Wheel Lacing Question
 

I volunteered to help a friend rebuild his rear wheel (he unlaced it thinking he would do it himself, then wasn't able to re-lace it), and I have to decide something about the spoke lacing. The wheel is standard hipster issue; an IRO flipflop (fixed/fixed) hub, straight gauge spokes and velocity deep v rim.

I know that traditionally, "pull" spokes are laced to the inside of the hub, and yes I understand this is a holdover from dished wheels in which one wanted the pull spokes to "pull in" when under tension, to avoid hitting the derailleur, and that this is not an issue for a fixed gear. I also know that wheels are laced symetrically with drive-side and non-drive-side pull spokes both on the inside, but I was thinking of doing something different.

So yes this is more a stylistic question. I was thinking about lacing the wheel asymetrically, so that either way it is flipped, the drive side pull spokes are always on the inside (and consequently the non-drive-side pull spokes will be on the outside). I have heard that asymetric lacing is a hallmark of cheaper, mass-produced wheels...is this true?

Should I do it, or lace it symetrically?

Years ago Mavic built up a group of wheels with all of the lacing paterns of conventional wheels. The least amount of spoke breakage came from wheels that were laced mirror image with the pulling spokes on the outside (spoke heads on the inside of the flange).

Wild! I wonder why in the heck that would be.

I'd like to see the paper that Mavic published from that. All I've read, and I've read a lot, is that it doesn't matter.

See http://www.sheldonbrown.com/wheelbuild.html and scroll to the section marked "Which Side of the Flange?"

Lennard Zinn also teaches this (IIRC) in his Zinn and the art of Road bike Maintenance book. Apparently the hub flange helps to provide support for the elbow (weakest part of the spoke) and helps to avoid breakage. I've read that lacing the pulling spokes on the outside is the standard in Europe, and here in the US we've (generally speaking) taken advice from Jobst and Sheldon and created the opposite "standard."

Roger Musson also primarily teaches the pulling/outside pattern. It's these two books that I own, so I've always ignored the Sheldon/Jobst approach and built them as the Mavic study (apparently) suggests.

The point that Roger makes is that spoke clearance under torque used to be a bigger issue due to dérailleur design and oppositely on the front with disk brakes (under hard braking) but isn't usually an issue with today's components. Wheels can be built well both ways i think, so I wouldn't worry too much about it.

I just built up a set of wheels and laced them pulling/out but in order to align my hub labels the same way front and back, I had to lace the front wheel as a "type 1 rim" and the rear wheel as a "type 2 rim" which was possible because they are center drilled. Nobody is likely to ever notice the difference. Perhaps White Industries believes that the front hub label should be readable from "facing" the bike, rather than sitting on the bike. Had I built it that way, I'd have used the same (type 1) on both with matching orientation.

Wheels are fun because when it comes down to it, you can lace it however you want if you balance and tension the spokes properly.

-Jeremy

-Jeremy

there will be notches in the hub from the tension of the spokes, so it's best to reuse those notches instead of making new ones by changing the lacing pattern.

You can distinguish the spokes on the outside because they will have their heads bent in more than the spokes on the inside.

I've always been a believer that the highest loaded spokes should come off the outside of the flange. It has the drawback of the point of cross moving out under torque load, but I've never had that become an issue. My theory as to why this is the stronger arrangement, is that on most hubs the outside spoke touches the flange lip on the way out. That limits the flexing at the elbow somewhat, moving the flex zone out to the straight section where it touches the flange, thereby reducing fatigue at the weaker elbow. As I say, it's only my theory, but it's served me and those riding my wheels well.

As to mirror vs non-mirror lacing, I don't think there's a qualitative basis, either way, and it reflects the building system more than anything else. Most folks lace by habit, finding that ingrained patterns save think time and are therefore faster and less prone to error.

Handbuilders building 1 wheel at a time usually flip the wheel over when lacing the second flange so the wheel naturally comes out mirrored.

In a production setting all the spokes are preloaded into the hub and then laced on a machine where the spoke is brought out to the rim and a nipple automatically spun on. Spokes aren't laced is sets of four but both crossing spokes are laced together in sequence then the next pair. It's easier to train your fingers to cross the right over the left (or the other way) then to try to learn to switch the cross. When paid on piecework, where lacing takes 30-45 seconds per wheel, flipping the wheel half way is also too time consuming, so the builders lace the lower flange first, then the upper in the same pattern, producing non-mirrored wheels. This probably raises productivity by about 10% or so.

As I said I'm not sure it makes a difference either way, but is a clue to whether it's a production or one up wheel.

That's what I think too but my logic comes at it from a different angle.

Here we have several people, whose qualifications I don't question, who have strongly held but opposing opinions. If any of these folks were experiencing repeated failures don't you think they would change? Since they don't, I assume that either pattern, assuming it's well done, will produce trouble-free wheels.

A couple of months ago we had a looooong thread about spoke prep. Lots of people, who sound proficient, have strongly held but contrary opinions. My conclusion at that time was the same - it must not matter very much because, if it did, some of those folks would experience wheel failures and change their opinion.

as long as the spoke count and pattern is sensible for the weight and the spoke tension is balanced, it would seem that nothing else really matters.

I've said it before in the past...but I'll go ahead and say it again...

Outside pulling is a "tad" more reliable...

Inside pulling is a "tad" more responsive...

....now about that "tad"?

It is so miniscule that maybe, just maybe, someone like Lance or Greg (pick one) might notice the difference...the key word being "might".

Bottom line is - if you are going to get freakingly hung up on such a detail then I can only ask the following with a sarcastic tone:

1. Why do you have a bike?
2. Going somewhere?
3. Do you even ride?
4. Hell...do you know how?

=8-)

Right, but there isn't a lot of data available about wheels once they go out the door. If you're a regular bike shop mechanic, you get a little data, but you don't know exactly how your customers ride, and none of it happens in a controlled situation. I might believe Mavic's thesis if I saw it and if their methods seem sound.

This is why the folklore abounds. Even the experts are in the dark, to a degree.

Jobst Brandt is one of the few who measured the forces going on.

I have a front wheel that is built with a King "Disc-Go-Tech" hub (now called the "Universal Disc" hub) that takes various adapters for different types of discs, and the flange width, dish, and ISO disc mounting surface are such that there is very little clearance between the BB7 I'm using up front and the spokes. The wheel is built just like a rear wheel with "pull" (if there was any "pull") spokes inside, which under braking of course produces the opposite affect of a rear wheel and pulls the spokes outward. With the tolerances as they are this is absolutely an issue and I have heard under very hard braking the dreaded "pling pling" of the spokes on the brake body. This wheel is going to be rebuilt with a different hub and with lacing such that braking pulls the spokes in.

Haha, awesome :-)

I don't have any disc brake wheels, but I have road wheels that are built with pulling spokes facing back, facing forward or different on each side. The difference is imperceptible to me. Pedaling doesn't apply enough torque to distort the wheel much, especially if you don't use real low gears. The only time I hear the derailer hit the spokes is when I stand when climbing. I'm pretty sure that is caused by side loads from rocking the bike, not my awesome strength.
The biggest change in spoke tension is the reduction in tension that occurs when the spoke rolls through the bottom of the wheel. When that happens the spokes may move a little towards the spoke that is on the outside of the cross, the movement should be less than have the diameter of the spoke. It doesn't matter how you lace the wheel, half the spokes will move in a little, the other half move out, if they move at all.
OTOH a front brake is more powerful than any rider, so maybe that might distort the wheel a little, or maybe even load it up enough to start it going into a potato chip shape.

em

I'm sure eddy m is right. Pedaling torque is less significant than weight, and braking is bigger than either of those.

I believe lacing with the pulling spokes on the inside is easiest. But do whatever is easiest unless you are building a disk brake front wheel.

A point that I've pondered for years. I know about the wheels that I've built for my sons and for personal use, maybe for a few other close friends. I sometimes wonder about the wheels, especially some of the unusual wheels, that I've built for people who I seldom see.

If you haven't read The Bicycle Wheel, by Jobst Brandt, I suggest you do. I read the first edition which came out in about 1983. At the time, wheels normally had 36 spokes on pretty much all kinds of bikes except small-wheeled bikes. So the normal choices were 3-cross and 4-cross. He said that there is no functional difference between those patterns. He said there is no advantage to funny spoking patterns, either, and he spoke strongly against radial spoking for all applications. He also said that large and small flange hubs are functionally identical.

The book is in its third edition, and I don't know how it has changed. It is probably comprehensive enough to cover modern wheels, and I understand he made some technical corrections.

Sheldon advocates the use of radial spokes on the non-drive-side of the rear wheel, something I find interesting and am toying around with for my next build. But I would like to hear what others have to say about this.

Sheldon was the guru of all things biking, including the arcane and archaic, but I think for wheelbuilding it's a slightly different matter.

Likely given the prevalence of 36 hole hubs which would need quite large flanges to leave enough material between spoke holes for radial lacing. I've seen a few hubs where radial lacing is only recommended when using the lower spoke count versions (generally 28 or fewer spokes).

I'll preface this by saying that I don't build wheels for a living and haven't built very many wheelsets. But in my opinion, you'd be better off using an offset rim to equalize tension rather than running only 8 non-drive side radial spokes. It's going to be lighter wheel spoked that way but it won't be very easy to true and a spoke failure on the non-drive side would be a real problem. And unless you don't mind seeing unused holes on the hub and rim, you'll need to search out hubs and rims specifically designed for that style of lacing, and there aren't very many of them.

The rear wheel I built for my commuter using an offset rim had nearly 80% of drive side tension on the non-drive side. Coupled with thinner butted spokes on the non-drive side, I don't think I'll be seeing any fatigue issues there any time soon.

Yeah, the radial non-drive side radial spokes is to compensate for the large amount of dish present in modern wheels. It's fixing a symptom, but not solving the actual problem of too much dish. So much dish that on A LOT of wheels, you see non-drive side spokes at 50-60% of full tension just to centre the rim between the locknuts.

If you are going to build a wheel from scratch anyway, you're not limited by whatever rim & hub the bike-manufacturer gave you. Offset-drilled rims and hi-lo flange hubs really let you equalize the included-spoke angle where they meet the rim for very even spoke-tension and maximum strength & durability.

Also on most hubs, there's a 2-3mm axle-washer on the drive-side that you can move to the opposite side to reduce dish. I've milled down freewheel & freehub bodies to move the cog stack closer to the spokes as well. Shimano did this on their 10-spd cog-carriers for the larger gears, giving the impression that a 10-spd cassette is narrower than a 9-spd one. Not really, the 10-spd cassette just sits closer to the spokes and creates a gap under the lock-ring. Again, freeing up space on the right side to move that 2-3 axle-washer to the left to reduce dish.

On that flip-flop hub, I would pick a lacing pattern that puts the pulling spokes equidistant from the centre between the lock-nuts. So in one orientation, if the flanges aren't perfectly on-centre for zero-dish, I would put the pulling spokes on the side closer to the centreline. If the flanges are to the left of centre, I would put both pulling spokes on the right of both flanges (outside of if left-flange and inside of right-flange).

Flange diameters weren't that different between then and now, about 38.5mm PCD for a rear hub flange regardless of drilling. It's just that some hubs have larger-diameter flanges with same PCD, giving more material on the outside of the spoke-holes. This is much more common nowadays to find radial-lacing safe hubs than back when Jobst first printed his book.

Sheldon's idea was that pedaling torque caused the non-drive side leading spokes to go slack, leading to early fatique failure. Radial spokes don't transmit torque, so they won't go slack from pedaling forces.
I never bought that idea. I think it's far more likely that that static weight load causes the spokes to go slack, and radial spoking doesn't address that at all.
I think what's really going on is that non-drive side spokes sometimes don't have enough tension to seat properly, and that allows a little flexing of the elbow every time the spoke rolls through the bottom. Using double butted spokes and seating them carefully should be enough to insure a reliable wheel, if the wheel is tensioned adequately.
I like to use one gauge lighter spokes on the non-drive side, but triplet lacing should be stronger than a symetrical wheel with the same number spokes, and lighter than an offset rim. Those are all reasonable ways to build a rear wheel. of those choices, triplet should be the lightest, offset rim strongest or most reliable and lighter non-drive side spokes the easiest way to correct a problem wheel.

em

Check out the photo gallery of Sheldon's personal bikes. I'm thinking he wasn't totally sold on the concept.

I broke a non-drive side spoke on Saturday. It surprised me, though I gather it isn't unheard of.

I build wheels with the pulling spokes on the inside, in a 3x pattern. Under load, the pulling spokes will see more tension than the trailing spoke, resulting in a net force toward the rim's center line.