Interesting lacing on a wheel

[Black Dog]

Well, I thought I had seen every way to lace a wheel. I knew that this was possible but never seen it done. 32 hole hub on a 24 hole rim.

[Columbus SLX]

I think that pattern is called Crow’s Foot, but never seen it with skipped holes!

[ultraman6970]

Well the guy made it work :D the wheel is actually ok in the stiffness dept?

[dgauthier]

I'd be curious what the wheel builders on this forum have to say about skipping holes.

Obviously it's sub-optimal (at the very least, a 24 hole hub would have a stronger flange because it has fewer drillings), but I'm curious if a wheel builder would say "NEVER do this!" or "yuck, but it's fine".

Applying 24 spoke loads on a 32 hole flange seems like a great way to make a flange fail prematurely...

[GOTHBROOKS]

i know a few old timers who have race day wheels like this. also with a 32h rim and with the empty spoke holes taped off.
they are also too fat to ride their hi-e hubs.

[bob_in_pa]

I think that pattern is called Crow’s Foot, but never seen it with skipped holes!

I believe you’re right - crows foot lacing. I never built or ridden a wheel so laced but I’ve always thought it was a form over function kind of thing. I don’t know of any reason other than looks to build a wheel like that. Not saying it’s bad but not my cup of tea.
I wonder what kind of rim was used?

-Bob

[muz]

The practical difficulty of a pattern like this is that it requires many different spoke lengths. I am curious if any shortcuts were taken, like are all the spokes the correct length?

[Mark McM]

I'd be curious what the wheel builders on this forum have to say about skipping holes.

Obviously it's sub-optimal (at the very least, a 24 hole hub would have a stronger flange because it has fewer drillings), but I'm curious if a wheel builder would say "NEVER do this!" or "yuck, but it's fine".

Applying 24 spoke loads on a 32 hole flange seems like a great way to make a flange fail prematurely...

Yes, that's a crow's foot pattern. Crow's foot patterns can only be done on wheels with a multiple of 6 spokes (36, 24, 18, 12).

Skipping holes shouldn't be much of a problem on a hub with strong flanges. A very common way to do triplet lacing (also called 2:1 lacing) is to use a 24 hole rim and a 32 hole hub, and skip every other hole on the non-driveside.

There is a problem with the lacing on this particular wheel, if it indeed does use a 24 hole rim, although it may not seem obvious. Most rims have equally spaced holes. The spoke holes on opposite flanges are offset, so that that holes on one flange line up with the even number holes on the rim, and the spokes on the other flange line up with the odd number holes. If you use a rim and hub with a different number of holes, or if you skip holes on the rim or the hub, you can lose the alignment between the rim and flange holes. This becomes a problem with crossed spokes, because the tension on spokes at an angle to the flange causes torque on the flange. Spokes typically have more than 200 lb. of static tension, and a whole set of angled spokes can generate a very large torsion. When you have symetrically laced spokes with equal leading and trailing angles, all the torsions balance out, and you don't have a net torsion between flanges. But when the asymmetry and a mis-alignment between the flanges, it can actually break the the hub (particularly if it has a narrow spool between the flanges, like this wheel does.

There are ways to avoid the asymmetry problem, if you skip holes in the correct sequence, or if you skip the appropriate holes in the rim as well. One example is given above, with triplet lacing of a 24 hole rim on a 32 hole hub. For the crow's foot wheel above, one way to solve the asymmetry problem would be to use a 32 hole rim, and skip the holes in the rim corresponding to the slipped holes at the hub. With a stiff enough rim, that would actually make stiff and reliable wheel.

[Mark McM]

Well the guy made it work :D the wheel is actually ok in the stiffness dept?

It should be just as stiff as any other 24 spoke wheel with the same type of rim and spokes.

While people often obsess over spoke lacing pattern, lacing pattern has remarkably little effect on wheel performance. The things that matter are rim stiffness, flange offset(s), number of spokes, and spoke thickness. How you lace the rim to the hub has only a small affect.

[skiezo]

I have a rear 32 campy hub to 24 rim built by Dave at Speed Dream Wheels about 12+ years ago. Built on a sun venus rim and I put over 10k miles on that wheel set. Had the rims replaced once but I still have them and they are going strong.
Mine is 16 DS 8NDS.

[mhespenheide]

In '86, the tech-weeniest racer on our team had some TT wheels that used 48-spoke rims laced to 24-hole hubs. He claimed it was like drillium, but factory-approved.

:eek:

[muz]

When you have symetrically laced spokes with equal leading and trailing angles, all the torsions balance out, and you don't have a net torsion between flanges. But when the asymmetry and a mis-alignment between the flanges, it can actually break the the hub (particularly if it has a narrow spool between the flanges, like this wheel does.


Yes, but that's the beauty of this pattern. Note that there are groups of 3 spokes: one leading, one radial, one trailing. These spokes are all going to the same side of the rim. It's just that the groups are not equally spaced, or rather there is an extra hole between the groups of 3. So, there is no imbalance at all.

[muz]

In '86, the tech-weeniest racer on our team had some TT wheels that used 48-spoke rims laced to 24-hole hubs. He claimed it was like drillium, but factory-approved.

:eek:

That actually is a harder problem. The obvious way doesn't work well, unless the holes are in the center of the rim (not alternatingly offset on either side, as typical).

[oldpotatoe]

I think that pattern is called Crow’s Foot, but never seen it with skipped holes!

Crow's foot and some variations of that theme, some crossings, etc. I remember a Indurain TT bike(?) and also Olle Ritter's TT bike in Le Corse en tete, Stars and WaterCarriers, one of those?? Can't remember, had a crow's foot, 24h wheelset..the one where the wrench was cleaning out the Bianchi BB before the next days' TT..and Olle tucked his jersey in to be more 'aero'.

Lots of goofy lacings out there..
I'd be curious what the wheel builders on this forum have to say about skipping holes.
Obviously it's sub-optimal (at the very least, a 24 hole hub would have a stronger flange because it has fewer drillings), but I'm curious if a wheel builder would say "NEVER do this!" or "yuck, but it's fine".
Applying 24 spoke loads on a 32 hole flange seems like a great way to make a flange fail prematurely...


I'd worry about the drive side radial laced spokes..on that hub. Breaking a flange there.
While people often obsess over spoke lacing pattern, lacing pattern has remarkably little effect on wheel performance. The things that matter are rim stiffness, flange offset(s), number of spokes, and spoke thickness. How you lace the rim to the hub has only a small affect.

:banana::banana:

[Mark McM]

Yes, but that's the beauty of this pattern. Note that there are groups of 3 spokes: one leading, one radial, one trailing. These spokes are all going to the same side of the rim. It's just that the groups are not equally spaced, or rather there is an extra hole between the groups of 3. So, there is no imbalance at all.

I think you'd better look again. On a 32 hole hub, the holes on each flange are 22.5 degrees apart, and the holes on one flange are 11.25 degrees ahead of the holes on the other flange. By skipping a hole, each group of 3 spokes is 90 degrees apart, and each group of 3 spokess is 11.25 degrees ahead of the each group of 3 on the other flange. On a 24 hole rim, the holes 15 degrees apart. Since the spokes are laced to opposite sides of the rim, the distance between the right side spokes is 30 degrees, and the distance between the left side spokes is 30 degrees and the right side spokes is 15 degrees.

In order for the hub holes to align with the corresponding rim holes to be aligned on both sides of the wheel, the right/left hole offsets have to the same on both the hub and the rim. But in this case, they are not - the offset at the hub is 11.25 degrees, while the offset at the rim is 15 degrees. The 3.75 degree difference in offset means that the angles of the spokes on one side of the wheel will be skewed forward by 1.875 degrees, while the spokes on the other side of the wheel will will be skewed backward by 1.875 degrees, to make up for the differences in offset. Because the spokes one one side will be pulling more forward than the spokes on the other side, it will create a torque between the hub flanges.

The hub torque caused by the hub/rim misalignment will exist regardless of the lacing pattern, whether it be standard cross laced, crows foot, or radial. In the case of radial lacing, the spoke angles are low enough that hub torque will be quite small. But with crossed spokes, the hub torques will be much larger.

Interestingly, if you skipped every 4th hole on one flange (as this pattern does), but skip 2 holes in a row for every 8 holes in a row on the other flange, then can actually balance out the torques caused by the hub/rim hole misalignment.

[muz]

I think you'd better look again.

Yes, on further analysis, I can see how the wrong offset in the rim causes an imbalance, resulting in a twisting force on the hub barrel. Looks like a perfect excuse to use something like a Chub hub ;)