Residual stress, fatigue and stress relief

[Ron Ruff]

On Apr 25, 10:09 pm, jim beam <[email protected]> wrote:
> that hub hole deformation is *definitely* going to affect exit angle.
> and thus "correcting" the spoke line /before/ tensioning [and
> stabilizing], as most people do, is going to be premature.

Exactly when and how much can be debated I suppose, but... Every hub I
use supports the spoke in such a way as to make the heads-in spokes
"stick out" ie they aren't heading straight to the rim but rather bow
outward. Increasing tension (even overloading) will not eliminate this
completely... so the spoke will end up with an additional bending
load, if nothing else is done about it. This is not a good thing.
Similarly, most rims I use do not allow spokes on the NDS and front
spokes to enter without some bending load at the rim. Some large
flange hubs create a pretty acute angle even on the DS.

I prefer to "correct the spoke line" at the hub rather late in the
building process, but before overloading. I agree that high tension is
probably better for achieving the best "shape" at that point. At the
rim I bend the spokes fairly early, just because it is too difficult
to do well when the tension is high. It seems to me that it is better
for the rim if the nipple lies more closely to perpendicular against
the surface of the rim, to reduce the chance of eyelet deformation and
cracking.

 

[jim beam]

Ron Ruff wrote:
> On Apr 25, 10:09�pm, jim beam <[email protected]> wrote:
>> that hub hole deformation is *definitely* going to affect exit angle.
>> and thus "correcting" the spoke line /before/ tensioning [and
>> stabilizing], as most people do, is going to be premature.
>
> Exactly when and how much can be debated I suppose, but... Every hub I
> use supports the spoke in such a way as to make the heads-in spokes
> "stick out" ie they aren't heading straight to the rim but rather bow
> outward.

only when the hub is new and the hub holes un-deformed. to bend the
spoke a head of this deformation is premature because hub hole
deformation changes the exit angle. and it's the angle to which spokes
are pre-formed!

> Increasing tension (even overloading) will not eliminate this
> completely... so the spoke will end up with an additional bending
> load, if nothing else is done about it.

that's not correct. both dave ornee and i have posted pics of spokes
that are unbent, and when disassembled, they prove that bending was
unnecessary.


> This is not a good thing.

no, it's a misunderstanding and non-observation of the facts. see above.


> Similarly, most rims I use do not allow spokes on the NDS and front
> spokes to enter without some bending load at the rim. Some large
> flange hubs create a pretty acute angle even on the DS.
>
> I prefer to "correct the spoke line" at the hub rather late in the
> building process, but before overloading. I agree that high tension is
> probably better for achieving the best "shape" at that point. At the
> rim I bend the spokes fairly early, just because it is too difficult
> to do well when the tension is high. It seems to me that it is better
> for the rim if the nipple lies more closely to perpendicular against
> the surface of the rim, to reduce the chance of eyelet deformation and
> cracking.
>

you have to overload to ensure bedding in - if you want your wheels to
remain true at any rate. and if your spoke tension is high enough to
cause rim deformation, it's too high - use a tension meter.

 

[jim beam]

jim beam wrote:
> Ron Ruff wrote:
>> On Apr 25, 10:09�pm, jim beam <[email protected]> wrote:
>>> that hub hole deformation is *definitely* going to affect exit angle.
>>> and thus "correcting" the spoke line /before/ tensioning [and
>>> stabilizing], as most people do, is going to be premature.
>>
>> Exactly when and how much can be debated I suppose, but... Every hub I
>> use supports the spoke in such a way as to make the heads-in spokes
>> "stick out" ie they aren't heading straight to the rim but rather bow
>> outward.
>
> only when the hub is new and the hub holes un-deformed. to bend the
> spoke a head

typo - "ahead"

> of this deformation is premature because hub hole
> deformation changes the exit angle. and it's the angle to which spokes
> are pre-formed!
>
>> Increasing tension (even overloading) will not eliminate this
>> completely... so the spoke will end up with an additional bending
>> load, if nothing else is done about it.
>
> that's not correct. both dave ornee and i have posted pics of spokes
> that are unbent, and when disassembled, they prove that bending was
> unnecessary.
>
>
>> This is not a good thing.
>
> no, it's a misunderstanding and non-observation of the facts. see above.
>
>
>> Similarly, most rims I use do not allow spokes on the NDS and front
>> spokes to enter without some bending load at the rim. Some large
>> flange hubs create a pretty acute angle even on the DS.
>>
>> I prefer to "correct the spoke line" at the hub rather late in the
>> building process, but before overloading. I agree that high tension is
>> probably better for achieving the best "shape" at that point. At the
>> rim I bend the spokes fairly early, just because it is too difficult
>> to do well when the tension is high. It seems to me that it is better
>> for the rim if the nipple lies more closely to perpendicular against
>> the surface of the rim, to reduce the chance of eyelet deformation and
>> cracking.
>>
>
> you have to overload to ensure bedding in - if you want your wheels to
> remain true at any rate. and if your spoke tension is high enough to
> cause rim deformation, it's too high - use a tension meter.