installing crown race on all-carbon fork?

[Andy Coggan]

New bike with all-carbon fork (legs/crown/steerer) and integrated headset. Crown race seat measures
26.4 mm, whereas split crown race of headset spec'd
w/ bike expands to a maximum of 25.5 mm when inserted into cartridge bearing. As a result, when
placed by hand crown race/bearing bottom out on fork about 2 cm above crown race seat. W/o the
cartridge bearing, crown race expands to fit over crown race seat, but then is too large in
diameter to fit into cartridge bearing. My questions are:

1) does all this sound normal?

2) if so, do you just force the crown race/bearing into place as you would with a metal fork? and/or

3) is it sometimes necessary to sand the crown race seat to remove excess clearcoat/epoxy?

Andy Coggan

 

[A Muzi]

"Andy Coggan" <[email protected]> wrote in message
news:[email protected]...
> New bike with all-carbon fork (legs/crown/steerer) and integrated headset. Crown race seat
> measures 26.4 mm, whereas split crown race of headset
spec'd
> w/ bike expands to a maximum of 25.5 mm when inserted into cartridge bearing. As a result, when
> placed by hand crown race/bearing bottom out on fork about 2 cm above crown race seat. W/o the
> cartridge bearing, crown
race
> expands to fit over crown race seat, but then is too large in diameter to fit into cartridge
> bearing. My questions are:
>
> 1) does all this sound normal?
>
> 2) if so, do you just force the crown race/bearing into place as you would with a metal fork?
> and/or
>
> 3) is it sometimes necessary to sand the crown race seat to remove excess clearcoat/epoxy?

I am not an expert here but are you sure you don't have the _top_ split ring- which should
be 25.4mm?

Generally, "alternate materials" do not get milled as small as a steel crown, e.g., aluminum and
carbon crowns cut with a mill designed for a steel seat end up loose.
--
Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971

 

[Andy Coggan]

"A Muzi" <[email protected]> wrote in message news:[email protected]...
> "Andy Coggan" <[email protected]> wrote in message
> news:[email protected]...
> > New bike with all-carbon fork (legs/crown/steerer) and integrated
headset.
> > Crown race seat measures 26.4 mm, whereas split crown race of headset
> spec'd
> > w/ bike expands to a maximum of 25.5 mm when inserted into cartridge bearing. As a result, when
> > placed by hand crown race/bearing bottom out
on
> > fork about 2 cm above crown race seat. W/o the cartridge bearing, crown
> race
> > expands to fit over crown race seat, but then is too large in diameter
to
> > fit into cartridge bearing. My questions are:
> >
> > 1) does all this sound normal?
> >
> > 2) if so, do you just force the crown race/bearing into place as you
would
> > with a metal fork? and/or
> >
> > 3) is it sometimes necessary to sand the crown race seat to remove
excess
> > clearcoat/epoxy?
>
>
> I am not an expert here but are you sure you don't have the _top_ split ring- which should
> be 25.4mm?

That may very well be it - the installation instructions for the headset (Cane Creek IS) aren't
clear, indicating only that the crown race may be be split for easier installation.

Andy Coggan

 

[Tony Raven]

In news:[email protected], Andy Coggan
<[email protected]> typed:
> New bike with all-carbon fork (legs/crown/steerer) and integrated headset. Crown race seat
> measures 26.4 mm, whereas split crown race of headset spec'd w/ bike expands to a maximum of 25.5
> mm when inserted into cartridge bearing. As a result, when placed by hand crown race/bearing
> bottom out on fork about 2 cm above crown race seat. W/o the cartridge bearing, crown race expands
> to fit over crown race seat, but then is too large in diameter to fit into cartridge bearing. My
> questions are:
>
> 1) does all this sound normal?
>
> 2) if so, do you just force the crown race/bearing into place as you would with a metal fork?
> and/or
>
> 3) is it sometimes necessary to sand the crown race seat to remove excess clearcoat/epoxy?
>

Something is wrong. It may be necessary to remove the odd thou or two to get a good and relatively
easy fit but almost a mm out is too far out. Are you sure its the right race?

Tony

--
http://www.raven-family.com

"All truth goes through three steps: First, it is ridiculed. Second, it is violently opposed.
Finally, it is accepted as self-evident." Arthur Schopenhauer

 

[Richard Chan]

"Tony Raven" <[email protected]> wrote in message
news:<[email protected]>...
> > 1) does all this sound normal?
> >
> > 2) if so, do you just force the crown race/bearing into place as you would with a metal fork?
> > and/or
> >
> > 3) is it sometimes necessary to sand the crown race seat to remove excess clearcoat/epoxy?
> >
>
> Something is wrong. It may be necessary to remove the odd thou or two to get a good and relatively
> easy fit but almost a mm out is too far out. Are you sure its the right race?

Mic the diameter of the crown race and the fork steerer seat. I suspect there is too much
interference. I had two issues w/Cane Creek (threadless but not the integrated models). My LBS had
to cut away some material on my Mizuno in order to seat the race. I also called Cane Creek about a
new crown race/bearing because it wouldn't seat right (1/4" too high). They will send you a new
unit for free.