boneshaker78

I would like to just clarify some information I’ve been reading in the forums about how the Campy Pista Record crank needs a specific bottom bracket. Something about the tapers not truly being ISO, but some propriety taper that is slightly different than ISO… is this true? It sounds a little strange to me and it seems like it might be controversial, but somebody on here mentioned that during the fixed gear boom in Europe people were cracking or deforming and destroying these pricey cranksets using the wrong bottom bracket (in professional shops as well). I picked one up as part of a bike recently and I’m not certain the current bottom bracket is appropriate (taper and chainline) or what I should get to replace it. Sort of tough to justify $200 bottom brackets, it would be nice to find a cheaper one with the right tapers.

It appeared that the consensus was that Phil Wood bottom brackets were acceptable. Why would that be? Don’t they have your typical ISO too? The bike I have has Phil BB cups but I haven’t removed it yet to see what is actually there.

This is what was said by jfk velo… https://www.bikeforums.net/singlespe...-frame.htmlthe

“Careful! Campag Pista is NOT a standard ISO taper and we have seen LH crank failures when mated to standard ISO tapers (including current Campag road BBs) and also when mounted to JIS.

We saw quite a few of these with the UK Hipster craze for mounting Campag Pista cranks to road-going bikes a few years ago - the Centaur 111 mm BB was used (because it's sealed for use in the rain, which the Pista BB isn't, for obvious reasons), with mechanics assuming that the tapers were the same ... one guy had three failures before he contacted us and we were able to explain ...

With JIS, you probably won't be getting enough engagement on the taper to be sure to avoid localised stress cracking. You'll be voiding any warranty as well.”

.

cxwrench

They're all 2* tapers, they just start and end at different dimensions. I can't remember off the top of my head but if you mess up your crank arm either goes on too far or not far enough. Too far and you might not be able to get it properly tightened, not far enough you might break the crank arm.

boneshaker78

I’m afraid I’m not following. What is 2* taper?

79pmooney

2 degrees.

Look into Miche BBs. (around $70 pre-pandemic) I don't know what they claim to be but I imagine they are compatible with Campy. 20,000 miles says they work just fine with Sugino 75s which I believe are Campy compatible. Miche/75 chainline falls right on for me. Haven't measured but they line up with my Miche hubs nicely.

boneshaker78

2 degrees makes sense, but I still don’t understand what would be compatible and safe with this crank. My question remains.. what’s with the special ISO taper? I’d imagine Miche are ISO, but apparently that might not be correct either.

Andrew R Stewart 

Safe- That is much more about paying attention to your equipment than any initial slight miss match of BB axle taper dimensions. If you can't judge how tight you've run up a fitting...

Compatible- Even understanding the various historical taper dimensions do know that tolerances exist, wear can change the crank hole dimension and sound judgement is always depended on. Generally one wants a axle/hole overlap so the axle end is a few (what's a few between friends) MMs inboard of the crank arm's hole outer end, after tightening the retaining bolts.

Real life- How far up any one axle's flats will a certain crank arm travel (after torqued retaining bolts) can vary slightly. If the arm has been mounted before that might have left a slight ridge on the square hole's flats and impede the arm from drawing up on the next axle (and making before install assessment harder). Parts are not machined exactly the same, even within the same production series. These days tolerances are better controlled than back when the taper standards were "looser" but still they drift a bit.

I can't give you a parts list other than what Campy has and guaranty that some other mix will work and, of course, Campy won't tell you that some other's part will interchange. Some of the cost of doing this stuff yourself is being able to "write off" a purchase that turns out to not work. Many might be surprised how often this happens for pros too. Andy

FBinNY 

Two IMPORTANT considerations.

1- the Campy taper is the same as any other (just about), however the starting point is larger, so other spindles may be extend too far into the crank, and be impossible to tighten, This is fixable if you have patience and access to a grinder. Note, if you do modify a spindle be sure to put a lead taper on so there's no edge that would shave the crank.

2- road spindles of the era were 120mm, but this crank wants a 110mm spindle to product correct chain line. If using another brand spindle, the crank may slide farther up, so you'll need a spindle a bit longer.