Question on Re-using a Hub
Art Harris
my existing Ultegra freehub. The old and new wheel will use the same
lacing pattern (36H X3). Does it matter whether the spokes are oriented
the same way in the spoke holes of the hub (i.e., leading and trailing
spokes)?
Also, I'm planning to use 14-15-14 on the drive side and 15-16-15 on
the NDS. Any opinions on that? I weigh 190 lbs.
Thanks.
--
Art Harris
Long Island, NY
Sent via Deja.com http://www.deja.com/
Before you buy.
Jobst Brandt
> I'm contemplating building up a new rear wheel (new spokes/new rim) with
> my existing Ultegra freehub. The old and new wheel will use the same
> lacing pattern (36H X3). Does it matter whether the spokes are oriented
> the same way in the spoke holes of the hub (i.e., leading and trailing
> spokes)?
Yes. Deformation of spoke holes is usually significant and a second
pattern of metal flow of this magnitude can tear out flange sections
with sufficient use. I have a couple of Campagnolo Record hubs with
just such failures lying in my broken parts collection. Such failures
are also not warranted if there is evidence of two spoke patterns.
> Also, I'm planning to use 14-15-14 on the right side and 15-16-15 on
> the left. Any opinions on that? I weigh 190 lbs.
Use the same thinner spokes all around. The only reason to use
thicker spokes is to make truing easier by reducing twist. 1.8-1.6mm
spokes are plenty strong and will serve you well if properly tensioned
and stress relieved.
Jobst Brandt <jbr...@hpl.hp.com>
Qui si parla Campagnolo
lacing pattern (36H X3). Does it matter whether the spokes are oriented
the same way in the spoke holes of the hub (i.e., leading and trailing
spokes)? >>
Should lace so at least the drive side spokes are oriented the same way-
Peter Chisholm
"Vecchio's" Bicicletteria
1833 Pearl ST.
Boulder, CO
(303)440-3535
http://www.vecchios.com
A Muzi
convinced otherwise here 2 weeks ago.
Art Harris wrote:
> I'm contemplating buiding up a new rear wheel (new spokes/new rim) with
> my existing Ultegra freehub. The old and new wheel will use the same
> lacing pattern (36H X3). Does it matter whether the spokes are oriented
> the same way in the spoke holes of the hub (i.e., leading and trailing
> spokes)?
>
> Also, I'm planning to use 14-15-14 on the drive side and 15-16-15 on
> the NDS. Any opinions on that? I weigh 190 lbs.
>
> Thanks.
>
> --
> Art Harris
> Long Island, NY
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
--
Yellow Jersey, Ltd
http://www.yellowjersey.org
http://www.execpc.com/yellowje
Open every day since 1 April, 1971
Peter Headland
> thicker spokes is to make truing easier by reducing twist.
I dare to disagree. The twist issue is certainly worth considering, but
using different spoke thicknesses on the two sides of a rear wheel reduces
the sideways deflection of the rim at the road due to differential
shortening of the spokes on the two sides, which seems like a good idea to
me. More importantly, it also gives you a better safety margin of tension on
the non drive side spokes since the rim deflects less radially if you use
thicker drive side spokes. AIUI, the primary reason for using thinner spokes
(apart from a negligible weight saving) is to guard against cyclical or
impact-induced tension loss and corresponding increased fatigue in the
spoke, at the expense of increased rim flexing. This is not really a problem
for drive-side spokes on a 9sp wheel because they have to be seriously tight
anyway.
--
Peter Headland, Matrix Link, UK
Pe...@matrixlink.com
http://www.matrixlink.com/
Jobst Brandt
>> Use the same thinner spokes all around. The only reason to use
>> thicker spokes is to make truing easier by reducing twist.
> I dare to disagree. The twist issue is certainly worth considering,
> but using different spoke thicknesses on the two sides of a rear
> wheel reduces the sideways deflection of the rim at the road due to
> differential shortening of the spokes on the two sides, which seems
> like a good idea to me.
The disclaimer you append at the end reduces this to a preference,
rather than a functional benefit. I think you'll find that deflection
you perceive, hard to detect by any means outside a metrology lab.
> More importantly, it also gives you a better safety margin of
> tension on the non drive side spokes since the rim deflects less
> radially if you use thicker drive side spokes.
I take it you are theorizing on this, there being no evidence that
any of it occurs in use. Wheels with these hubs using the same spokes
left and right run well for the majority of riders. What you propose
has the ring of arguments for tying and soldering spoke crossings.
Jobst Brandt <jbr...@hpl.hp.com>
Izzy!
> left and right run well for the majority of riders. What you propose
> has the ring of arguments for tying and soldering spoke crossings.
I thought you might like to know that I built-up a wheel with
four different length spokes for the rear as an experiment.
The spokes that are tensioned under pedaling force were made
longer so the angle from the hub to the rim was shallower.
The wheel was indeed VERY stiff when hammering, but was somewhat
iffy feeling laterally, and you could hear the spokes rubbing on
each other as the rim deflected side to side. Simple heavy-duty
zip ties arranged not only to tie the spokes together but also to
tie the spoke *pairs* together solved it.
While it was a neat experiment, I don't think the benefits are worth
all the trouble. All the same it really looks interesting when the
bike's parked.
Mark Hickey
>Peter Headland writes:
>> More importantly, it also gives you a better safety margin of
>> tension on the non drive side spokes since the rim deflects less
>> radially if you use thicker drive side spokes.
>
>I take it you are theorizing on this, there being no evidence that
>any of it occurs in use. Wheels with these hubs using the same spokes
>left and right run well for the majority of riders. What you propose
>has the ring of arguments for tying and soldering spoke crossings.
Of course, tied and soldered wheels "run well for the majority of
riders" too.... (no, I'm not advocating it).
The way I've looked at it is...
1) There is an optimum tension for a spoke
2) The optimum tension for thinner spokes is lower
3) The tension on the non-drive side is lower
4) To obtain optimum tension on the non-drive side, you must either
over-tension the drive side, or use thinner spokes on the non-drive
side.
In practice, you'll gain more margin against loosening nipples by
using thinner, more compliant spokes on the NDS. Sure, a well-built
wheel with the same size spokes on both sides should work fine - but
there's really no downside to using thinner spokes (unless taken to an
extreme), and they're also lighter and more aerodynamic.
And they give you something to brag about next time you're hanging out
at a pre- or post-ride posing session.
Mark Hickey
Habanero Cycles
http://www.cynetfl.com/habanero/
Home of the $695 ti frame
Jobst Brandt
>> left and right run well for the majority of riders. What you
>> propose has the ring of arguments for tying and soldering spoke
>> crossings.
> I thought you might like to know that I built-up a wheel with four
> different length spokes for the rear as an experiment. The spokes
> that are tensioned under pedaling force were made longer so the
> angle from the hub to the rim was shallower.
Well, I didn't want to know but I am curious what spoke pattern you
used to allow for unequal tension. It seems you must have used cross
two for pushing and cross four for pulling spokes is it was 36 spokes
but even that would not make a large difference. You could have saved
yourself the effort had you been aware that all spokes on the right
side contribute to torque transmission whether pushing or pulling.
Again, these terms are with respect to tensioned spokes that vary
their tension in use.
> The wheel was indeed VERY stiff when hammering, but was somewhat
> iffy feeling laterally, and you could hear the spokes rubbing on
> each other as the rim deflected side to side. Simple heavy-duty
> zip ties arranged not only to tie the spokes together but also to
> tie the spoke *pairs* together solved it.
Maybe you could put some numbers on that. If you look at the graphs
in "the Bicycle Wheel" you'll notice that the displacements of rim to
hub (for a rider climbing a vertical wall) are so insignificantly
small that you could not feel them.
> While it was a neat experiment, I don't think the benefits are worth
> all the trouble. All the same it really looks interesting when the
> bike's parked.
I can well imagine but all you have accomplished is to build a wheel
with some of the spokes doing practically nothing because they are too
loose.
Jobst Brandt <jbr...@hpl.hp.com>
Jobst Brandt
>>> More importantly, it also gives you a better safety margin of
>>> tension on the non drive side spokes since the rim deflects less
>>> radially if you use thicker drive side spokes.
>> I take it you are theorizing on this, there being no evidence that
>> any of it occurs in use. Wheels with these hubs using the same
>> spokes left and right run well for the majority of riders. What
>> you propose has the ring of arguments for tying and soldering spoke
>> crossings.
> Of course, tied and soldered wheels "run well for the majority of
> riders" too.... (no, I'm not advocating it).
I believe they run well for all bicycle riders, in spite of throwing
salt over their shoulders.
> The way I've looked at it is...
> 1) There is an optimum tension for a spoke
> 2) The optimum tension for thinner spokes is lower
> 3) The tension on the non-drive side is lower
> 4) To obtain optimum tension on the non-drive side, you must either
> over-tension the drive side, or use thinner spokes on the non-drive
> side.
Well you missed on items 1 & 2. There is an optimum spoke tension for
a wheel or more accurately a rim unless you have too few spokes to
start with. Therefore, tension remains the same for thick or thin
spokes.
That makes item 4 incorrect as well because tension is not limited by
the spoke but by the rim.
> In practice, you'll gain more margin against loosening nipples by
> using thinner, more compliant spokes on the NDS. Sure, a well-built
> wheel with the same size spokes on both sides should work fine - but
> there's really no downside to using thinner spokes (unless taken to
> an extreme), and they're also lighter and more aerodynamic.
So what is it that is gained by using different thickness spokes?
> And they give you something to brag about next time you're hanging
> out at a pre- or post-ride posing session.
Disgusting!
Jobst Brandt <jbr...@hpl.hp.com>
Bob Mitke
>Mark Hickey wrote:
>> The way I've looked at it is...
>
>> 1) There is an optimum tension for a spoke
>> 2) The optimum tension for thinner spokes is lower
>> 3) The tension on the non-drive side is lower
>> 4) To obtain optimum tension on the non-drive side, you must either
>> over-tension the drive side, or use thinner spokes on the non-drive
>> side.
>
>Well you missed on items 1 & 2. There is an optimum spoke tension for
>a wheel or more accurately a rim unless you have too few spokes to
>start with. Therefore, tension remains the same for thick or thin
>spokes.
>
>That makes item 4 incorrect as well because tension is not limited by
>the spoke but by the rim.
Darnit Jobst, you beat me to it...
I will let you guys duke this one out...
My prediction is that Hickey puts his tail between his legs...
-Bob Mitke
Mark Hickey
>Mark Hickey writes:
>> 1) There is an optimum tension for a spoke
>> 2) The optimum tension for thinner spokes is lower
>> 3) The tension on the non-drive side is lower
>> 4) To obtain optimum tension on the non-drive side, you must either
>> over-tension the drive side, or use thinner spokes on the non-drive
>> side.
>
>Well you missed on items 1 & 2. There is an optimum spoke tension for
>a wheel or more accurately a rim unless you have too few spokes to
>start with. Therefore, tension remains the same for thick or thin
>spokes.
My point wasn't that you actually reach the "optimum tension" (since
as you point out, it's limited by the rim, not the spoke), but that
the (lower) tension on the NDS spokes will be closer to optimal if you
use a thinner spoke.
>That makes item 4 incorrect as well because tension is not limited by
>the spoke but by the rim.
>
>> In practice, you'll gain more margin against loosening nipples by
>> using thinner, more compliant spokes on the NDS. Sure, a well-built
>> wheel with the same size spokes on both sides should work fine - but
>> there's really no downside to using thinner spokes (unless taken to
>> an extreme), and they're also lighter and more aerodynamic.
>
>So what is it that is gained by using different thickness spokes?
For a given tension (which as you pointed out is constant regardless
of spoke diameter), a thinner spoke will have to be compressed more
before the nipple slackens. For the lower-tension NDS spokes, this
can result in a wheel that is less likely to require truing (though as
I said, a well-built wheel with the same size spokes shouldn't either
- there would just be a bit less "margin").
That, and the slight weight and aerodynamic benefits, of course.
>> And they give you something to brag about next time you're hanging
>> out at a pre- or post-ride posing session.
>
>Disgusting!
I hope the sarcasm was evident....
Art Harris
mhi...@cynetfl.com (Mark Hickey) wrote:
> jbr...@hpl.hp.com (Jobst Brandt) wrote:
> >So what is it that is gained by using different thickness spokes?
>
> For a given tension (which as you pointed out is constant regardless
> of spoke diameter), a thinner spoke will have to be compressed more
> before the nipple slackens. For the lower-tension NDS spokes, this
> can result in a wheel that is less likely to require truing (though as
> I said, a well-built wheel with the same size spokes shouldn't either
> - there would just be a bit less "margin").
Also, the tighter drive-side spokes will have less wind-up when using
thicker spokes (as Jobst pointed out at the beginning of this thread).
That is probably the strongest argument for using thicker spokes on the
right side.
If we think of spokes as springs, the extra "springyness" of thin
spokes can be a slight advantage on the left side (since it will make
them less likely to go slack). But remenber, there is 100% more tension
on the right side spokes, and the difference in "springyness" between
15 and 16 ga spokes is only about 12%.
So if there is such a thing as a "sweet spot" for a spoke within its
elastic range, we're still going to be below it on the left side.
Jobst Brandt
>>> 1) There is an optimum tension for a spoke
>>> 2) The optimum tension for thinner spokes is lower
>>> 3) The tension on the non-drive side is lower
>>> 4) To obtain optimum tension on the non-drive side, you must
>>> either over-tension the drive side, or use thinner spokes on
>>> the non-drive side.
>> Well you missed on items 1 & 2. There is an optimum spoke tension
>> for a wheel or more accurately a rim unless you have too few spokes
>> to start with. Therefore, tension remains the same for thick or
>> thin spokes.
> My point wasn't that you actually reach the "optimum tension" (since
> as you point out, it's limited by the rim, not the spoke), but that
> the (lower) tension on the NDS spokes will be closer to optimal if
> you use a thinner spoke.
What do you mean by "closer to optimal" when the thickness of the
spoke has no affect on that tension. It is given by the tension of
the spokes on the right and the total tension is limited by the rim.
I think this is stuck in a roundabout. We're back at the start.
Jobst Brandt <jbr...@hpl.hp.com>
Sheldon Brown
>
> >>> 1) There is an optimum tension for a spoke
> >>> 2) The optimum tension for thinner spokes is lower
> >>> 3) The tension on the non-drive side is lower
> >>> 4) To obtain optimum tension on the non-drive side, you must
> >>> either over-tension the drive side, or use thinner spokes on
> >>> the non-drive side.
>
> >> Well you missed on items 1 & 2. There is an optimum spoke tension
> >> for a wheel or more accurately a rim unless you have too few spokes
> >> to start with. Therefore, tension remains the same for thick or
> >> thin spokes.
>
> > My point wasn't that you actually reach the "optimum tension" (since
> > as you point out, it's limited by the rim, not the spoke), but that
> > the (lower) tension on the NDS spokes will be closer to optimal if
> > you use a thinner spoke.
> What do you mean by "closer to optimal" when the thickness of the
> spoke has no affect on that tension. It is given by the tension of
> the spokes on the right and the total tension is limited by the rim.
> I think this is stuck in a roundabout. We're back at the start.
I think Mark was referring not to optimal tension, but to optimal
tension/cross-sectional area. As you have yourself observed, thinner
spokes that stretch more under tension have more give, and can withstand
greater displacements without going slack.
Sheldon "They're Both Right" Brown
+----------------------------------------------------+
| A little inaccuracy sometimes saves tons of |
| explanation. --H.H.Munro ("Saki")(1870-1916) |
+----------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772, 617-244-1040 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com
Mark Hickey
>Mark Hickey writes:
>
>>>> 1) There is an optimum tension for a spoke
>>>> 2) The optimum tension for thinner spokes is lower
>>>> 3) The tension on the non-drive side is lower
>>>> 4) To obtain optimum tension on the non-drive side, you must
>>>> either over-tension the drive side, or use thinner spokes on
>>>> the non-drive side.
>
>>> Well you missed on items 1 & 2. There is an optimum spoke tension
>>> for a wheel or more accurately a rim unless you have too few spokes
>>> to start with. Therefore, tension remains the same for thick or
>>> thin spokes.
>
>> My point wasn't that you actually reach the "optimum tension" (since
>> as you point out, it's limited by the rim, not the spoke), but that
>> the (lower) tension on the NDS spokes will be closer to optimal if
>> you use a thinner spoke.
>
>What do you mean by "closer to optimal" when the thickness of the
>spoke has no affect on that tension. It is given by the tension of
>the spokes on the right and the total tension is limited by the rim.
I think the best way to put it is like this...
1) If a spoke is compressed until all pre-load is removed, the nipple
can unwind
2) At a given tension, a thinner spoke will have to be compressed
further before all the pre-load is removed - that is, a thinner spoke
will allow more deflection of the rim before the nipple can unwind.
>I think this is stuck in a roundabout. We're back at the start.
Think of it as newsgroup track racing....
Peter Headland
> > tension on the non drive side spokes since the rim deflects less
> > radially if you use thicker drive side spokes.
>
> I take it you are theorizing on this, there being no evidence that
> any of it occurs in use.
I think you didn't mean to say "any of it", since it is quite clear that a
thicker spoke loses tension faster with reduction in length and hence that
rim deflection is lower with thicker spokes. So you seem simply to disagree
that this reduced deflection provides any benefit to the non-drive side
spokes.
You are well-documented here and in your book as claiming that it is
desirable for all spokes in a wheel to have equal tension. What is the
benefit of this, please? If it is for the benefit of the spokes, and given
that we cannot have equal tension between the two sides of a dished rear
wheel, we can achieve the same benefits for the spokes by using thinner
spokes on the lower tension side and thus ensuring that the load/x-section
is nearer to that on the right.
No-one is disputing that using the same spokes on boths sides works
acceptably. That doesn't mean that there is no benefit to using thinner
spokes on the non-drive side purely from the POV of those spokes' service
life. But it may be that achieving this with thicker spokes on the drive
side has sufficient disadvantages that there is no net gain.
Thicker drive-side spokes mean better lateral stiffness and easier building.
They may also mean poorer fatigue life for the drive-side spokes.
NotOutRiding
>Thicker drive-side spokes mean better lateral stiffness and easier building.
>They may also mean poorer fatigue life for the drive-side spokes.
You may have something here. I have noticed that using thicker drive side
spokes seems to make for spoke breakages where none were happening before in
wheels I had built using the same methods that I have used since I started to
build wheels (prompted by firstly a series of wheelbuilding articles by Eric
Hejertberg in the 80's in Bicycling, and secondly by Jobsts book). Going
lighter on the NGS seemed to make sense, so I built some wheels that way, but
those wheels have been nothing but problem children.
Anyone care to comment?
Max.
Jobst Brandt
>>> More importantly, it also gives you a better safety margin of
>>> tension on the non drive side spokes since the rim deflects less
>>> radially if you use thicker drive side spokes.
>> I take it you are theorizing on this, there being no evidence that
>> any of it occurs in use.
> I think you didn't mean to say "any of it", since it is quite clear
> that a thicker spoke loses tension faster with reduction in length
> and hence that rim deflection is lower with thicker spokes. So you
> seem simply to disagree that this reduced deflection provides any
> benefit to the non-drive side spokes.
I don't disagree with the concept that many thin spokes is better than
a few thick spokes for stress distribution and durability of a wheel.
However the claims about what different thickness spokes do for the
left and right sides of a rear wheel are not as claimed. It may be a
case of poorly stated explanation of results, but the way it stands, it
does not make sense.
> You are well-documented here and in your book as claiming that it is
> desirable for all spokes in a wheel to have equal tension. What is
> the benefit of this, please?
If you go to the trouble of citing sentences from the book, please >
read all of it. The meaning of this and its benefit is explained at
length. I don't intend to rewrite the book here.
> No-one is disputing that using the same spokes on both sides works
> acceptably. That doesn't mean that there is no benefit to using
> thinner spokes on the non-drive side purely from the POV of those
> spokes' service life. But it may be that achieving this with
> thicker spokes on the drive side has sufficient disadvantages that
> there is no net gain.
As I said this is all theoretical, the practical side being more important
assuming it is not taken to extremes... as many wheels are these days as
in Rolf, Shimano 7700, etc.
> Thicker drive-side spokes mean better lateral stiffness and easier building.
> They may also mean poorer fatigue life for the drive-side spokes.
Lateral stiffness is not a primary criterion for a wheel. If the
wheel is strong enough to take the beating radially, it is strong
enough laterally. Of course this goes for a given hub and that it has
adequate flange spacing to start with. As I said, there are many
unreasonable wheels offered today and arguing about odd spoke
combinations is just so much rearranging deck chairs on the Titanic.
Jobst Brandt <jbr...@hpl.hp.com>
A Muzi
spokes break, up to a point. I'll defer to Jobst for further comment.
NotOutRiding wrote:
--
Peter Headland
> > desirable for all spokes in a wheel to have equal tension. What is
> > the benefit of this, please?
>
> If you go to the trouble of citing sentences from the book, please >
> read all of it. The meaning of this and its benefit is explained at
> length. I don't intend to rewrite the book here.
Well, at risk of distressing you, I don't actually keep your book here in my
office nor have I committed every word to memory verbatim. And when I looked
for it at home last night I could not find it (OK, we are untidy folk, I
confess). In any case, others reading this thread might not have the book at
all and would benefit from a brief answer.
My contention remains that on a 9sp wheel with the resultant heavy dishing
and high drive-side spoke tension one is well advised to compromise between
very thin spokes which are best for durability, and thicker ones (plain 2mm
or 2.0/1.8 double butted) which are easier to build with due to reduced
wind-up. On the non-drive side one should use the thinnest spokes available.
Do you have any good arguments against this contention beyond the mere claim
it is "unnecessary" (with which I disagree for the reasons stated above)?
Given one has to purchase spokes of some kind to build a new wheel, I simply
do not see why one should not purchase spokes of differing thicknesses. But
if you feel that a genuinely *inferior* wheel would result I would like to
know why.