Campagnolo 718 Crown Race Mill - spring question
 

Milling my first crown for headset install. Steerer tube is not cut down but is too short to get the spring on it when I mount the mill and the holder. Can’t compress spring anywhere near enough to mount the cutter holder.

Any tips appreciated. Thought there might be multiple spring lengths but don’t see any length but one. Thx

(also posted in Home Mechanics forum)

https://cimg0.ibsrv.net/gimg/bikefor...ac69181d8.jpeg
https://cimg2.ibsrv.net/gimg/bikefor...a870b7c5a.jpeg

@kanawa

https://brown-snout.com/cycling/tech...netts_ch05.pdf

5 - page 4 It says no problem without the spring.

I would encourage you to seek out someone who does this, its not for the unpracticed and there is little margin for error, you cannot put material back.

I had to opposite problem. The steerer tube was too long. I just milled it without the spring.

The spring is there to provide even pressure on the cutter. As long as you're careful to press evenly on both handles, you should be fine. And always turn clockwise; never counterclockwise, or you risk chipping the cutter.

yes, and the passa/no passa gauge was use first, correct?

https://cimg6.ibsrv.net/gimg/bikefor...b35967d5b.jpeg
https://cimg8.ibsrv.net/gimg/bikefor...36a113818.jpeg
https://cimg9.ibsrv.net/gimg/bikefor...67afe3206.jpeg
https://cimg0.ibsrv.net/gimg/bikefor...3e4d82a50.jpeg

yes that’s what I did. I used the cutter and placed the cutter holder upside down directly on top, without the spring. Milled it cleanly. Thank you

You're only half way there, with four photos showing the same thing, that the GO (passa) side fits over the crown race seat. Now flip the 732 tool over and check that the NOGO (non passa / red stripe) side does NOT fit. If it does, you took off too much material and likely have a problem.

You use it after cutting to check your work. You use it before cutting to determine if the work is necessary. Some mechanics think that milling a frame is a standard part of doing quality work, but if a frame doesn't need it (such as when it was done already by people who do it every day at the factory), it is not only a waste of time and cutting edges, but a risk that you may take off more material, ending up with an improper fit.

I had the frame repainted and there was excess paint where the race goes so I took that off. Installed the race. On to the rest of the headset…
https://cimg8.ibsrv.net/gimg/bikefor...51002c3cd.jpeg

Another instance where some more information upfront may well have altered advice and possibly produced a better outcome.

using the Campagnolo tool to just remove paint is ok but quite possibly will end up removing too much metal where it was previously set up for a Campagnolo headset. Some razor blade or judicious emery cloth scraping or better yet, masking at the respray, a much more metal safe method.

the Passa/ no passa gauge is really for use on an unknown steerer, or frame set with questionable prep to begin with.

there was no reference if the size gauge was before or after facing. Having the tools is only part of the solution.

A reference - a “coin” era Gios, the frame headtube was not showing any reaming, the fork had a split Super Record crown race -
it was never dressed. That was remedied, I guess the softness of the Super Record parts allowed the forced assembly. Not every shop had the correct tools nor awareness.

[QUOTE=repechage;23130065]Another instance where some more information upfront may well have altered advice and possibly produced a better outcome.

using the Campagnolo tool to just remove paint is ok but quite possibly will end up removing too much metal where it was previously set up for a Campagnolo headset. Some razor blade or judicious emery cloth scraping or better yet, masking at the respray, a much more metal safe method.

the Passa/ no passa gauge is really for use on an unknown steerer, or frame set with questionable prep to begin with.

there was no reference if the size gauge was before or after facing. Having the tools is only part of the solution.

A reference - a “coin” era Gios, the frame headtube was not showing any reaming, the fork had a split Super Record crown race -
it was never dressed. That was remedied, I guess the softness of the Super Record parts allowed the forced assembly. Not every shop had the correct tools nor awareness.[/QUOTE

Headset installed and is smooth throughout rotational arc. Thx for all those with supportive tips!

I milled clean the top and bottom of the steerer and everything went in beautifully. Thx again to the community.

the bike is a 1982 Jeff Lyon.
https://cimg2.ibsrv.net/gimg/bikefor...659619af2.jpeg

That explains why I liked the fork crown pics so much. A lyon is a great frame.
Head emblem says Kent, so was this made while he still was in England, or is the decal just a leftover from those days?

Here's the backstory, best as I can remember it. I bought this bike in 2021 for $700 and it came with a mix of bad components. Upon receiving it, I discovered the seat lug had a ~3/16" long vertical crack originating from the top of the lug. Seller refunded me $350 and we called it even. Jeff Lyon agreed to repair the lug and repaint the bike. He fixed the lug - confirmed it was good as new - and sent the frame back to me unpainted. He sent 2 NOS decals, both with the Kent location. I believe this frame was built when Jeff was in Northern California (Santa Rosa, I believe). He did a beautiful repair on the lug and I like that it was restored by the original master. As he didn't really paint anymore, I had it sprayed by a local guy. The paint isn't Joe Bell, but it's solid. Building it up with Nuovo Record group with high flange hubs. It is a lovely frame.