eajohnson

OK, noobie first post here. Yes I searched the forum already and yes I googled the problem and yes I looked at the CK web site and also have emailed CK.

So, I have a classic 1984 Zullo that I am restoring at significant expense.

I had intended to replace the old brinelled campy headset with a CK and actually purchased a 2nut 1" CK headset for the job. The problem is, as I realize having just removed the old crown race, that the CK crown race and in fact total lower stack height (which is what I care about) is several mm lower than the original campanolo headset, which just isn't going to work for me. Being off by several mm is just too much for my purposes I want my bike to be restored to its original geometry more or less exactly, considering the expense I'm going to to restore this bike which has significant sentimental value to me since it was my first serious race bike.

Does anyone know of a solution that can be purchased off the shelf? I know I could engage a machine shop to create a crown race but that's likely to be more expensive than throwing the CK in the dustbin and buying a NOS campy off ebay.

Things that come to mind:

- add a 2mm shim above the lower head tube race, before pressing in the lower head tube race to the head tube (less of it would therefore be actually in the head tube though - would 2-3mm matter? Also subject to alignment problems if not absolutely perfect.)
- add a 2mm shim below the CK base plate/crown race (subject to alignment problems if not absolutely perfect)
- find another manufacturer base plate that might be 'compatible enough' with the CK lower bearing that is thicker, and use that instead
- or ....?

FWIW I need a solution that will cost under $150, that's pretty much my ceiling for what this is worth to me, otherwise I'm just going to find a NOS campy part off ebay.

TiBikeGuy

Are you a noobie in riding bicycle ? A 2mm difference and will this affects the bike's geometry ? Is your body sensitive enough to feel the bike being 2 mm lower than before?

You need to put more km on the bike than to worry about mm things.

eajohnson

Completely unhelpful.

Anyone else?

zonatandem

Get a c/f spacer.

fietsbob

Yea, if the top locknut flange bottoms out , on the top of the fork-steer tube,
before you can exert any force , on the adjustable cup, to hold its adjustment,
add a spacer in between ..

eajohnson

Yes, I'd thought of using a spacer, not CF but aluminum or steel because it needs to be silver or chrome colored, the issue is finding one of the right size (26.4mm to fit between the crown race and the fork, or a larger size to fit between the lower head tube race and the head tube). A 1" spacer such as is available from Nashbar in aluminum might not have quite large enough ID, since the press fit area of the tube is slightly more than 1" i.e. 1.0385". Also the smallest size is 3mm, I might need slightly less. I guess I could also sand the ID of a spacer until it fits, presumably being slightly off center would not be that significant as long as the top and bottom faces are machined perfectly. If I'm within 0.5mm of the original stack height I don't think I could see the difference (and seeing the difference does matter to me). Anyone actually done this? I've googled this and of course had seen people looking for spacers etc but have not located evidence of anyone being sucessful with it. Often times they are discouraged from that course but I don't know whether the naysayers were doing so out of actual experience or just a general thinking that maybe it wasn't a good idea.

eajohnson

It's not the top I'm concerned with, it's the bottom stack height, affecting distance from the hub to the head tube as well as the top tube being perfectly level which it should be on this bike. With the 2nut I can add spacers galore up top the only pressure the spacer is under would be the tension from the top lock nut. So I'm not concerned about the top locknut bottoming out. But I would think the bottom is different, any spacers I put there there to adjust the bottom stack height are right in line to take road shock.

fietsbob

take accurate measurements , submit dimensioned drawings..

show me the difference.

eajohnson

With a caliper, in an unassembled state i.e. the crown race hand pressed against the bearing in both cases, rather than being pressed in an assembled state, the campy headset is 14.90mm and the CK is 13.13mm. So there is about 2mm to make up. I'll assume that you know what the bottom part of a headset looks like LOL.

surreal

Sell the king; buy an NOS or minty Campy headset that will suit your needs. Lightly used kings still command a nice price. =D I understand the perfectionism you're striving for; i believe that the surest and cheapest route is to go with the oem headset.

hth
-rob

eajohnson

You may well be right. I'm simultaneously looking into that. It's too bad, the king headset is beautiful and light compared to the original campy one.

miamijim

ea....I see no real fix to the CK fitment issue. I've seen enough loose fitting lower cups and fork races in my time that I wouldn't shim either one.

sorry, but your only real option is buy a complete Campy headset or just the parts you need to replace the brinelled parts. You can find individual pieces on ebay. They're not cheap but they're also cheaper than a complete headset.

fietsbob

only bottom half stack thickness matters. that (CK) alters the head angle by how many degrees? 0.3?

I agree ,if it matters to you a lot get another <C> headset..



Not got CAD ,, ?

miamijim

Do you have anything better to do than bust peoples balls?

It's an '84 Zullo therefore its doesnt have a <C> headset.

fietsbob

Zullo does not make headsets. just frames ...

miamijim

Let me check my rocket scientist hand book.....you are correct.

fietsbob

Never knew the rampant OCD among bicycle buyers , till I visited here..

cny-bikeman

What I understand is that the solution you proposeis to add a 2mm spacer to the bottom headset cup or the crown race before insertion. So in order to make your top tube level you are going to sacrifice the appearance of the front of your bike and proper engagement of the cup/race.

At the risk of being unhelpful that seems like a big price to pay. Besides, won't the top tube actually be MORE level when you are riding if the front is lower when you are off the bike?

eajohnson

Thanks, that's useful input as to another concern of shimming that I hadn't thought of - that the resulting fit could be loose e.g. if the ID of the head tube or the OD of the fork where the crown race fits has any taper at all in either case, then shimming could result in a loose fit. Definitely something I'd need to watch for.

eajohnson

That's not really being unhelpful at least you're actually understanding the problem and talking about real potential drawbacks. On topic = helpful so thanks.

The best solution for function and aesthetics IMO would be to find an alternative crown race that is thicker and would be compatible with the CK headset. The other options, other than giving up on the CK and going to Campy, are admittedly kludgy and I'm not super happy with the whole idea of the shim but could be persuaded if I could find others that did it successfully. There must be several thousand other people before me that have faced the same thing when restoring older bikes.

fietsbob

Custom machine a shim to go under the crown race ? exact thickness required is possible then..

CK 'Crown race' is Stainless Steel ring shim can be aluminum.. or brass..