I'm far from expert on this, but I do ride wheels I built myself from Fiamme Ergals, 28 holes front and rear, and I've had zero problems with them. I weigh 150 pounds all year long. A few questions and observations:
You don't mention the spoke thickness. I took the opportunity to mention my choices to Jobst Brandt, who said they sounded "about right" - I used 15/16/15 spokes. One could argue that lots of thin, flexible spokes are the best solution in general - with only 28 spokes, 15/16/15 still seemed like the right choice for these lightweight rims.
I've also used these spokes with 28- and 32-hole Mavic GEL280's, a slightly heavier rim (mine are all around 295 grams) with the same very good success - no problems at all. I think a better wheelbuilder than me might choose 14/17 or 15/17 spokes but, having worked with DT's Revolution spokes (in one of those sizes, I forget which), I decided they were more trouble than they were worth for me, while 15/16/15 spokes were fairly easy for me to build up into a good wheel that would hold its true.
So what spoke guage were the wheels you had problems with?
From the sound of your problem, it may have been that the combination of heavier spokes and too much tension was more than your rim could bear. That's just a guess, and I'm looking forward to hearing what spoke guage you had and any indication as to how tightly it was laced.
-S-
Rick Verhoeven wrote:
>
> I kept meaning to bring this up during the "28 hole hub" tread that went
> along last month, but I missed it.
>
> I experienced my first broken rim a couple of months ago. Having heard many
> raves about the ride quality, I acquired a set of 36 hole NOS Fiamme Ergal
> rims to use on my "new" '71 Masi. I had them built by a well known wheel
> builder who has much experience with vintage wheels including Ergals. After
> about 200 (easy but wonderful) miles, I noticed a very small crack along the
> top edge of the side of the rear wheel. Over the course of the next few
> days, I watched the wheel gradually pretzel itself. Even after I completely
> loosened the tension of all the spokes, the wheel continued down it's
> self-destructive path eventually popping a 1.5 inch piece of rim sidewall
> completely off the rim!
>
> I was well aware of the liability riding the Ergals (especially at my winter
> weight of 185 lbs.) before I ever purchased them. I have been in touch with
> the builder, and he graciously offered to re-build the wheel for me if I
> supply the rim. I do have one more NOS Ergal, as well as, a cosmetically
> matching NOS Fiamme Red label. Should I even consider using the new Ergal
> or just be safe and use the Red?
>
> In addition, though my weight stays in the 180's I've never had wheel
> problems at all including many, many hard miles on a set of Mavic GL 330's
> (36 hole). Also, I know that I didn't hit anything hard during the 200
> miles I used the wheels. Any thoughts? Opinions?