WheelBuilding Q's: Campy hub Weight Limit, Reusing Rims, etc

[bigsky]

I am rebuilding my road bike with Campy drivetrain.

First question: Why does Campagnolo state a weight limit to riders on
Veloce hubs as 180 lbs? Any idea what failure mode is expected (axle or
flange fractures)? At 220, I exceed that limit. The technical info
states if your over 180lbs to "confirm with your mechanic that your
Campagnolo component are suitable for your use". Could a certain lacing
pattern compensate? I am considering staying with a 3/2 cross on the
rear wheel (32 hole).

Second Question: Any problem reusing an old rim? Its a Mavic Rimtec
marked both as 190H and 190FB. I build the wheel back in 1991, it been
kept in air conditioned storage since 1993, and has low milage (~1500)
with no accidents or problems. Any historical data on life (shelf) of
aluminum rims?

Final Question: Campagnolo does not list dimensions on the Veloce hub
on its website. Furthermore, there does not seem to be any data
available on the many spoke calculator sites I've seen through this
group. Anyone know where I can find the data online?

Any guidance, pointers, or insights into the above questions is appreciated.

Thanks,
bigsky

 

[[email protected]]

Someone writes:

> I am rebuilding my road bike with Campy drivetrain.

> First question: Why does Campagnolo state a weight limit to riders
> on Veloce hubs as 180 lbs? Any idea what failure mode is expected
> (axle or flange fractures)? At 220, I exceed that limit. The
> technical info states if your over 180lbs to "confirm with your
> mechanic that your Campagnolo component are suitable for your use".
> Could a certain lacing pattern compensate? I am considering staying
> with a 3/2 cross on the rear wheel (32 hole).

There are tow aspects to hub durability not related to axle and
bearings that affect the flanges. One is maximum spoke tension that
could be specified in the restriction. The other is tension variation
in use. I believe the second effect, which can cause fatigue failure
between spoke holes in the flange and subsequent release of the
spokes, should be designed out. That is the flanges should be
designed to take cyclic loads from zero to maximum spoke tension.

My reason for this approach is that regardless of rider weight, cyclic
loading can span the entire range between maximum tension and slack.
A 150 pound rider who rides on rough roads will have the same effect
as a heavier on since spoke tension when riding over bumps cannot go
lower than zero.

> Second Question: Any problem reusing an old rim? Its a Mavic Rimtec
> marked both as 190H and 190FB. I build the wheel back in 1991, it
> been kept in air conditioned storage since 1993, and has low mileage
> (~1500) with no accidents or problems. Any historical data on life
> (shelf) of aluminum rims?

Don't worry about the age of the rim even if it was in an unheated
garage for years. As long as it isn't corroded it will be as good as
it was when first stored. Whether that rim is any good is another
question. I know nothing about that rim so I can't help you there.

> Final Question: Campagnolo does not list dimensions on the Veloce
> hub on its website. Furthermore, there does not seem to be any data
> available on the many spoke calculator sites I've seen through this
> group. Anyone know where I can find the data online?

> Any guidance, pointers, or insights into the above questions is
> appreciated.

You can measure the diameter of the spoke hole pattern and flange
spacing at your local bicycle shop where there are probably a few
wheels with those hubs.

Jobst Brandt
[email protected]

 

[David L. Johnson]

On Sun, 20 Feb 2005 19:22:36 +0000, bigsky wrote:

> I am rebuilding my road bike with Campy drivetrain.
>
> First question: Why does Campagnolo state a weight limit to riders on
> Veloce hubs as 180 lbs? Any idea what failure mode is expected (axle or
> flange fractures)? At 220, I exceed that limit. The technical info
> states if your over 180lbs to "confirm with your mechanic that your
> Campagnolo component are suitable for your use".

They seem to be covering their posteriors with that. I would not
worry; lots of us have been using Campy hubs of various sorts for
many years, exceeding that weight limit, without trouble.

Could a certain
lacing
> pattern compensate? I am considering staying with a 3/2 cross on the
> rear wheel (32 hole).

I would recommend 3x both sides for 32 spoke wheels.
>
> Second Question: Any problem reusing an old rim?

None at all, assuming there is no visible corrosion.

> Final Question: Campagnolo does not list dimensions on the Veloce hub
> on its website. Furthermore, there does not seem to be any data
> available on the many spoke calculator sites I've seen through this
> group. Anyone know where I can find the data online?

Damon Rinard's spocalc spreadsheet has the following:

S, mm dL, mm WL, mm dR, mm WR, mm F/R cogs OLD, mm Hub
2.4 44.0 36.5 44.0 16.7 R 9 130 Campagnolo 1999+ Athena, Veloce, Mirage
>
That is, the flange thickness is 2.4mmm left hole diameter is 44mm,
distance from centerline to left flange is 36.5mm, etc. Even if your hub
is older, I'd imagine the numbers still apply.

--

David L. Johnson

__o | As far as the laws of mathematics refer to reality, they are not
_`\(,_ | certain, and as far as they are certain, they do not refer to
(_)/ (_) | reality. -- Albert Einstein

 

[[email protected]]

Paul Kopit writes:

>> I would recommend 3x both sides for 32 spoke wheels.

> What would be different if the OP used 3x2 cross?

Nearly fully tangential spoking, that in which the spokes leave the
flange hole circle in a tangent manner, puts the flange in compression
between spokes and loads the flange in shear for vertical loads. An
example would be hooking index fingers together an pulling to simulate
a pair of spokes in adjacent holes. They generate practically no
radial load on the flange, the tensile load that causes break-outs.

Pedaling torque is not a significant load as is shown in graphs in
"the Bicycle Wheel" although this is the reason often given for
tangential spoking. Flanges break occasionally and a picture recently
offered here was typical of flange break-out with less than tangential
spokes. It is for this reason that I use 36x4 spoking on low flange
hubs. High flange hubs present problems at spoke threads when spoked
tangentially, but then large flanges don't break out as easily because
the flange holes are farther apart.

Jobst Brandt
[email protected]

 

[dianne_1234]

On Sun, 20 Feb 2005 21:28:54 GMT, Paul Kopit
<[email protected]> wrote:

>On Sun, 20 Feb 2005 15:03:39 -0500, "David L. Johnson"
><[email protected]> wrote:
>
>>I would recommend 3x both sides for 32 spoke wheels.
>
>What would be different if the OP used 3x2 cross?

Among other effects, the 2 cross side would have a larger bracing
angle (and lower spoke tension) than if it were built 3 cross.

If the 2 cross side is on the left, 3 cross would be better because
the left already has too much bracing angle.

If the 2 cross side is on the right, the increased bracing angle would
benefit wheel (lateral) strength, but the derailleur might hit the
spokes when the chain is in the largest cog.

For an illustration of how 2 cross increases the bracing angle
compared to 3 cross, see
http://www.geocities.com/dianne_1234/bikes/2x3x.htm

 

[A Muzi]

bigsky wrote:
> I am rebuilding my road bike with Campy drivetrain.
>
> First question: Why does Campagnolo state a weight limit to riders on
> Veloce hubs as 180 lbs? Any idea what failure mode is expected (axle or
> flange fractures)? At 220, I exceed that limit. The technical info
> states if your over 180lbs to "confirm with your mechanic that your
> Campagnolo component are suitable for your use". Could a certain lacing
> pattern compensate? I am considering staying with a 3/2 cross on the
> rear wheel (32 hole).
>
> Second Question: Any problem reusing an old rim? Its a Mavic Rimtec
> marked both as 190H and 190FB. I build the wheel back in 1991, it been
> kept in air conditioned storage since 1993, and has low milage (~1500)
> with no accidents or problems. Any historical data on life (shelf) of
> aluminum rims?
>
> Final Question: Campagnolo does not list dimensions on the Veloce hub
> on its website. Furthermore, there does not seem to be any data
> available on the many spoke calculator sites I've seen through this
> group. Anyone know where I can find the data online?
>
> Any guidance, pointers, or insights into the above questions is
> appreciated.

At 220Lb, we would have built your wheel 36h with an
asymmetric rim for more even tension, 14gDBSS and brass
nipples, 3-cross.

Since you own the hub already, I'd build an asymmetric 32h
rim such as Velocity's Aerohead OC and 3-cross it with 293/5
butted 14g spokes about 100Kg.

Your rim is as good as it was when you put it away so use it
for a front if it is round.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

 

[A Muzi]

> On Sun, 20 Feb 2005 15:03:39 -0500, "David L. Johnson"
> <[email protected]> wrote:
>>I would recommend 3x both sides for 32 spoke wheels.

Paul Kopit wrote:
> What would be different if the OP used 3x2 cross?

Probably not much, but where's any gain? Shorter spokes
don't work any better than longer ones.

At extreme cases, what would you say about 3cross-1cross if
shorter spokes don't matter? Or even 3cross-0cross
(radial), shorter still . Would that be better in any way?

I'm not saying he _shouldn't_ if he thinks it pretty but I
don't see what's any better about it.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

 

[Paul Kopit]

On Sun, 20 Feb 2005 21:56:13 GMT, [email protected]
wrote:

>Pedaling torque is not a significant load as is shown in graphs in
>"the Bicycle Wheel" although this is the reason often given for
>tangential spoking. Flanges break occasionally and a picture recently
>offered here was typical of flange break-out with less than tangential
>spokes. It is for this reason that I use 36x4 spoking on low flange
>hubs. High flange hubs present problems at spoke threads when spoked
>tangentially, but then large flanges don't break out as easily because
>the flange holes are farther apart.

In my limited experience, flanges on both 28 and 32 spoke wheels don't
break out on the non drive side of the rim and 2x and 3x doesn't seem
to matter.

I keep a limited number of sizes of spokes, 289-297 and I'll sometimes
select spoke crossing based on what spokes I have available.

 

[Paul Kopit]

On Sun, 20 Feb 2005 21:18:40 -0600, A Muzi <[email protected]>
wrote:

>At extreme cases, what would you say about 3cross-1cross if
>shorter spokes don't matter? Or even 3cross-0cross
>(radial), shorter still . Would that be better in any way?
>
>I'm not saying he _shouldn't_ if he thinks it pretty but I
>don't see what's any better about it.
>--

I'm not a pro but do buy spokes in boxes of 100. I keep the range
small, 289-297 and sometimes select the crosses based on the spokes I
have. The only advantage 2x has is that it is easier to get in with a
rag to clean and polish the hub on a built wheel.

 

[A Muzi]

Paul Kopit wrote:

> The only advantage 2x has is that it is easier to get in with a
> rag to clean and polish the hub on a built wheel.

!!!
That was unexpected. Now there are little coffee droplets
all over my keyboard.

Best reason so far!
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

 

[bigsky]

A Muzi wrote:
>> On Sun, 20 Feb 2005 15:03:39 -0500, "David L. Johnson"
>> <[email protected]> wrote:
>
> >>I would recommend 3x both sides for 32 spoke wheels.
>
> Paul Kopit wrote:
>
>> What would be different if the OP used 3x2 cross?
>
>
> Probably not much, but where's any gain? Shorter spokes don't work any
> better than longer ones.
>
> At extreme cases, what would you say about 3cross-1cross if shorter
> spokes don't matter? Or even 3cross-0cross (radial), shorter still .
> Would that be better in any way?
>
> I'm not saying he _shouldn't_ if he thinks it pretty but I don't see
> what's any better about it.

As anyone who has seen my gear, pretty has nothing to do with it. In
fact, I was working from a suggestion on one of the wheelbuilding
websites that a 3 non-drive/2 drive side lacing pattern evens out the
spoke tension (seems reasonable). I would consider the 3/radial pattern
suggested on Sheldon's website, but Campagnolo forbids radial lacing on
their hubs.

bigsky

 

[bigsky]

A Muzi wrote:

....
>
> At 220Lb, we would have built your wheel 36h with an asymmetric rim for
> more even tension, 14gDBSS and brass nipples, 3-cross.

I thought that the number of spokes would increase the weight limit, but
Campagnolo does not specify a different weight limit for 32 vs 36 spoke
hubs. By their data, 180 lbs is still the limit.

>
> Since you own the hub already, I'd build an asymmetric 32h rim such as
> Velocity's Aerohead OC and 3-cross it with 293/5 butted 14g spokes about
> 100Kg.
>
> Your rim is as good as it was when you put it away so use it for a front
> if it is round.

 

[dianne_1234]

On Tue, 22 Feb 2005 05:34:58 GMT, bigsky <[email protected]>
wrote:

>In
>fact, I was working from a suggestion on one of the wheelbuilding
>websites that a 3 non-drive/2 drive side lacing pattern evens out the
>spoke tension (seems reasonable).

Yes, that's more sensible than the more common 3x right and 2x left.
If the spokes will still clear your derailleur (not at all certain
without checking) then I'd go for it if I were you.