Crows foot lacing
 

I'm planning on lacing a modified crows foot on a 32h hub/rim. The Idea is four sets of feet separated by a set of radial spokes, to achieve the multiple of six I need to do crows feet. My question is about spoke tension. Since half of my spokes will be radial and the other half laced 2X, should the radial spokes be laced with more tension like you'd normally do when lacing a radial wheel? Or should they all have the same tension? This is a front wheel, 105 to a Deep V if that's important to you. I have a Wheelsmith tensiometer, so I will be able to do this accurately.

Thanks for any tips.

Petr

Can't find my tensionometer, so I checked Jobst Brandts book. Not much mention of the Crows Foot pattern, but seems that equal tension on all spokes is optimum.

That's also what I recall when I replaced the front wheel on my Colnago.
It's laced Crows Foot with 36 spokes. I'll be interested to see your "modified" pattern, as Jobst says only multiples of 6 can be used, 24, 36 & 48.

I'll post a pic tomorrow when it's done, but I only have a cell phone camera.

I tried drawing a pic to put up with my original post but it wasn't coming out well. Actually found a drawing just now so here's a taste.

http://www.geocities.com/spokeanwhee...s_foot_f32.gif

This is the site where I got the idea originally a few months back

I'd think that the trueing process would determine what the relative tension of each angle of spoke would have to be.

Just curious. Why would you use more tension on a radial spoke than on a non-radial one?

That's a good question. I'm thinking since the spoke triangle will be shorter that would affect tension, certainly on a crow's foot that has different spoke angles.

Maybe one of the engineering guys will weigh in and tell us more about angles and spoke tensions than we want to know.

Sorry if I'm hijacking, but Is there more than a visual advantage to this lacing pattern? What is the theory behind it? IMWTK. Thanks.

-soma5

The idea is that half your spokes are radial (lateral stiffness) and the other half are essentially 2 cross for torsional stiffness. Plus I'm hoping this is less likely to rip off a section of flange if I experience spoke failure like a standard radial lacing is said to possibly do.

The final tension on the spokes should actually be identical. That's because the tension at the spoke-nipple should be the same as if the wheel was laced up 2x or 3x. The rim can't tell what kind of pattern you have, just the tension from the individual spokes.

I actually use a different pattern than that one. Personally I think crows-foot should be used only with spoke-patterns in multiples of 6. If you remove the middle spoke in between the crossed ones, it'll look A LOT cleaner. You'll end up with a 24-spoke wheel.


Here's a picture of my 18-spoke wheel from my track bike (notice the thicker hub-flange for radial-lacing):

http://i42.photobucket.com/albums/e3...rowsfoot3s.jpg

Ah, interesting. Sort of a compromise, get a little of each. I've never seen that before. Thanks.

-soma5

Here's a link to a thread which you might find interesting (with links to similar threads)…

- Wil

I hope it is just to be used as wall art. I wouldn't plan on any fast descents on that wheel. If you do buy a good life insurance policy and make a loved one a beneficiary.
Looking at drawing the spokes are all "outbound" and the spokes aren't really 2x but are merely passing each other on the same side of the hub. A true cross involves 2 spokes crossing from each side of the hub one inbound and one outbound spoke which gives some mechanical advantage. Good luck.

By the end of the first sentence I was all... :roflmao:

Then I got to the "all outbound" detail...so I checked my 'Nago and the 2x are outbound, but the radials are INbound. (and 36 spokes)

That wheel was built about 20 years ago and I've been brutal to it over all those years! :eek:
Still hasn't needed retrueing. It's just as straight as the day I built it.

And it's just MHO, but if you build all radial, aren't the spokes generally all outbound? The ones I've seen are. So why would that make any significant difference in lacing Crows Foot all outbound too?

I mean, I've made some hairball descents on my Crows Foot wheel and as mentioned above, it's still perfect.

As a derail here, I used to work in a shop and one of the mechs was a pro at building wheels with spokes that are actually TWISTED TOGETHER! :eek:
Makes kind of a flower petal look to the spoke pattern. He also figured how much longer each spoke needed to be per twist. I think his standard was 3 twists. Wish I could find a picture.

He also brutalized those wheels and nary a problem. A bicycle wheel is a phenominal piece of structural engineering!

I noticed the all outbound drawing too and because every other in my modified design is radial, I decided to make all the radials outbound the the crossed spokes inbound. Still lacing as the wife demanded some time last night.

Here's a pic of twisted lacing, but I think I've seen other versions too. Head mechanic at the shop I sometimes work at says twisted spoke lacing is nearly indestructable (if done right of course.)

http://www.instructables.com/files/d...VTC.MEDIUM.jpg

As I understand it, the mechanical advantage of spokes crossing (besides this being the only way to intersect with the hub at the correct angle for torsional stiffness) is when you zig zag the spoke through the last crossing you add lateral stiffness. My 16 radial spokes should account for that.

In terms of in/out, in/in I think that is more about avoiding sharp angles when spokes pass near the hub. I've never heard anyone talk about making sure the inbound is zig zagging through the lacing in a particular way rather than the outbound.

If I die, I'll make sure to post some pics. :D

thats interesting. The one that I built, I found that the twisted spokes act as a spring, making the wheel totally unridable. I was bored one night, and had a bunch of long spokes kicking around, so i built this:
http://i69.photobucket.com/albums/i4...6/101_0215.jpg

it looks cool, but it would fold like a taco if it were ever mounted up. However, after looking at your picture, maybe I will take it apart, and try the pattern that is in your picture.

I guess it is my size that makes me skeptical 210lbs. I have seen the twisted spoke wheel at a shop up in Ft Collins, CO. There it was wall art. I never talked to anyone who has ridden one. My hat's off to you. Please send some photos when you get the bike wheel built.
I don't know if it is an optical illusion but the spokes in the twisted lacing look pretty thick. Are they? And are they Stainless or are they chrome plated steel? Stainless doesn't take to bending without weakening. Always willing to learn something new. I started riding before SS spokes were a good product. Chrome plated steel were reasonably good but, in racing on the track I always tied and soldered the 3 and 4X lacings with steel wire and soldered them. That was the only way I could keep a set of wheels from popping a spoke every other Sprint. Early SS were terrible. Today the SS spokes are fantastic. I have one set of wheels I built with over 20K miles and not one broken spoke. Conventional 3x lacing, record hubs, and Open Pro rim. Good luck and I wasn't wishing harm to anyone.

Finally done. Now it's a test of time. Sorry for the crappy camera phone pics.

Lacing the crossing inbound and radial oubound left a ~2mm gap between the radial and crossed spokes
http://i120.photobucket.com/albums/o...0208_23381.jpg
http://i120.photobucket.com/albums/o...0208_23421.jpg

If I remember right, one of the father's of mountain biking showed up at a XC race with a pair of twist spoke wheels.

they were all the rage in the early 90's

But my wheel = wall art.

http://www.cyclemonkey.com/gallery.shtml

That site shows a few different patterns that are laced with very nice components. I feel as though if you use proper spoke length after a little bit of plug and play, and a decent hub and rim, the wheels will be worthy of even downhill use.

I'm building a few twisted wheels up soon for a local bicycle sharing program we have here in the city of Buffalo. They will be wall art, however I think that when I have enough practice doing them I am going to build up some wheels for personal use.

I'm actually in the middle of building a rear flip flop fg/ss wheel that is a 2 leading 2 trailing design. I'm doing it with 40 spokes! you have no idea how hard it is to find a 40 hole flip flop rear hub. But i found one on the bay its an old FB. (pre campy)

Why not? Lateral rigidity will be up a little due to the radial, heads-in spokes, and if he's using rim brakes there's no torque transfer from hub to worry about.

Marginal mechanical advantage, if any. The only advantage of the inner/outer cross I've ever noticed is that it prevents vibration noise if spoke tension isn't up to spec.

Depends. If you want every scrap of lateral rigidity the wheel can deliver, then heads-in will give a slightly better bracing angle. It'll act pretty much as if the hub flanges were one flange with wider apart and higher, which is good for lateral rigidity.
But then there's an ever-so-slight aero advantage claimed for lacing heads-out. Supposedly the wind "inside" the wheel already is so turbulent that a few spoke elbows going round and round isn't going to make any difference. Apparently there's still a bit of laminar flow to be found on the outside of the hub flange, which will be less disturbed by the spoke heads than the elbows.

Let's not forget aestethics either. If you have differently coloured spokes and hubs lacing heads-out will give you a nice dotted pattern. (and the chance to show the world what' stamped on your spoke heads...)

I've seen someone stating that 4 mm/twist was a ballpark value for spoke length calc when doing twisted spoke wheel builds.

As far as looks, I like the pinecone pattern better than crow's foot.