wheel building question



F

Frank Knox

Guest
I am going to build wheels with 36h Campagnolo Record large flange hubs made
in 1973. I plan to lace them in a cross 3 pattern to Open Pro rims.

The hubs were originally laced in a cross 4 pattern. The outbound spokes
touch the heads of inbound spokes.

Is there any *valid* reason this was done, or that I should do so now?
 
The only valid reason for "overcrossing" is to use a longer spoke. This is only valid when you don't have correct length spokes. 3 cross would be stronger and yes, you can go ahead and lace 3 cross even though the wheels were laced 4 cross.
 
Frank Knox writes:

> I am going to build wheels with 36h Campagnolo Record large flange
> hubs made in 1973. I plan to lace them in a cross 3 pattern to Open
> Pro rims.


> The hubs were originally laced in a cross 4 pattern. The outbound
> spokes touch the heads of inbound spokes.


> Is there any *valid* reason this was done, or that I should do so
> now?


....only to avoid double deformation of the spoke holes in the flanges.
Re-spoking with a different pattern has caused flange failures of
which I have examples. The reason for high flange hubs was for track
riding where spokes could be replaced without removing sprockets,
spoke failure being common in those times. That torque was not a
problem was unknown at that time and was commonly believed to be the
reason for large flange hubs. That track bicycles where were ridden
by the strongest and most muscular riders was apparent. What was
overlooked was that they rode big gears with tiny rear sprockets while
road riders used sprockets twice as large and caused much more and
more repetitive high torque loads.

Jobst Brandt
[email protected]
 
Weisse Luft wrote:

> The only valid reason for "overcrossing" is to use a longer spoke. This
> is only valid when you don't have correct length spokes. 3 cross would
> be stronger and yes, you can go ahead and lace 3 cross even though the
> wheels were laced 4 cross.


A couple of questions:

Why is 3 cross stronger than 4 cross? No obvious reason springs to
mind.

Shouldn't the hub be laced the same way it was before, to avoid
additional stresses on the hub that might make it fail at the spoke
holes?
--
terry morse Palo Alto, CA http://bike.terrymorse.com/
 
<[email protected]> wrote in message
news:p[email protected]...
> Frank Knox writes:
>
> > I am going to build wheels with 36h Campagnolo Record large flange
> > hubs made in 1973. I plan to lace them in a cross 3 pattern to Open
> > Pro rims.

>
> > The hubs were originally laced in a cross 4 pattern. The outbound
> > spokes touch the heads of inbound spokes.

>
> > Is there any *valid* reason this was done, or that I should do so
> > now?

>
> ...only to avoid double deformation of the spoke holes in the flanges.
> Re-spoking with a different pattern has caused flange failures of
> which I have examples. The reason for high flange hubs was for track
> riding where spokes could be replaced without removing sprockets,
> spoke failure being common in those times. That torque was not a
> problem was unknown at that time and was commonly believed to be the
> reason for large flange hubs. That track bicycles where were ridden
> by the strongest and most muscular riders was apparent. What was
> overlooked was that they rode big gears with tiny rear sprockets while
> road riders used sprockets twice as large and caused much more and
> more repetitive high torque loads.
>
> Jobst Brandt
> [email protected]



I have seen the spoke hole deformations you mentioned in other hubs but not
these.
The spokes I removed were butted 2.0-1.6 and were not tensioned nearly as
much as I learned to do in your book.
Since I have removed the spokes and cannot detect from looking at the hubs
how they were laced, I hope that I can get away with a 3x.
Thank you for your advice.
 
Frank Knox writes:

>>> I am going to build wheels with 36h Campagnolo Record large flange
>>> hubs made in 1973. I plan to lace them in a cross 3 pattern to
>>> Open Pro rims.


>>> The hubs were originally laced in a cross 4 pattern. The outbound
>>> spokes touch the heads of inbound spokes.


>>> Is there any *valid* reason this was done, or that I should do so
>>> now?


>> ...only to avoid double deformation of the spoke holes in the
>> flanges. Re-spoking with a different pattern has caused flange
>> failures of which I have examples. The reason for high flange hubs
>> was for track riding where spokes could be replaced without
>> removing sprockets, spoke failure being common in those times.
>> That torque was not a problem was unknown at that time and was
>> commonly believed to be the reason for large flange hubs. That
>> track bicycles where were ridden by the strongest and most muscular
>> riders was apparent. What was overlooked was that they rode big
>> gears with tiny rear sprockets while road riders used sprockets
>> twice as large and caused much more and more repetitive high torque
>> loads.


> I have seen the spoke hole deformations you mentioned in other hubs
> but not these. The spokes I removed were butted 2.0-1.6 and were
> not tensioned nearly as much as I learned to do in your book. Since
> I have removed the spokes and cannot detect from looking at the hubs
> how they were laced, I hope that I can get away with a 3x.


That's great. I can't imagine anyone riding much with a wheel that
loose but then there are lots of marginally used wheels. I wish you
good wheels and good rides.

Jobst Brandt
[email protected]
 
[email protected] wrote:

> I wish you good wheels and good rides.


OK, first Mr. Peanut and now this.

Who are you and what have you done with Jobst?!?
 
Frank-<< I am going to build wheels with 36h Campagnolo Record large flange
hubs made
in 1973. I plan to lace them in a cross 3 pattern to Open Pro rims.

The hubs were originally laced in a cross 4 pattern. The outbound spokes
touch the heads of inbound spokes.

Is there any *valid* reason this was done, or that I should do so now?
>><BR><BR>



I answer-no and no. lace 3 cross with the spokes the same orientation, that is
head in/out/pulling the same.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"