Symetrical Hub Drilling

Andy Masia said:

I am building a rear wheel using an old Shimano 600, 32 hole, hub
and Mavic GL rim. The drilling on the hub is symmetrical, in that
holes in the left flange are directly opposite holes in the right.
They are not out of phase by 1/2 hole spacing. Each time I lace up
the wheel I find that every other spoke is tight, the remainder
loose on both the left and right sides. All other hubs with which I
have experience are drilled so the holes on left and right flanges
are out of phase by 1/2 hole spacing distance. Does anybody have
any experience assembling such a symmetrical hub?

Is this a new or used hub. I can't imagine this error occurring in
manufacture but I suppose it is possible. Since rim holes are half
way between each other, hub holes need to be likewise. If this is a
used hub, then maybe someone spoked it up wrong and tightened the
spokes. That would twist the center of the "spool" and can make the
holes as you describe. This would be apparent by a twist in any
writing on the hub shaft.

I have seen people damage hubs this way and they were unrecoverable
because they were no longer straight on their axis.

Jobst Brandt
[email hidden]

[email hidden] wrote in message news:<[email hidden]>...

Quoted message said:

Andy Masia said:

I am building a rear wheel using an old Shimano 600, 32 hole, hub
and Mavic GL rim. The drilling on the hub is symmetrical, in that
holes in the left flange are directly opposite holes in the right.
They are not out of phase by 1/2 hole spacing. Each time I lace up
the wheel I find that every other spoke is tight, the remainder
loose on both the left and right sides. All other hubs with which I
have experience are drilled so the holes on left and right flanges
are out of phase by 1/2 hole spacing distance. Does anybody have
any experience assembling such a symmetrical hub?

Is this a new or used hub. I can't imagine this error occurring in
manufacture but I suppose it is possible. Since rim holes are half
way between each other, hub holes need to be likewise. If this is a
used hub, then maybe someone spoked it up wrong and tightened the
spokes. That would twist the center of the "spool" and can make the
holes as you describe. This would be apparent by a twist in any
writing on the hub shaft.

I have seen people damage hubs this way and they were unrecoverable
because they were no longer straight on their axis.

Jobst Brandt
[email hidden]

Thanks for your comments, Jobst. I have followed the lacing
procedures on pages 90 - 100 of your book on several previous
occasions and, each time, easily gotten it right. That is why this
case is so confusing.

To answer your questions:

1) This is a used hub. I bought a used, fully built, wheel using this
hub last summer and I rode it for at least a thousand miles during
which it stayed true. A minor accident found it well out of true. I
trued it, but found the resulting spoke tensions to be very uneven so
I decided to replace the apparently bent rim and all of the spokes.
Once I detensioned the old spokes and removed the rim I found that it
was, indeed, badly bent from the crash. Unfortunately I did not make
careful note of the spoke pattern or any possible anomalies. It
seemed on casual inspection to be a conventional 3 cross pattern and I
thought nothing more of it.

2) No the hub does not seem to bent, twisted, or distorted in any
way.

I followed your instructions for lacing twice, and each time ended up
with alternate spokes tight and loose on both sides. Both times, I
caught the error prior to truing and full tensioning and then
disassembled the entire kit. I then started to follow the more
complex procedure in the Barnett book. This is where, when marking
the positions for starting spokes on both flanges, I discovered that
the holes were directly opposing instead of being staggered.

I am, of course, confused because the hub was previously built into an
adequate and serviceable wheel with spokes of reasonable and matched
length. So, I assumed that there must be a way to lace this hub. On
the other hand, this seems contrary to the fact, as you point out in
your post, that as the holes in the rim are offset, so must be the
holes in the hub.

Andy Masia
[email hidden]

Andy Masia said:

I am, of course, confused because the hub was previously built into an
adequate and serviceable wheel with spokes of reasonable and matched
length. So, I assumed that there must be a way to lace this hub. On
the other hand, this seems contrary to the fact, as you point out in
your post, that as the holes in the rim are offset, so must be the
holes in the hub.

Unfortunately the evidence is gone. I can't imagine how the hub got
that way and how the previous wheel was built.

Jobst Brandt
[email hidden]

Andy Masia said:

[email hidden] wrote in message news:<[email hidden]>...

Quoted message said:

Andy Masia said:

I am building a rear wheel using an old Shimano 600, 32 hole, hub
and Mavic GL rim. The drilling on the hub is symmetrical, in that
holes in the left flange are directly opposite holes in the right.
They are not out of phase by 1/2 hole spacing. Each time I lace up
the wheel I find that every other spoke is tight, the remainder
loose on both the left and right sides. All other hubs with which I
have experience are drilled so the holes on left and right flanges
are out of phase by 1/2 hole spacing distance. Does anybody have
any experience assembling such a symmetrical hub?

Is this a new or used hub. I can't imagine this error occurring in
manufacture but I suppose it is possible. Since rim holes are half
way between each other, hub holes need to be likewise. If this is a
used hub, then maybe someone spoked it up wrong and tightened the
spokes. That would twist the center of the "spool" and can make the
holes as you describe. This would be apparent by a twist in any
writing on the hub shaft.

I have seen people damage hubs this way and they were unrecoverable
because they were no longer straight on their axis.

Jobst Brandt
[email hidden]

Thanks for your comments, Jobst. I have followed the lacing
procedures on pages 90 - 100 of your book on several previous
occasions and, each time, easily gotten it right. That is why this
case is so confusing.

To answer your questions:

1) This is a used hub. I bought a used, fully built, wheel using this
hub last summer and I rode it for at least a thousand miles during
which it stayed true. A minor accident found it well out of true. I
trued it, but found the resulting spoke tensions to be very uneven so
I decided to replace the apparently bent rim and all of the spokes.
Once I detensioned the old spokes and removed the rim I found that it
was, indeed, badly bent from the crash. Unfortunately I did not make
careful note of the spoke pattern or any possible anomalies. It
seemed on casual inspection to be a conventional 3 cross pattern and I
thought nothing more of it.

2) No the hub does not seem to bent, twisted, or distorted in any
way.

I followed your instructions for lacing twice, and each time ended up
with alternate spokes tight and loose on both sides. Both times, I
caught the error prior to truing and full tensioning and then
disassembled the entire kit. I then started to follow the more
complex procedure in the Barnett book. This is where, when marking
the positions for starting spokes on both flanges, I discovered that
the holes were directly opposing instead of being staggered.

I am, of course, confused because the hub was previously built into an
adequate and serviceable wheel with spokes of reasonable and matched
length. So, I assumed that there must be a way to lace this hub. On
the other hand, this seems contrary to the fact, as you point out in
your post, that as the holes in the rim are offset, so must be the
holes in the hub.

Andy Masia
[email hidden]

it's unlikely, but not impossible that the hub somehow was mispositioned
when originally drilled. i have a n.o.s. campy super record hub drilled
exactly the same as yours - it's even got some uneven spacing between
some of the holes!!! seems it was a bad monday morning for some one.

for the cost of a new hub, it's really not worth trying to make
something of this piece. just keep it as a coffee table talking point
and build your new wheel around a discounted 7700 hub or something like
that.

It sounds like this unfortunate hub had its right hand spokes (but not its
left) cut out before the freewheel was removed, then the hub got twisted when
breaking the freewheel loose.
Mark Pace

On 5 Oct 2004 08:06:12 -0700, [email hidden] (Andy Masia)

Quoted message said:

Quoted message said:

Quoted message said:

I am building a rear wheel using an old Shimano 600, 32 hole, hub
and Mavic GL rim. The drilling on the hub is symmetrical, in that
holes in the left flange are directly opposite holes in the right.
They are not out of phase by 1/2 hole spacing.

My guess is that this Shimano 600 hub is one of the ones that were
bonded together in two halves: the left flange and left part of the
"spool" in one piece, and the right flange and right part of the
"spool" in a second piece. The joint is neatly hidden next to the
decal, IIRC.

I'd first consider trying to twist it back into phase. Maybe even
disbond it and re-bond. If that doesn't work, then I'd take the
others' advice and use a different hub.

[email hidden] (Andy Masia) wrote in message news:<[email hidden]>...

Quoted message said:

I am building a raear wheel using an old Shimano 600, 32 hole, hub and
Mavic GL rim. The drilling on the hub is symetrical, in that holes
in the left flange are direcltly opposite holes in the right. They
are not out of phase by 1/2 hole spacing. Each time I lace up the
wheel I find that every other spoke is tight, the remainder loose on
both the left and right sides. All other hubs with which I have
experience are drilled so the holes on left and right flanges are out
of phase by 1/2 hole spacing distance. Does anybody have any
experience assembling such a symetrical hub?

Thanks for your help.

-Andy Masia

Shimano sells wheels which are designed the way you describe such as:
http://bike.shimano.com/Wheels/Wheels_-_Road/componenttemplate.asp?partnumber=WH-7701

If you want to use this hub with a mismatched rim, avoid putting large
torque through the hub.

Consider lacing the drive side conventionally, then lacing the
left side:
repeat 5 times: (leading "cross 1.5", lagging "cross 1.5", empty)
lace the sixtenth spoke near radial and enjoy reduced tension
mismatch over having torque from all 16 having a "cross bias".
This would work pretty well if it had been 36 hole.

Note that using "cross .5" would give spoke lengths closer
to what you use for the odd sixteenth spoke and would still
have some left side cross as opposed to full radial left side.

Using 11 of the 16 left side spoke should still keep left side
tension reasonable (left side tension will be higher than with
16 spokes but should not yet be a threat to the spoke strength).

It'd be better to match the rim to a conventional hub.

Enjoy, Ed.

On 10/6/04 12:03 AM, in article [email hidden], "jim

beam said:

<snip>

for the cost of a new hub, it's really not worth trying to make
something of this piece. just keep it as a coffee table talking point...

For that matter, while you're putting it on your coffee table, make a
candlestick out of it..

Y.