cable stop strength

  • Thread starter Francesco Devittori
  • Start date



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Francesco Devittori

Guest
Hi all,

I just repaired the rear derailleur cable stop that broke off from my
carbon fiber chainstay, but I don't know if it will hold in the long
run.

Is there a standard way to test this? How do frame builders do it?

Thanks,
Francesco
 
Francesco Devittori wrote:
> Hi all,
>
> I just repaired the rear derailleur cable stop that broke off from my
> carbon fiber chainstay, but I don't know if it will hold in the long
> run.
>
> Is there a standard way to test this? How do frame builders do it?
>
> Thanks,
> Francesco


How was it originally attached? How did it become detached? Was there
any damage to the chainstay? How did you re-attach it?

To better serve you,

D'ohBoy
 
D'ohBoy wrote:
> Francesco Devittori wrote:
> > Hi all,
> >
> > I just repaired the rear derailleur cable stop that broke off from my
> > carbon fiber chainstay, but I don't know if it will hold in the long
> > run.
> >
> > Is there a standard way to test this? How do frame builders do it?
> >
> > Thanks,
> > Francesco

>
> How was it originally attached? How did it become detached? Was there
> any damage to the chainstay? How did you re-attach it?
>
> To better serve you,
>
> D'ohBoy


The cable stop is a square alu thing. It was fixed with a little screw
and very little glue (the bike is a first-generation C40).
I was able to drill out the broken screw, then attach the stop with a
similar screw and a good amount of bi-component epoxy glue (called
Araldit, I don't know if it's a known brand -it is here).
I guess the glue is what keeps things together, I don't think the screw
alone is strong enough to keep the cable stop in place under force.

A good thing is that the contact surface is relatively large and the
shape of the cable stop is a bit rounded and matches the chainstay.
Before gluing I roughed both surfaces with sandpaper and cleaned them
well.
It's now sitting for 24 hours, but already after a couple of hours I
was not able to move the cable stop with all the force of my hand.

What I'm most concerned is the long term durability (also cold
conditions/etc).
I don't want that it detaches in the middle of a race...
 
Francesco Devittori wrote:
> D'ohBoy wrote:
>> Francesco Devittori wrote:
>>> Hi all,
>>>
>>> I just repaired the rear derailleur cable stop that broke off from my
>>> carbon fiber chainstay, but I don't know if it will hold in the long
>>> run.
>>>
>>> Is there a standard way to test this? How do frame builders do it?
>>>
>>> Thanks,
>>> Francesco

>> How was it originally attached? How did it become detached? Was there
>> any damage to the chainstay? How did you re-attach it?
>>
>> To better serve you,
>>
>> D'ohBoy

>
> The cable stop is a square alu thing. It was fixed with a little screw
> and very little glue (the bike is a first-generation C40).
> I was able to drill out the broken screw, then attach the stop with a
> similar screw and a good amount of bi-component epoxy glue (called
> Araldit, I don't know if it's a known brand -it is here).
> I guess the glue is what keeps things together, I don't think the screw
> alone is strong enough to keep the cable stop in place under force.
>
> A good thing is that the contact surface is relatively large and the
> shape of the cable stop is a bit rounded and matches the chainstay.
> Before gluing I roughed both surfaces with sandpaper and cleaned them
> well.
> It's now sitting for 24 hours, but already after a couple of hours I
> was not able to move the cable stop with all the force of my hand.
>
> What I'm most concerned is the long term durability (also cold
> conditions/etc).
> I don't want that it detaches in the middle of a race...
>

should be stronger than the original. unless you have derailleur
problems that cause significantly excess tension, it should be fine.
 
jim beam wrote:
> Francesco Devittori wrote:
> > [...]
> > I was able to drill out the broken screw, then attach the stop with a
> > similar screw and a good amount of bi-component epoxy glue (called
> > Araldit, I don't know if it's a known brand -it is here).
> > [...]

>
> should be stronger than the original. unless you have derailleur
> problems that cause significantly excess tension, it should be fine.


Thanks! This gives me some peace of mind.
I can now sleep better :)

Francesco
 
On 10 Dec 2006 08:28:41 -0800, "Francesco Devittori"
<[email protected]> may have said:

>
>D'ohBoy wrote:
>> Francesco Devittori wrote:
>> > Hi all,
>> >
>> > I just repaired the rear derailleur cable stop that broke off from my
>> > carbon fiber chainstay, but I don't know if it will hold in the long
>> > run.
>> >
>> > Is there a standard way to test this? How do frame builders do it?
>> >
>> > Thanks,
>> > Francesco

>>
>> How was it originally attached? How did it become detached? Was there
>> any damage to the chainstay? How did you re-attach it?
>>
>> To better serve you,
>>
>> D'ohBoy

>
>The cable stop is a square alu thing. It was fixed with a little screw
>and very little glue (the bike is a first-generation C40).
>I was able to drill out the broken screw, then attach the stop with a
>similar screw and a good amount of bi-component epoxy glue (called
>Araldit, I don't know if it's a known brand -it is here).
>I guess the glue is what keeps things together, I don't think the screw
>alone is strong enough to keep the cable stop in place under force.
>
>A good thing is that the contact surface is relatively large and the
>shape of the cable stop is a bit rounded and matches the chainstay.
>Before gluing I roughed both surfaces with sandpaper and cleaned them
>well.
>It's now sitting for 24 hours, but already after a couple of hours I
>was not able to move the cable stop with all the force of my hand.
>
>What I'm most concerned is the long term durability (also cold
>conditions/etc).
>I don't want that it detaches in the middle of a race...


I'd say it should be good for a couple of years at least, as long as
the aluminum's surface was not contaminated with anything that would
eventually degrade the bond. There's a good chance that it'll last a
long as the chainstay.

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