Building a wheel, applying it to an old Record Sprint.

[Pete Biggs]

[email protected] wrote:

>> I'm never quite sure how much tension is best, though (on the drive
>> side or on front wheels), so I might benefit from a course myself,
>> also to get the spokes on each side more even. It's difficult to
>> know how much tension the rim can take, I find: the limiting factor
>> with modern components.
>
> As part of our stress relieving, when the spokes were being tensioned
> towards the end, we squeezed as hard as possible on sets of four
> 'parallel' spokes (x3 lacing). Immediately following that though, if
> the wheel had become 'pringle' shaped then the tension was too much
> for the rim and spokes were all slackened off 1/2 turn then.

Thanks. I know that's Jobst Brandt's advice but I've been too chicken to
try it so far. Will do next time maybe, or perhaps some time on my
existing wheels, and re-tension.

My concerns are about possible damage to the rim to get to the pringle
state, and the possibility of the test not being good enough. I've
unexpectedly had rims pringle from pothole abuse that had spoke tension a
little higher than what I use now--tension that I /guess/ would have
passed the squeeze test.

Note: JB's favourite rim is MA2, much more substantial than Open Pro.

~PB

 

[Tony Raven]

Pete Biggs wrote:

>
> My concerns are about possible damage to the rim to get to the pringle
> state, and the possibility of the test not being good enough. I've
> unexpectedly had rims pringle from pothole abuse that had spoke tension a
> little higher than what I use now--tension that I /guess/ would have
> passed the squeeze test.
>

If you bought and read the book you would know that all the components
are operating at a small fraction of their limits. The idea of the
squeeze is not only does it stress relieve the spokes it also
overtensions them far more than they will see use. And if you think
about it hitting a pothole detensions the spokes round the impact zone,
not overtensions them.

Tony

 

[Pete Biggs]

Tony Raven wrote:

> If you bought and read the book you would know that all the components
> are operating at a small fraction of their limits. The idea of the
> squeeze is not only does it stress relieve the spokes it also
> overtensions them far more than they will see use.

I had read that before (JB repeats it on r.b.t endlessly) but I've still
got my doubts about the real limits.

> And if you think
> about it hitting a pothole detensions the spokes round the impact
> zone, not overtensions them.

That is true, but I think the wheel is still more likely to buckle if it's
already near to the point of collapse, especially from any lateral forces.
I would expect the rim to transmit force from the jolt to the spokes away
from the impact zone that will not be detensioned.

~PB

 

[Pete Biggs]

Tony Raven wrote:

> If you bought and read the book you would know that all the components
> are operating at a small fraction of their limits.

That's the kind of phrase Brandt uses himself, as if everything he writes
is true. It isn't. I know what he has written. That's not the same
thing as knowing the truth.

~PB

 

[[email protected]]

Pete Biggs wrote:
> [email protected] wrote:
>
> >> I'm never quite sure how much tension is best, though (on the
drive
> >> side or on front wheels), so I might benefit from a course myself,
> >> also to get the spokes on each side more even. It's difficult to
> >> know how much tension the rim can take, I find: the limiting
factor
> >> with modern components.
> >
> > As part of our stress relieving, when the spokes were being
tensioned
> > towards the end, we squeezed as hard as possible on sets of four
> > 'parallel' spokes (x3 lacing). Immediately following that though,
if
> > the wheel had become 'pringle' shaped then the tension was too much
> > for the rim and spokes were all slackened off 1/2 turn then.
>
> Thanks. I know that's Jobst Brandt's advice but I've been too
chicken to
> try it so far. Will do next time maybe, or perhaps some time on my
> existing wheels, and re-tension.

Interesting, I was a bit retiscent too (thinking that I had no spare
spokes) but the instructor was squeezing like hell, much more than I
could even manage. I think the spokes really can take a lot of that
kind of thing!

> My concerns are about possible damage to the rim to get to the
pringle
> state, and the possibility of the test not being good enough. I've
> unexpectedly had rims pringle from pothole abuse that had spoke
tension a
> little higher than what I use now--tension that I /guess/ would have
> passed the squeeze test.

I'm not sure but it seemed to be that, at the building stage, it was OK
for that kind of 'collapse' as long as you reduce the tension and carry
on just a little bit.

Like a saddo, I've just been twanging my new-built wheel spokes and
comparing them with my trued-up wheels from a bike shop and my
girlfriend's wheels (phrasing ripe for jokes).

I tell you one thing, looking back on the course with all eight of us
fiddling away, it got me thinking:

- my original trued-up wheel has barely any right-pitch tones on it
whatsoever and it wobbles like hell compared to the new one! However,
the wheel has had loads of awful abuse - up and down kerbs and,
recently, down two huge successive potholes that I didn't see that
nearly ended up with a crash as my hands slipped right off the
handlebars with my chin ending up wacking against the head set. The old
wheel carried on ... I trust it more than my new one which is still
untried!

- the girlfriend's machine-built wheels sound pretty goodish and really
are quite good (I think)

- my wheel is quite cool

- it would be quite funny to have a wheel building
masterclass/competition but even better would be to have a similar
course in London

- I wish I had more wheels to do!

> Note: JB's favourite rim is MA2, much more substantial than Open Pro.

We had the JB book at the course and another one, home-made, by a wheel
builder whose shop has now gone out of business but he still has some
copies of the book apparently. I'll try and find out the info' on it
because I forgot to take it down at the time.

ccc rider

 

[[email protected]]

Pete Biggs wrote:
> [email protected] wrote:
>
> >> I'm never quite sure how much tension is best, though (on the
drive
> >> side or on front wheels), so I might benefit from a course myself,
> >> also to get the spokes on each side more even. It's difficult to
> >> know how much tension the rim can take, I find: the limiting
factor
> >> with modern components.
> >
> > As part of our stress relieving, when the spokes were being
tensioned
> > towards the end, we squeezed as hard as possible on sets of four
> > 'parallel' spokes (x3 lacing). Immediately following that though,
if
> > the wheel had become 'pringle' shaped then the tension was too much
> > for the rim and spokes were all slackened off 1/2 turn then.
>
> Thanks. I know that's Jobst Brandt's advice but I've been too
chicken to
> try it so far. Will do next time maybe, or perhaps some time on my
> existing wheels, and re-tension.

Interesting, I was a bit retiscent too (thinking that I had no spare
spokes) but the instructor was squeezing like hell, much more than I
could even manage. I think the spokes really can take a lot of that
kind of thing!

> My concerns are about possible damage to the rim to get to the
pringle
> state, and the possibility of the test not being good enough. I've
> unexpectedly had rims pringle from pothole abuse that had spoke
tension a
> little higher than what I use now--tension that I /guess/ would have
> passed the squeeze test.

I'm not sure but it seemed to be that, at the building stage, it was OK
for that kind of 'collapse' as long as you reduce the tension and carry
on just a little bit.

Like a saddo, I've just been twanging my new-built wheel spokes and
comparing them with my trued-up wheels from a bike shop and my
girlfriend's wheels (phrasing ripe for jokes).

I tell you one thing, looking back on the course with all eight of us
fiddling away, it got me thinking:

- my original trued-up wheel has barely any right-pitch tones on it
whatsoever and it wobbles like hell compared to the new one! However,
the wheel has had loads of awful abuse - up and down kerbs and,
recently, down two huge successive potholes that I didn't see that
nearly ended up with a crash as my hands slipped right off the
handlebars with my chin ending up wacking against the head set. The old
wheel carried on ... I trust it more than my new one which is still
untried!

- the girlfriend's machine-built wheels sound pretty goodish and really
are quite good (I think)

- my wheel is quite cool

- it would be quite funny to have a wheel building
masterclass/competition but even better would be to have a similar
course in London

- I wish I had more wheels to do!

> Note: JB's favourite rim is MA2, much more substantial than Open Pro.

We had the JB book at the course and another one, home-made, by a wheel
builder whose shop has now gone out of business but he still has some
copies of the book apparently. I'll try and find out the info' on it
because I forgot to take it down at the time.

ccc rider

 

[Pete Biggs]

[email protected] wrote:
>>> As part of our stress relieving, when the spokes were being
>>> tensioned towards the end, we squeezed as hard as possible on sets
>>> of four 'parallel' spokes (x3 lacing). Immediately following that
>>> though, if the wheel had become 'pringle' shaped then the tension
>>> was too much for the rim and spokes were all slackened off 1/2 turn
>>> then.
>>
>> Thanks. I know that's Jobst Brandt's advice but I've been too
>> chicken to try it so far. Will do next time maybe, or perhaps some
>> time on my existing wheels, and re-tension.
>
> Interesting, I was a bit retiscent too (thinking that I had no spare
> spokes) but the instructor was squeezing like hell, much more than I
> could even manage. I think the spokes really can take a lot of that
> kind of thing!

No you've misunderstood me. I do squeeze the spokes (hard), I mentioned
stress relieving before. My concern isn't about the spokes themseleves,
but about using so much tension that the wheel is almost at the point of
collapse. I take the point on slackening the spokes back from the pringle
point, but how much back is really ideal is what I'm still doubtful over.
But forget my doubt!, it sounds like you had some very good instruction.

~PB

 

[Tony Raven]

[email protected] wrote:
>
> We had the JB book at the course and another one, home-made, by a wheel
> builder whose shop has now gone out of business but he still has some
> copies of the book apparently. I'll try and find out the info' on it
> because I forgot to take it down at the time.
>

Roger Musson of Wheelpro up in Preston. He builds awesome wheels. The
books are all sold out but he is doing an e-book version which you can
register for at http://www.wheelpro.co.uk/wheelbuilding/book.php.

AFAIK he did not go out of business but simply stopped the retail side
of the business.

Tony

 

[Tony Raven]

Pete Biggs wrote:
>
> That is true, but I think the wheel is still more likely to buckle if it's
> already near to the point of collapse, especially from any lateral forces.
> I would expect the rim to transmit force from the jolt to the spokes away
> from the impact zone that will not be detensioned.
>

Again read the book. The tension increase in the other spokes is
negligible. The main effect it to leave spokes either at their previous
tension or to detension them. Read the book and it would save all this
misguided folklore.

Tony

 

[Tony Raven]

Pete Biggs wrote:
>
> That's the kind of phrase Brandt uses himself, as if everything he writes
> is true. It isn't. I know what he has written. That's not the same
> thing as knowing the truth.
>

Yes but you are demonstrating that what Brandt knows is far closer to
the truth than your folklore which would have spoke tensions increasing
with wheel loads. If you read the calculations and finite element
analysis in the book you would know that spokes only decrease in tension
with wheel loading.

Tony

 

[Pete Biggs]

Tony Raven wrote:
> Pete Biggs wrote:
>>
>> That is true, but I think the wheel is still more likely to buckle
>> if it's already near to the point of collapse, especially from any
>> lateral forces. I would expect the rim to transmit force from the
>> jolt to the spokes away from the impact zone that will not be
>> detensioned.
>>
> Again read the book. The tension increase in the other spokes is
> negligible. The main effect it to leave spokes either at their
> previous tension or to detension them. Read the book and it would
> save all this misguided folklore.

I wasn't suggesting any spokes increased in tension, just that the wheel
can be deformed from that existing too-high tension when shocked.

~PB

 

[[email protected]]

Tony Raven wrote:
> [email protected] wrote:
> >
> > We had the JB book at the course and another one, home-made, by a
wheel
> > builder whose shop has now gone out of business but he still has
some
> > copies of the book apparently. I'll try and find out the info' on
it
> > because I forgot to take it down at the time.
> >
>
> Roger Musson of Wheelpro up in Preston. He builds awesome wheels.
The
> books are all sold out but he is doing an e-book version which you
can
> register for at http://www.wheelpro.co.uk/wheelbuilding/book.php.
>
> AFAIK he did not go out of business but simply stopped the retail
side
> of the business.
Yes, that's the one! Sorry about the misinformation.

ccc r

 

[Pete Biggs]

Tony Raven wrote:
> Pete Biggs wrote:
>>
>> That's the kind of phrase Brandt uses himself, as if everything he
>> writes is true. It isn't. I know what he has written. That's not
>> the same thing as knowing the truth.
>>
>
> Yes but you are demonstrating that what Brandt knows is far closer to
> the truth than your folklore which would have spoke tensions
> increasing with wheel loads.

I never suggested that tension increases.

> If you read the calculations and finite
> element analysis in the book you would know that spokes only decrease
> in tension with wheel loading.

Ditto.

Take a wheel with tension that is almost pringling the wheel then bash it
against something. What happens? That is the issue.

I think we agree on the principles, it just a question of degree.

~PB

 

[Pete Biggs]

Tony Raven wrote:
> Pete Biggs wrote:
>>
>> That's the kind of phrase Brandt uses himself, as if everything he
>> writes is true. It isn't. I know what he has written. That's not
>> the same thing as knowing the truth.
>>
>
> Yes but you are demonstrating that what Brandt knows is far closer to
> the truth than your folklore which would have spoke tensions
> increasing with wheel loads. If you read the calculations and finite
> element analysis in the book you would know that spokes only decrease
> in tension with wheel loading.

You're saying the same thing again: If I read X in The Book then I would
know X. By that reckoning I would "know" 16mm nipples had no more thread
than 12mm nipples. Well, I would know wrong because he got that wrong.

~PB