Wheel building weirdness!
 

OK, so I took a class and built a set of wheels.

I've only completed the front one: campy centaur on Velocity Aeroheads, double butted spokes.

I did a really good job... The dish has an error of less than a millimeter, the wheel is round and true.

Every spoke on one side is 13 on the tensiometer. Perfect.

Every spoke on the other side is 14.

**********?

I don't even know how to correct this without screwing up my perfect dish. What did I do?

I know it's not a big thing, because it's still within spec, but it disturbs me, and I'd like to not do it again.


What happened? How do I fix it? The instructor said she didn't know, but would let it go if she were me.

This is normal for a rear wheel, and sounds just about perfect for an Aerohead OC. The drive-side bracing angle is shallower than the non-drive side, so DS is higher tension than the NDS.

But is it normal on a front wheel?

Did you prestress the spokes? It sounds like something may not be settled in yet.

Yes... I think so. I did the thing where you put the socket wrench in the V of the spokes and apply pressure... and many times throughout the process I used my hands to grab the spokes and squeeze.

And we checked the dish, flipped the wheel and checked it again, and it was really, really excellent.

And every spoke on each side was consistent. No oddball tensions.

i'm doing the rear wheel next, but I won't be able to tell if the problem is in something I'm doing, because the tensions will be off anyway.

How is the front laced? If it's radial, did you do heads out on both sides, or did you swap it on one side?

Its radial laced in threes, and I alternated heads out on both sides.

In other words, the spoke heads alternate between facing in and out on each side of the wheel.

36 hole?

Yes! A 36 hole front hub (and rim, too). I know... it's weird, but it was on steep discount.

what do u mean by "radial laced in threes"?

"This is normal for a rear wheel, and sounds just about perfect for an Aerohead OC. The drive-side bracing angle is shallower than the non-drive side, so DS is higher tension than the NDS."

Sounds like a good answer- if all the spokes had the same tension, it would also shift the rim over to be centered, right?

(A lower-tech wheel question- with a steel wheel with slight out-of-roundness at the weld, what do you do with it?)

I didn't know the name of it... Sheldon's site says it's called "cross 3".

StephenH, this was the front wheel, so I don't think it's supposed to do this....

I think I'm missing some basic concept. If one side were 10 and the other side 14, the dish would have* to be off, clearly....right? This is just a fact, with no weirdness possible, right?

If so, the dish should be off for 13 and 14 then, too.

So both the pulling and trailing spokes on each side are at the same tension? Is the wheel fully tensioned yet? If so to what? 13 and 14 are just numbers on a gauge. Which tensiometer are you using?

The dish may be ok (actually there's no dish to a front wheel but we get what you mean) but is the hub axle centered? What I mean is are the locknuts the same distance from the flanges on both sides? Has this hub been serviced? Or is it new? I'd look there if everything else checks out.

There is no such thing as a "perfect" wheelbuild. Your numbers are well within recommended specs (4% actual vs. 20% recommended).

Leave well-enough alone.

Bob

I would have guessed you had a washer difference on the axle, but you said you've flipped it around and it's still centered, so that's not it.

You didn't by some chance build the rear OC rim into a front wheel?

Thanks guys.

No, I don't have OC rims. They're regular Aeroheads.

I was using the equipment at the bike coop where the class was. I think I won't worry about it until my truing stand and tensiometer show up. I can't answer some of these questions because the class is over now.

I know it's within specs, but it's just irritating that each spoke on each side is so consistent. I suppose it could be some oddness in the rim itself, or the hub, which is new.

The term "radial" refers to wheels where no spokes cross each other.

I'm sure there's some explanation for why the tension isn't exactly the same on both sides, but darned if I know what it is. Washers/spacers on the wheel placed asymmetrically, or an off center rim, would explain the problem, but you may have to accept that nothing is perfect and that you have built an awfully good wheel. (but be aware that it's unlikely the spoke tension/trueness will be as even as it is after the first 100 miles of riding.)

Well, if it happens again, I'll worry and bother you guys again.

It's so cool to have done this. I really, really enjoyed it.

Post a photo of the wheel, at about a 30-degree angle.

One thought I have is that one side's spokes may not have an "interference" crossing , so the spokes aren't touching.

Also, I would recommend you download Park's TCC spreadsheet, fill it out, and look at the radar graphs. It's an EASY way to see what a wheel's doing.

Post some screenshots of the graphs too. It's possible that you're not seeing what you think you're seeing.

OK. I will do both once I get my truing stand and tensiometer. I only ordered it a few days ago, so I'll reopen this thread in a week.

I've never had a front wheel yet where every spoke was exactly identically tensioned.

I use this graph and love it. It's especially helpfull to get a visual representation.

Yeah, but we're talking about a variance between the left and right sides, not all the spokes in general.

I'm gonna have to come to your house to do my wheel touch-ups now!

It sounds like you did very well, even with the difference in sides. Elsewhere I suggested you need a wheel alignment guage (dishing guage), but if you have a new Park stand coming that should be accurate.

I already have a dishing tool.. I picked that up at a garage sale last summer. All I'm missing that I need to order are a few books and a nipple driver.