How-To/Mechanics: Relacing used hubs to new rims -- spoke orientation

So, I've got some very nice Campy Nuovo Record hubs that I want to lace to new Sun CR18 rims. Looking at the Brandt book I find that he recommends that the rear hub be laced so that pulling spokes exit on each side from between the flanges -- that is, mirror image lacing with the spoke heads on the outside of the flanges. The rear NR hub that I'm going to use, based on the marks on the flanges, was not previously built that way. Looks like the right side pulling spoke was on the outside of the right flange (spoke head inside) and the left side had the pulling spoke inside the flange. Looked at some other wheels and found everything different. A set of wheels that I built a number of years ago match Brandt's recommendation (no surprise as I used his book). A rear wheel that I bought several years ago from Performance has a Mavic T520 laced to a Shimano 105 hub in the same manner. A Mavic rim laced to a Campy Record hub that I bought from Colorado Cyclist back in 1997 has mirror image spoking but with the pulling spokes exiting the outsides of the flanges. An Ambrosia rim laced to a Campy hub (probably Veloce) that came on a Bianchi back in about 1986 is laced in the manner that the used NR hub was -- non-mirror, drive side pulling spoke exiting the outside of the flange.

So, the question is, is it important to lace the spokes in the used hub the same way that they had previously been laced (which, I understand is the preferred way to do it) or is it better to lace in the manner that Brandt recommends even though some of the new spokes will then cut new indentations into the hub? Or, is my understanding about used hubs wrong and is it better to lace used hubs so that the spoke elbows encounter 'virgin' aluminum?

There are more experienced hands on this site than mine, but personally I wouldn't worry about it -- lace the wheel the way you'd like. I've rebuilt a ton of used hubs, sometimes in the same pattern, sometimes not, and have never had an issue. Heck, I've reused spokes, swapped spokes DS to NDS and back to get the lengths right, exchanged rims, etc. Logic dictates that putting a spoke in a new position for an old hub (assuming it's in good shape) is the same as putting one in a new hub; the spoke will seat as required and all will be well.

On the whole mirror/not-mirror/inside/outside question, my personal preference is to have the pulling spokes exit on the outside of the flange, DS and NDS, the theory being that the wheel will have ever-so-slightly greater width (less dish) in the situation when it's under the greatest stress.

One note: While I mix and match pretty much everything (again, assuming it's all in good condition), I stick to high-strength builds -- 3x, 32 spokes front, 36 rear. That way if you lose a spoke on a descent or whatever, the worst that happens is that the wheel goes out of true. Swap out the bum spoke and you're back on the road.

Both the front hub and the rear hub are 36 spokes and I'm going to do 3X on each with new DT spokes. The Sun rims are new as well.

I acquired these hubs several years ago and just now am getting around to actually building the wheels which are destined for use on a Bob Jackson touring frame that I'm going to ride in the ride across Iowa this summer.

I'm not sure if I remember correctly or where I read it, but I seem to remember reading somewhere that it's best to not change the orientation of spokes when rebuilding with a used hub. The idea being that the distortion caused in the softer aluminum by the SS spoke represents localized damage/work hardening and it's best not to create more by changing the spoke orientation. Putting a new spoke in the same way won't further damage the hub as the aluminum has hardened to match the SS. Makes sense on the face of it, but I'm not a sufficient expert in the science to say for sure or whether we're talking about something significant or just a theoretical mole hill.

As for how pulling spokes should be oriented, Brandt claims that having the pulling spokes leave the flange from the outside on the right can cause the derailleur to hit the spokes when under high load in low gear. Also, he says mirror image in order to reduce distortion under load. I'm not sure I understand his argument sufficiently, but he is a mechanical engineer with a lot of experience in the theory. I understand that by having the pulling spokes leave the outside of the flange on the right and the inside on the left that there is a little bit of dish reduction with the pulling spokes.

In all probability you guys are right and I can just build in any consistent manner and everything will be fine. These wheels aren't going to be grossly abused. Although I'm a tad over 200 lbs, I'm not that hard of a rider so decently built wheels will, no doubt, suit me fine. I shouldn't obsess.

Thanks for the comments you folks have offered. It's helpful to get thoughtful opinions -- very helpful.

Posted By: desconhecidoBoth the front hub and the rear hub are 36 spokes and I'm going to do 3X on each with new DT spokes. The Sun rims are new as well.

You'll be totally fine.

Posted By: desconhecidoThe idea being that the distortion caused in the softer aluminum by the SS spoke represents localized damage/work hardening and it's best not to create more by changing the spoke orientation. Putting a new spoke in the same way won't further damage the hub as the aluminum has hardened to match the SS.

Maybe, but that seems to be way overthinking it. The only thing I'd hesitate on rebuilding is a hub that had been set up with radial lacing. Much higher stress, plus it goes in the direction of the flange with the least thickness on it.

Posted By: desconhecidoBrandt claims that having the pulling spokes leave the flange from the outside on the right can cause the derailleur to hit the spokes when under high load in low gear.

Too many variables to be able to make any claims of this nature. Campy or Shimano? How many speeds? How close is the lowest cog to the spokes? Any spacers? Is the derailleur properly adjusted and its cage true? How about the derailleur hanger? The width of a spoke might make a difference in a few odd cases, but I'd argue that it's far more important to have a stronger wheel than to choose a slightly weaker one because it might save you a nicked spoke.

Let us know how they work out.

Dammit. I had a recommendation: make sure the inside of the flange is filed smooth. Otherwise, the indentations' walls are raised and cause a stress riser right at the J bend. I don't KNOW that it causes a problem, but it makes sense, and others have pointed it out as an issue - maybe even Mr. Brandt hisself.