Threadless headset questions/problems

[Scott Ghiz]

The threadless fork that I purchased seems OK except that the steerer tube has a slightly larger
diameter (more than 1") section that begins about 6mm or 1/4" above the fork. The bottom part of the
1" threadless headset cannot go past this point, thought it overlaps slightly. This effectively
leaves about a 3mm or 1/8" gap between the bottom of the headset (a sturdy metal ring) and the top
of the fork.

It seems logical the the headset should ride directly on top of the fork.

My questions:

1. Is there some sort of 'secret code' that I needed to match between the 1" threadless headset and
1" threadless fork?

2. Can I or should I add a couple of spacers between the top of the fork and bottom of the headset?

On top of all of these problems, my 2 year old son yanked the headset off the workbench and the top
housing cracked on the concrete floor. I just ordered a new headset. F^&K.

SG, the frustrated one.

PS - Thanks for the help in advance. I can post pictures to the internet if that would help.

 

[Bicyclette]

> 2. Can I or should I add a couple of spacers between the top of the fork and bottom of the
> headset?

No, I think what you are calling the bottom of the headset is the fork crown race. A disc like
piece. This piece is press fit on to the top of the fork. It has to go all the way to the surface
it sits on. Push it as far down as you can. Then put a rubber washer over it to protect it. Then
put the fork in a vice with padding to protect it and hold it. Then get a piece of 1,1/8 inch
diameter pvc tubing and whack it down gently increasing the whack force. That's what I did,
although I'm a novice.

 

[Mike Krueger]

I think it's better to pay the LBS a few bucks to do a proper headset installation than to try to do
it yourself without the proper tools or expertise. That assumes, of course, that your LBS has the
proper tools and expertise to do it.

 

[A Muzi]

Scott Ghiz wrote:

> The threadless fork that I purchased seems OK except that the steerer tube has a slightly larger
> diameter (more than 1") section that begins about 6mm or 1/4" above the fork. The bottom part of
> the 1" threadless headset cannot go past this point, thought it overlaps slightly. This
> effectively leaves about a 3mm or 1/8" gap between the bottom of the headset (a sturdy metal ring)
> and the top of the fork.
>
> It seems logical the the headset should ride directly on top of the fork.
>
> My questions:
>
> 1. Is there some sort of 'secret code' that I needed to match between the 1" threadless headset
> and 1" threadless fork?
>
> 2. Can I or should I add a couple of spacers between the top of the fork and bottom of the
> headset? -snip-

The lowermost bearing surface ( or bearing seat, in the case of a cartridge system) should be
26.4mm*, pressed onto a lip just above the fork crown of matching size. The rest of the column will
be about 25.4mm. Typically a slide hammer is used to set the lower race. It's best to check the
machined seat diameter with the appropriate Campagnolo 'go-nogo' gauge before smacking the parts.

Here's a point at which a competent LBS could be very helpful if there's a mensch in the
business near you.

*the older 27.1 format isn't relevant to new forks, AFAIK, but a measurement might be nice
--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971

 

[Scott Ghiz]

Thanks for everyone's help! I got the LBS to do the lower race install for me. Although, fairly
scarry sounds were coming from the backroom while the bike-tech was pounding on my carbon fork
:0 BTW, I loved the idea of getting some PVC pipe that fits over the steerer tube and then
banging away.

Thanks again!