Shortening a Carbon Fork

[Jeff]

I'm new to Carbon Forks. ...have a used Serotta Frame with their F2 Carbon
fork and Carbon Steerer that I just bought.

The fork already has one of the "wedges" in it (or whatever they are
called).

In reading directions for cutting and sizing the steerer tubes, I had
assumed that I would be using a standard star nut.

I'm now seeing some discussion that the metal star nuts are for use with
metal steerers but not for carbon ones and that the carbon ones require a
"wedge" to be epoxied inside that will accept a bolt from the headcap of the
headset.

My current fork already appears to have one of these installed.

....but if I wish to shorten the fork by about 1.5 to 2 inches, what should I
do in term of that old wedge?

I didn't initially realize that it was apparently epoxied in.

I could simply add spacers above the headset, but that's not a good idea to
leave them that high.

How is this handled? ...removing that old "wedge" and putting in a new one
after shortening the tube?

Where do I buy a new wedge?

Perhaps I'm reading the wrong thing and most of these are not epoxied?

Thanks

Jeff



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[Lou Holtman]

Jeff wrote:

> How is this handled? ...removing that old "wedge" and putting in a new one
> after shortening the tube?

I don''t know.
>

> Where do I buy a new wedge?

Every decent LBS has them. Measure the inner diameter of the steerer.
>
> Perhaps I'm reading the wrong thing and most of these are not epoxied?

Epoxied? Never heard of that. All mine are not epoxied.

Lou
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[[email protected]]

On Sep 27, 8:12 pm, "Jeff" <[email protected]> wrote:
> I'm new to Carbon Forks. ...have a used Serotta Frame with their F2 Carbon
> fork and Carbon Steerer that I just bought.
>
> The fork already has one of the "wedges" in it (or whatever they are
> called).
>
> In reading directions for cutting and sizing the steerer tubes, I had
> assumed that I would be using a standard star nut.
>
> I'm now seeing some discussion that the metal star nuts are for use with
> metal steerers but not for carbon ones and that the carbon ones require a
> "wedge" to be epoxied inside that will accept a bolt from the headcap of the
> headset.
>
> My current fork already appears to have one of these installed.
>
> ...but if I wish to shorten the fork by about 1.5 to 2 inches, what should I
> do in term of that old wedge?
>
> I didn't initially realize that it was apparently epoxied in.
>
> I could simply add spacers above the headset, but that's not a good idea to
> leave them that high.
>
> How is this handled? ...removing that old "wedge" and putting in a new one
> after shortening the tube?
>
> Where do I buy a new wedge?
>
> Perhaps I'm reading the wrong thing and most of these are not epoxied?
>
> Thanks
>
> Jeff
>
> --
> Posted via a free Usenet account fromhttp://www.teranews.com

You must use a carbon steerer specific expander, not a star nut. They
can be used in steerers of of materials as well. The one you have may
be just stuck and/or mounted with some hidden bolt. It should be
removable. Often there is a smaller hex bolt under the visible one
that is accesible through the larger hex opening. Epoxy sounds like a
bodge, but maybe I just don't know what I am talking about.

Joseph

 

[Jeff]

<[email protected]> wrote in message
news:[email protected]...
> On Sep 27, 8:12 pm, "Jeff" <[email protected]> wrote:
> You must use a carbon steerer specific expander, not a star nut. They
> can be used in steerers of of materials as well. The one you have may
> be just stuck and/or mounted with some hidden bolt. It should be
> removable. Often there is a smaller hex bolt under the visible one
> that is accesible through the larger hex opening. Epoxy sounds like a
> bodge, but maybe I just don't know what I am talking about.
>
> Joseph

Thanks Lou and Joseph,

The frame/fork is from 2002, so perhaps this is an older method? I've
checked by sticking a piece of wire down throught the threaded hole in the
metal insert inside of the fork and there does not appear to be anything
under the insert. As near as I can tell, the insert is epoxied in - it
certainly does not pull out when I apply pressure to the topcap. I did find
on the web one set of instructions related to Alpha-Q forks that speaks
about epoxying these things into carbon steerer tubes. ...perhaps an older
method or a method suggested by only a few fork makers?

....anyway, as near as I can tell, the insert goes down only about 3 cm, so
as long as I cut that much away, I think that the problem will be solved (as
long as excessive epoxy is not inside the steerer).

I've found almost no info on the web about this type of thing, however. I
suppose that if I cut the thing off with the excessive fork length, that I
can either carefully grind away anything that remains, or get a compression
fitting that will fit inside whatever part of the insert that remains.

....has no one else seen something like this?

Jeff




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[Kenny]

On Sep 28, 6:33 am, "Jeff" <[email protected]> wrote:
> <[email protected]> wrote in message
>
> news:[email protected]...
>

> it certainly does not pull out when I apply pressure to the topcap.

When you apply pressure to the top cap you are expanding the expansion
nut. If you want to remove it, remove the topcap then reinsert the
bolt. The bolt should be extend above the stem top about 3mm or so.
Now use a mallet or hammer to tap down on the bolt head. Once the
expansion nut moves down the tube a little you should be able to pull
it out via the bolt using pliers.

 

[Jeff]

"Kenny" <[email protected]> wrote in message
news:[email protected]...
> On Sep 28, 6:33 am, "Jeff" <[email protected]> wrote:
>> <[email protected]> wrote in message
>>
>> news:[email protected]...
>>
>
>> it certainly does not pull out when I apply pressure to the topcap.
>
> When you apply pressure to the top cap you are expanding the expansion
> nut. If you want to remove it, remove the topcap then reinsert the
> bolt. The bolt should be extend above the stem top about 3mm or so.
> Now use a mallet or hammer to tap down on the bolt head. Once the
> expansion nut moves down the tube a little you should be able to pull
> it out via the bolt using pliers.


I went to the LBS today and looked at their expansion plugs. The one in my
fork is not similar. It sits on the very top of the steerer tube - at least
a lip of this insert does - the rest goes down into the steerer about an
inch or so. I can't tap it down because the lip of the insert that sits over
the top of the steerer would prevent that. I can see nothing that would be
holding this insert in other than epoxy.

As long as it doesn't extend down further than the inch or so that's visible
from the top (to the point where the threads start), what I intend to cut
off will also cut off that insert/plug, so all should be okay. ...unless
there is more that is not visible.

....still a bit nervous about cutting into an expensive fork like this
without knowing more about that plug/insert.

Jeff


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[Kenny]

> I went to the LBS today and looked at their expansion plugs. The one in my
> fork is not similar. It sits on the very top of the steerer tube - at least
> a lip of this insert does - the rest goes down into the steerer about an
> inch or so. I can't tap it down because the lip of the insert that sits over
> the top of the steerer would prevent that. I can see nothing that would be
> holding this insert in other than epoxy.
>
> As long as it doesn't extend down further than the inch or so that's visible
> from the top (to the point where the threads start), what I intend to cut
> off will also cut off that insert/plug, so all should be okay. ...unless
> there is more that is not visible.
>
> ...still a bit nervous about cutting into an expensive fork like this
> without knowing more about that plug/insert.

Could you post a picture of this?
> Jeff
>
> --
> Posted via a free Usenet account fromhttp://www.teranews.com

 

[Jeff]

"Kenny" <[email protected]> wrote in message
news:[email protected]...
>
> Could you post a picture of this?


I found a web site (below) for Alpha-Q forks that contain something very
similar to what I have (don't have access to my camera to photograph my
actual fork). The insert on the website appears to be about 4" long from
what I can tell. I can't tell how long the insert is in my fork, because
there is a bottom plate with a threaded hole about 1 inch or so below the
top, and I can't of course, see what is under that. That threaded hole
accepts a standard headcap bolt. The insert may only be as long as the 1" I
can see, or that threaded bottom plate might be 1" down with an extra 3
inches below that I can't see. I'm unable to determine this. If I cut the
fork down by 1" and the insert is only as long as the 1" that I can see from
above, all should be okay if I use one of the expansion plugs as others
mention. If the insert goes down further, like the length shown on the
website below, I may be in trouble because a standard expansion plug might
not fit inside of the insert that is likely epoxied inside of my steerer
tube.

Any ideas?

http://www.bikemannetwork.com/biking/p/COMPHSPRTCAP/HD4701




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[Kenny]

On Sep 28, 11:26 am, "Jeff" <[email protected]> wrote:
> "Kenny" <[email protected]> wrote in message
>
> news:[email protected]...
>
>
>
> > Could you post a picture of this?
>
> I found a web site (below) for Alpha-Q forks that contain something very
> similar to what I have (don't have access to my camera to photograph my
> actual fork). The insert on the website appears to be about 4" long from
> what I can tell. I can't tell how long the insert is in my fork, because
> there is a bottom plate with a threaded hole about 1 inch or so below the
> top, and I can't of course, see what is under that. That threaded hole
> accepts a standard headcap bolt. The insert may only be as long as the 1" I
> can see, or that threaded bottom plate might be 1" down with an extra 3
> inches below that I can't see. I'm unable to determine this. If I cut the
> fork down by 1" and the insert is only as long as the 1" that I can see from
> above, all should be okay if I use one of the expansion plugs as others
> mention. If the insert goes down further, like the length shown on the
> website below, I may be in trouble because a standard expansion plug might
> not fit inside of the insert that is likely epoxied inside of my steerer
> tube.
>
> Any ideas?
>
> http://www.bikemannetwork.com/biking/p/COMPHSPRTCAP/HD4701
>
> --
> Posted via a free Usenet account fromhttp://www.teranews.com

That looks like a plastic tube used to reenforce the fork steerer.
Probably used to protect the CF in case someone was dumb enough to use
a "star fangled nut." A star fangled nut is used in metal fork
steerers only. But using this insert you could probably get away with
it. This part doesn't make sense unless the previous owner did pound
in a star fangled nut in which case it can not be removed without
using a drill.

Ok, I'm guessing that what you have is a "star fangled nut" that's
installed into a CF steerer that has a plastic tube epoxied in as
reenforcement. If this is the case. I would use a 7/8" round dole or
something similiar that is about 6 inches long. Use this dole and a
mallet to pound the star fangled nut down the steerer to near where
you want to cut the steerer as you'll still want to use it when you go
to adjust the headset. Use a hack saw and a cutting guide to cut the
steerer to your desired length.

 

[Jeff]

"Kenny" <[email protected]> wrote in message
news:[email protected]...

> Ok, I'm guessing that what you have is a "star fangled nut" that's
> installed into a CF steerer that has a plastic tube epoxied in as
> reenforcement. If this is the case. I would use a 7/8" round dole or
> something similiar that is about 6 inches long. Use this dole and a
> mallet to pound the star fangled nut down the steerer to near where
> you want to cut the steerer as you'll still want to use it when you go
> to adjust the headset. Use a hack saw and a cutting guide to cut the
> steerer to your desired length.

I understand what you're saying, but there is no star fangled nut. The
insert takes the place of the nut by having a bottom with a threaded hole in
it that accepts a standard bolt from the cap - so there is no need for the
star fangled nut. Although the insert on the web site looks like some type
of plastic, the one in my fork appears to be aluminum. I've read about
reinforcement tubes, but the only way that my insert would provide
reinforcement is if the tube section extended down below the visible bottom
where the threaded hole is. I can probably get an actual photo Saturday or
Sunday.

Jeff


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[Jeff]

"Kenny" <[email protected]> wrote in message
news:[email protected]...

> Ok, I'm guessing that what you have is a "star fangled nut" that's
> installed into a CF steerer that has a plastic tube epoxied in as
> reenforcement. If this is the case. I would use a 7/8" round dole or
> something similiar that is about 6 inches long.

Okay, just checked with both Serotta and with a better LBS in a nearby city.
The LBS had me optimistic as they showed me a few bikes that have similar
looking things that are actually expansion plugs - you take a very long
allen wrench that is about 4 or 5 mm and stick it through the larger
threaded hole that accepts the topcap bolt and it will loosen a wedge that
isn't visible further down the steerer tube. Unfortunately, Serotta has told
me that theirs is not this type (the F2 from 2002 at least, the newer ones
might be different)
and is, in fact, epoxied in. They didn't yet
tell me, however, whether there is a section that goes deeper that extends
below what I can see.

So if it does go below, I'm assuming that I might be able to use a star
fangled nut for a 1" tube (the inside diameter of the metal insert is about
22 mm or so) , and if it doesn't go below, I'm assuming that I can use a 1
1/8th expansion plug of some type.

Jeff



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[raelwelcome]

>
>
> I went to the LBS today and looked at their expansion plugs. The one
> in my fork is not similar. It sits on the very top of the steerer tube
> - at least a lip of this insert does - the rest goes down into the
> steerer about an inch or so. I can't tap it down because the lip of
> the insert that sits over the top of the steerer would prevent that. I
> can see nothing that would be holding this insert in other than epoxy.
>
> As long as it doesn't extend down further than the inch or so that's
> visible from the top (to the point where the threads start), what I
> intend to cut off will also cut off that insert/plug, so all should be
> okay. ...unless there is more that is not visible.
>
> ...still a bit nervous about cutting into an expensive fork like this
> without knowing more about that plug/insert.
>
> Jeff
>
>

Perhaps this is what you have inserted in the fork. There is a link on the
lower left of this web page. "Carbon Fork Insert"

http://cornercycle.com/

 

[Jeff]

<raelwelcome> wrote in message
news:[email protected]...
>
>
> Perhaps this is what you have inserted in the fork. There is a link on the
> lower left of this web page. "Carbon Fork Insert"
>
> http://cornercycle.com/


Yes, that is likely what I have. The top section that is visible is
identical and the total length listed on the web site of 100mm matches the
4" that Serotta told me to expect. The Serotta fork is/was made by Reynolds
and that insert states that it will work in Reynolds.

As you can see in the photo, if I cut off more than about an inch of the
steerer, I'll remove the threaded hole and will be left with a steerer with
a non-standard ID due to the wall thickness of the insert. Perhaps a 1"
(rather than a 1.125") star fangled nut or expander plug will fit inside the
metal insert.

After look at this more today, what I may do is to remove the 1" or so that
is above the threaded-hole-bottom-plate of the insert so that I won't have
to use any plug or nut and so that the plate remains to add reinforcement.
This will leave the steerer tube about an inch or so above the top of the
stem.

I'll have to do a few more measurements to see if that will work.

....any opinions?

Jeff




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[Kenny]

> I'll have to do a few more measurements to see if that will work.
>
> ...any opinions?
>
> Jeff
>
> --
The best way to figure out where to cut the steerer is to insert the
fork onto the bike. Put the amount of desired spacers on and then put
the stem on. Measure how far the steerer sticks out above the stem.
Remove fork from bike. To the total length of steerer above the stem
add another 2 to 5mm and mark this spot on the steerer. That is where
you will want to saw it.