Soody

So i've got this campag crank. Not sure what it is.
The campag bottom bracket is asymetrical.
32mm on one side. 28mm on the other.
The spindle is ~114.5
The spindle is badly pitted so I want to replace it.

Fitting the crank on the campag taper, it goes on 11mm. And there is a clear mark where it has been pressed on 13mm.
Fitting the crank on a JIS specialized bottom bracket from an old mtb, it goes on 9.5mm.

Sheldon said it would be as much as 4.5mm difference each side, but this appears to show it's more like 1.5mm each side.

The bottom bracket is a 68mm Cinelli BSA on a columbus SL Diamant frame.

My plan is to buy a 73 x 113mm UN55 (the narrowest 73mm size I can find) and space out the driveside 4mm, and the NDS, 1mm. That should account for the offset. And I think the q-factor of the crank should increase by ~1.5mm total which is negligable.
I considered buying the a campagnolo cartridge bottom bracket, and ignoring the offset, but I have one on another bike (centaur) and it has not lasted as long as I would expect a $100+ unit to. Un55 is going to be $35

Thoughts? Other ideas? Cheers.

Soody

JIS taper vs ISO taper

JIS:

ISO:

The other option I have (maybe a bit silly) is using a JIS tricolour NDS crank arm, which would account for some offset itself, and reduce the q-factor. The rest of the bike is a mix of campag & tricolour already so might be good. I'm just worried that experimenting with taper press fits will destroy the tapers, and it's best to do em once.

Dirk de Chablis

If the chainset has a self extractor bolt it is a Victory chain set, if it doesn't then it could be a Triomphe chain set. Triomphe uses a 115mm BB and Victory uses a 109mm, but you will need an ISO taper, if you use a JIS taper there will only be a 70% contact patch on the crank face. It might be ok or it might fail with a shimano BB and using your face as a brake isn't pleasant.

Victory BB eBay

Soody

It's definately 114.5 or close to that. I measured it with calipers man. And you can see in the picture against a ruler. Maybe the self extractor collar got added later. It's only on one crank arm.
I looked on ebay too. It's all really expensive. I have to pay high shipping to NZ also. And our $ is 70c on the $. This whole frame/wheels/crank cost me $140.
I would consider the right period BB but over $100 is too much. Some I've seen are like $300-400.

Re JIS vs ISO, i've read that it's not a binary between the two, and just looking visually, and actually comparing fits, they don't seem that different. How do you imagine it would fail catastrophically either? I imagine what might happen is it destroys the taper and loosens. But that wouldn't be catastrophic, it would just destory the crank. Not cause an accident.

I do hear you, buy the right thing, it makes sense. But I can't find it for a price i'd pay.

Soody

This is definitely 114.5. Maybe my calipers are messed and it's 114 or 115 but it's not 109.

Dirk de Chablis

Copied from another thread:

"The issue is absolutely not about any of that corporate ego that you refer to. It's a straight technical difference that anyone with a set of verniers can check and verify for themselves.

It's not a new taper - its a comparatively old, proprietary taper, developed back in the days when ISO had yet to define the ISO taper for use in bicycles and most makers had subtly different specs for their square taper interfaces. Campagnolo have never seen the need to update the tooling on the Pista BB and crank, as they advise that matching BB and cranks are used together. The Pista BB and crank have not changed since they were introduced in the early 1990s.

The use of the proprietory Campagnolo tapers used gave reverse compatibility to all BBs that Campagnolo had made before the introduction of C-Record and other square taper cranks of that generation.

The Pista taper has the same start square size as an ISO taper and the same 2 degree angle, however, there is a difference in the distance from the square face of the taper to the scallop where the taper changes from square section to the round section of the axle. As a result, the cranks migrate up the taper the same distance but the back of the crank, on an ISO taper, can foul the scallop (small manufacturing tolerance-related differences mean that it can sometimes *not* do so on first fitting but may do so on subsequent fittings).

If the back of the crank does foul the scallop, this puts a point load in the "corner" of the square taper on the crank, which eventually promotes cracking.

The form of the "corners" of the square taper is also slightly different to cope with back-lash loads on the taper but this is not the most significant problem."

GFK runs the UK Campag Service centre

Soody

Oh huh lol so this crank is not even ISO? But some similar standard?

As I have shown, the crank sits ~1.5mm further forward on a JIS taper, than on the original taper. I do not see how fouling the scallop can then be an issue. This quote seems applicable to using such a crank on an ISO bottom bracket. Which I would have possibly tried, if they weren't:
a: out of stock locally
b: $105
c: not offset
d: what you just posted

Dirk de Chablis

The first thing you need to address is which cranks they are, Campag Victory or Triomphe, they both look very similar but use different axle lenghts. But I think the extractor threads are different, a Victory crank w/o the self extractor bolts is useless unless you have the special Left handed thread extractor tool. I vaguely recall that the Triomphe is more normal and has right handed extractor threads on both sides

Soody

@verktyg
based on this too it's triomphe.
but man. I measured the axle. I showed you. We've already worked that out.

Soody

I bought the bike with the driveside crank off already, and the NDS crank on. But he gave me both. The seller basically bought it, then stripped it of parts then sold it. I think he got to the NDS crank arm, and didn't have a 13mm allen key lol. Because that's what it took to get that off. So he ended up giving me the crank because he couldn't get it all off. What allen key set has a 13mm anyway?? Mine didn't. But I just had one in the draw. Who knows where it came from. And that fit perfect and got it off. Anyway. I will check the crank threads tomorrow, see if my removal tool will thread in. Cheers for that.

Spaghetti Legs 

I have only used one Voctory crank, briefly, but have a lot of experience with same era Super Record, C-Record. With the SR, the asymmetric spindle was a CPSC requirement and was a modification to the previous 113 mm spindle. In your place, if the specified BB was too pricey, I’d look for a same era Record BB. The late 80’s, early Athena BB will be 111, but you can use spacers on the drive side. There is also a version with adjustable cups both sides. Phil Wood is another option, but pricey, in ISO.

Barring any of that and if you want to keep using the same crank, I’d go with a JIS spindle. My understanding is it won’t fail catastrophically, just possibly FUBAR the taper so that the crank may eventually bottom out on the spindle and become unusable.

Hope that helps.

JohnDThompson 

It's a Triomphe crank, which uses the same bottom bracket as Gran Sport, and interchanges with Record Strata (but NOT Nuovo Record). Boulder Bicycle was selling NOS Gran Sport BB spindles recently; perhaps they still might have one?

Soody

Good idea, i checked though, no dice.

Soody

Thanks man. I'm going to try bodge it. I would treat the bike differently if it was period and complete. It's just one part that will inevitably be part of a frankenbuild though, and that was before. It's nice, but I can only use it within the spectrum of it making practical sense to doso. I know this is kind of sacrilidgeous to go down a path which destroys the crank and these things are classic, but the un-55 should last years and years and I will get good riding out of it. I'll report back and say how it went. As much as we can fetishize campy they were once upon a time just the pragmatic things to use and that's the case here too if i bodge it. In a way it's in the spirit of campy.

Dirk de Chablis

But the issue is still there, if you have a Triomphe C/Set and a Victory NDS what ever BB you fit won't work, one side will always be off whether you use ISO or JIS, if you go down the JIS route, keep an eye on the inside of the spider for cracks, you wouldn't want to rattle your love spuds off the stem if it goes.

Soody

Why not? I got a 73mm bottom bracket, and then have 5mms of spacers to move around that can space out either side.
I can test fit it without torquing down the press fit too, so no potential taper damage while setting up.