all carbon fork w/ carbon dropouts - ID??

[Bruce]

I saw an all carbon fiber fork at a flea market with no decals. Even the front wheel dropouts were
carbon, while all the forks I see in catalogs have aluminum droputs. This one appears to be aero
style with the upper legs wide (side view) and the frontal view shows the legs narrow at the top
third then curving out in the lower half to meet the hub.

Does anyone have any more info on these? Did they come stock on a time trial bike?

-Bruce

 

[Mike Jacoubowsk]

> I saw an all carbon fiber fork at a flea market with no decals. Even the front wheel dropouts were
> carbon, while all the forks I see in catalogs
have
> aluminum droputs. This one appears to be aero style with the upper legs wide (side view) and the
> frontal view shows the legs narrow at the top
third
> then curving out in the lower half to meet the hub.

I think you made a wise choice passing them up. Clamping a quick release onto carbon fiber doesn't
seem like a good idea, and the lack of decals indicates this might not be from a reputable firm.
Your life depends upon your fork... it's one area I don't think you should take chances.

--Mike-- Chain Reaction Bicycles http://www.ChainReactionBicycles.com

 

[Bruce]

"Mike Jacoubowsky" <[email protected]> wrote in message
news:[email protected]...
> > I saw an all carbon fiber fork at a flea market with no decals. Even
the
> > front wheel dropouts were carbon, while all the forks I see in catalogs
> have
> > aluminum droputs. This one appears to be aero style with the upper legs wide (side view) and the
> > frontal view shows the legs narrow at the top
> third
> > then curving out in the lower half to meet the hub.
>
> I think you made a wise choice passing them up. Clamping a quick release onto carbon fiber doesn't
> seem like a good idea, and the lack of decals indicates this might not be from a reputable firm.
> Your life depends upon your fork... it's one area I don't think you should take chances.
>

Have you seen many failures with carbon parts of any kind (not just forks). If so, then is there a
pattern to the cause of failure? Why would clamping a wheel be dangerous? Is it the pressure or the
scratches caused by the teeth of the skewer leading to cracks?

Pressure - stems are clamped on the steerer and no one here has complained about that. One
manufacturer (Colnago??)has a design to minimize the danger of scratches from clamping a stem by
using a flat spot on the rear side of the steerer so the stem clamp edges do not make contact with
the steerer.

So far the only fork I've found with fiber dropouts is the Wolf on the Cervelo webpage, but there's
no details there.

... still curious about this fork... -Bruce

 

[David E. Belche]

"Bruce" <[email protected]> wrote in message news:<[email protected]>...
>
> Pressure - stems are clamped on the steerer and no one here has complained about that. One
> manufacturer (Colnago??)has a design to minimize the danger of scratches from clamping a stem by
> using a flat spot on the rear side of the steerer so the stem clamp edges do not make contact with
> the steerer.
>

Conversely, there are stem designs intended to avoid damage to CF steerer tubes; Thomson is one
maker that springs to mind, no doubt there are others too.

David E. Belcher

Dept. of Chemistry, University of York

 

[Bruce]

Still no comments of any brands of forks that have zero metal in the droputs. IOW, the carbon
fibers extend all the way to the dropouts. Does anyone know of any forks that have no metal in
the dropouts?

Earlier I mentioned a manufacturer who discussed stress raisers and flat spots for the stem
attachment region. That was Easton in their seatpost and fork. I found that in a PDF file on their
webpage: "Relief Area Design"

-Bruce Frech

"David E. Belcher" <[email protected]> wrote in message
news:[email protected]...
> "Bruce" <[email protected]> wrote in message
news:<[email protected]>...
> >
> > Pressure - stems are clamped on the steerer and no one here has
complained
> > about that. One manufacturer (Colnago??)has a design to minimize the
danger
> > of scratches from clamping a stem by using a flat spot on the rear side
of
> > the steerer so the stem clamp edges do not make contact with the
steerer.
> >
>
> Conversely, there are stem designs intended to avoid damage to CF steerer tubes; Thomson is one
> maker that springs to mind, no doubt there are others too.
>
> David E. Belcher
>
> Dept. of Chemistry, University of York

 

[Mike Jacoubowsk]

> Have you seen many failures with carbon parts of any kind (not just
forks).
> If so, then is there a pattern to the cause of failure? Why would
clamping
> a wheel be dangerous? Is it the pressure or the scratches caused by the teeth of the skewer
> leading to cracks?

Carbon seatposts and bars have repeatedly demonstrated that carbon doesn't like to be compressed in
use. True, that's for a hollow carbon structure, and a fork dropout wouldn't be made that way. But I
suspect that even in a flat structure carbon wouldn't be an ideal material to exert large clamping
forces, since the epoxy matrix that holds it together would probably be subject to cracking.

--Mike-- Chain Reaction Bicycles http://www.ChainReactionBicycles.com

"Bruce" <[email protected]> wrote in message news:[email protected]...
>
> "Mike Jacoubowsky" <[email protected]> wrote in message
> news:[email protected]...
> > > I saw an all carbon fiber fork at a flea market with no decals. Even
> the
> > > front wheel dropouts were carbon, while all the forks I see in
catalogs
> > have
> > > aluminum droputs. This one appears to be aero style with the upper
legs
> > > wide (side view) and the frontal view shows the legs narrow at the top
> > third
> > > then curving out in the lower half to meet the hub.
> >
> > I think you made a wise choice passing them up. Clamping a quick
release
> > onto carbon fiber doesn't seem like a good idea, and the lack of decals indicates this might not
> > be from a reputable firm. Your life depends
upon
> > your fork... it's one area I don't think you should take chances.
> >
>
> Have you seen many failures with carbon parts of any kind (not just
forks).
> If so, then is there a pattern to the cause of failure? Why would
clamping
> a wheel be dangerous? Is it the pressure or the scratches caused by the teeth of the skewer
> leading to cracks?
>
> Pressure - stems are clamped on the steerer and no one here has complained about that. One
> manufacturer (Colnago??)has a design to minimize the
danger
> of scratches from clamping a stem by using a flat spot on the rear side of the steerer so the stem
> clamp edges do not make contact with the steerer.
>
> So far the only fork I've found with fiber dropouts is the Wolf on the Cervelo webpage, but
> there's no details there.
>
> ... still curious about this fork... -Bruce