have ever encountered.

big chainring 

Ah oui, oui. Let the French make the cheese, the bread, cassoulet, confit.

I say why stop at the cranks? Its a Grand RECORD. Go all in with Campy NR seatpost, brakes, hubs. Its the era of the groupo, gruppo, groupset. No frankenbikes allowed.

JohnDThompson 

When I was with Trek many years ago, we did hardness testing on a variety of chainrings. Stronglight were the hardest, closely followed by Campagnolo. Japanese rings (Shimano, Sugino, Sakae Ringyo) were next, and all pretty close to each other. TA were the softest.

But my experience with recent TA rings suggests that they are made from a harder alloy than they used back in the 80s, although I can offer no empirical data to support that.

El Chaba

This makes a lot of sense to me. Most of my experience with TA rings has been with recent production, and they are good. I have one older TA crankset-a pro vis 5- that I can swap onto my randonneur bike if need be, but it is normally set up with a TA Alize double. The various French makers tended to put a fair amount of thought into their designs and execution, so I wonder if the older TA rings were softer alloy because the outer ring did double duty as a spider and the softer material was less inclined to crack....
I always felt that the Japanese alloys were soft, and not just the chainrings.

Salamandrine 

7000 series alloys were invented in Japan. These are considered the best for chainrings. It's a mistake to attribute metal hardness to national origin. All the aluminum alloys and tempers have international standards. I guess it's possible for some manufacturers to fudge the temper. There's probably much more variation at the low end of things - "melt forged" components and all.

Does TA still make its own chainrings? I was looking at a TA Carmina crankset originally for my Mercian, but I couldn't justify the cost. I've heard those are made by Sugino under contract.

Re the OP - an easy way to stiffen up a TA crank would be to use a modern beefed up outer chainring, like the ones VO sells. If that is in fact the issue. I've always found crank flex to be rather trivial compared to frame flex anyway.

Also I wasn't clear on spindle length. My point was a campy crank will sit out farther on a JIS spindle than a ISO spindle. But, they require a longer spindle than TA to begin with, so in fact the original TA may not be long enough. Best to consult Sutherlands. The advice of 63rickert that a TA triple spindle will work sounds right, but it's been so long since I've worked on TA stuff regularly I don't remember. If you really insist on using a campy crank, I'd swap out the BB for a campy too. It will work for sure, if you can find one.

steelbikeguy

If Peter White's site is any indication, T.A. is staying fairly busy offering chainrings for just about any configuration imaginable, including the Pro 5 Vis rings and the 144mm BCD rings for our vintage curiosities.
https://www.peterwhitecycles.com/ta-chainrings.php

Granted, they aren't cheap. On a dollars per mile basis, I'd guess that they are competitive with the less expensive Sugino rings (which I've also got on a couple of bikes).


Steve in Peoria

fietsbob

Quote your historical references? ... or just repeating hearsay?

7000 series indicates a Zinc Content in an aluminum alloy (except 7050)

Machinery's Handbook pg 604 lists 8 alloys in 7000 series..

numbers other than zero indicate other elements added to the Alloy.




....

Salamandrine 

Dude, look it up. It's common knowledge. Developed in the 1930s by Sumitomo for aircraft use. Probably read about it one of my materials books first. Books are those things made of paper.

El Chaba

Regardless, there is no way that the Sugino, SR, or Shimano chainrings from the 70's-90's were made from 7000 series alloys. Just my seat of the pants observation was that a Sugino Mighty chainring-144 BCD and often used as a low cost replacement for a Campag NR or SR - had about half the useful life of an original Campag.

fietsbob

You may find putting a Campag Crank on the TA spindle fits but it will sit further out from the frame..


from Old <C> catalog #17 [1974], road 68-ss-120 (5 speed) is 112mm long overall, triple 68-ss-120x3 is 117 long..