Rabid Koala

I was cleaning my 72 Paramount, the one that has the $5 bike swap meet Campy NR crank spider. I noticed what appeared to be a crack on both sides where the crank arm blends into the spider. I know these are famous (or rather infamous) for this, and I recall reading somewhere if they are not too deep they can be filed or ground out to eliminate the stress of the tearing aluminum.

This particular crank set may be too far gone, but I have another with a miniscule crack. I think that one is still salvageable, but am definitely interested in hearing from those with more knowledge and experience than I have.

Remember, the crank pictured is the worst one. The first photo is viewed from the outside, the second from the inside.

As always, thanks in advance for your advice!

tomacropod

a semi-related quasi-anecdote - there was a bulk lot of 50+ cracked strada cranks on ebay a couple of years ago. Went for next to nothing.

- Joel

lotek 

pretty typical for a campy crank (hope the cycling gods don't
strike me down for that), that particular area is a stress riser
and that is a well documented crack.
I believe that filing the edge so it isn't so sharp relieves it?
do a search of CR archives lots of threads about that.

marty

cudak888 

Are these post-'78 cranks?

-Kurt

hiromian

Crap, can't correct Campy crank crack. Can complain, couldn't continue cycling creatiing crumby criterium casting creepy kunundrum thus circumventing century.

TheOtherGuy

Sounds just like some of the SPAM emails I get...

LWaB

If that is the worst crack, fix it. Grind out the crack, check with a crack penetrant that you are down to uncracked metal, if not, grind again. Round out that region to minimise stress raisers and ride. Done that several times (to different cranks, including a Suntour Superbe but most commonly Campag).

s70rguy

Nostalgic moment! Reminds of my LBS owner, opening a drawer full of those, waiting for warranty replacement.
File out with a rat's tail file, until the crack is gone. in this case the crack seems too long already to do that. Filing out was also done before a crack was there, as preventive measure.

Rabid Koala

No, the one pictured is a 74 and the better one I was referring to has no date stamp so I guess it is pre 72.

Rabid Koala

I figure I have nothing to lose if I try it. I can't ride it this way as I would prefer not to crash when it fails and don't want to sing soprano either......

repechage

Attempt filing it, use a find file, and sand smooth. Might try a chain saw chain file. The very late Super Record cranks changed the way material was distributed at this region. The very very early cranks machined this regional "crack zone" away.

The cranks I have seen first hand that have failed big time failed at or near the pedal hole and at the shield logo, usually with visible localized polishing from toe straps or ankles first.

cyclotoine

interesting, I just checked a bunch of my cranks and see very small cracks on them. The pre 72's look pretty good and savable with a bit of filing. the 84s look smoothed out in that area and okay, the 77's seem to be the worst (and the shortest at 170mm) and I have yet to check the 1980 180mms.

Edit: These are all record crank sets and all different lengths so I was curious to see deiferences.

Rabid Koala

I got a carbide grinding bit for my Dremel today. I will give that a go and polish it out then check for cracks. I don't have any dye for finding the crack, but I likely can improvise with a Sharpie and a little more polishing. I also have one of those jewelers loupe things to get a better look.

I have two other cranksets on bikes. One has very few miles on it and the other one has seen lots of miles.

I am just glad I noticed it before disaster struck.

John E

That is not heresy, just a simple statement of fact. I recently cracked a left Campag. Veloce crank on the shoulder of the spindle eye.

Dr.Deltron

Was that due to wrong crank/spindle combination? Or overtightening?

Also curious...has anybody continued riding above mentioned cracking Campy cranks?
Do they eventually fail at those cracks? Or are the cracks merely cosmetic?

Just wondering, because I have a set w/cracks (not on a bike) and had been hoping to use them eventually.

Thanks for any input in that regard. Dr. D

mswantak

I read the thread title and thought that drinking the Campy Kool-Aid was bad enough, but now you guys had found a way to smoke the stuff, too.

LWaB

One repaired set is still running ten years later, I suppose it'll fail eventually. Everything does, eventually...

John E

Although this is possible, I have been doing all of my own work on numerous bikes with aluminum cotterless cranks since 1971, and this is the first time I have ever cracked a crank at the spindle eye. (In a completely unrelated incident, I once broke a 1970 Sugino crank across the pedal eye during an out-of-saddle climb -- ouch. )

That's about the only rational explanation left. When I mounted the cranks onto a Campagnolo cartridge BB, they did not seat quite as deeply as I would normally expect from past experience with various brands of cotterless cranks, including TA, Stronglight, Nervar, Ofmega, and Sugino. It was the same effect as trying to put a European crank onto a Shimano spindle, but less pronounced. Did Campagnolo ever vary the cutoff size of its 4-sided 2-degree spindle tapers?

---- Dr. John

Rabid Koala

Well, I played around with the Dremel last night. I used a carbide grinding bit. I think I got through the crack, though it needs more cleaning and polishing than I had time for.

I did use the jewelers loupe to look at the cracks, and a that magnification they look like the Grand Canyon. So far, 4 out of my 5 Campy crank sets have the cracks to varying degrees.

Crap.

cuda2k

Looks like my 86-ish Campagnolo S.Record crank has some minor cracks as well. I'll be breaking out the dremel next week to clean them up. I tried to take some photos but being night and having to use the flash they were difficult to see in the photos. Though they don't look nearly as bad as the 70's Strada posted above.

cudak888 

-Kurt

cuda2k

yup, Campy cranks with cracks left and right. I'm going to take a dremel to mine, they don't look as developed as those you have there.

SingleSpeeDemon

cudak888 

^
Two can play that game...



-Kurt

SingleSpeeDemon

I think yours was easier to do than mine.