KBentley57

<rant>

So I was cleaning the bike this morning, when I noticed a crack around two of the nipples, about 120 degrees apart. I'm disappointed! I built these wheels with nipple washers, and used a tensiometer down to the single kgf to make sure I got it right. The roads around here can be rough, but I don't recall running over any ultra destructive surfaces lately. Just for reference, the wheel is built with 28h dura ace 9000 hubs, Salim laser spokes (2x both sides), alloy nipples, alloy washers. The drive side tension is 100 kgf, and the non drive side tension is about 55 kgf. Grease between nipple head and washer, anti-seize on nipple threads.

I'm going to see if Pacenti will warranty the rim, but honestly I don't have high hopes. The wheel itself has about 7000 miles.

</rant>

fietsbob

Build with a different rim .. that one may have been Over tensioned .

those things are not calibrated accurate to a Planet wide standard

[i never used a tension gage , & have wheels that are fine 30 years later ]

KBentley57

Added a picture since your post @fietsbob. It definitely fails the fingernail test too.

I should have added that in addition to the tensiometer, I also used a tone generator at the right frequency to double check. The max recommended tension is 125 kgf, so I'm 99% certain that I wasn't out of spec.

fietsbob

Maybe the spec was optimistic. My old road Bike : Rim, Mavic E2 from the late 70s (36_15 ga plain)

I just Squeeze spoke groups and pluck them ..

compare the feel with existing wheels that are already fine

Low tech don't work with High tech Equipment. you apparently do

Tension is a tone I hear not read a dial [Play guitar and mandolin.. 50 & 40 years]



maybe get a ferruled rim next time. E2 is double ferruled ..

HillRider

It's possible the rim's heat treatment wasn't right and the metal was left too brittle. Several years ago Trek had a run of their house brand "Matrix" rims that were defective that way and cracked at the nipple holes after a few thousand miles. A friend's late-90's Trek-made Klein had those rims and they died quite prematurely.

KBentley57

I'm just bummed is what I'm getting at.

Kopsis

Are these first or second gen SL23s? I know the first gen were prone to cracking like this, but the nipple bed is beefed up a bit in second gen to help prevent it. Please update when you hear something from Pacenti.

KBentley57

Looking at the differences in the bead blast finish, the wide vs narrower brake track, and the 622 x 20 vs 622 x 18.6 on the stickers, I've got the 1st generation. I've read a number of reports about the cracking, and the updated version is supposed to correct the issue. I'll be sure to update when I hear something later this week.

KBentley57

To update -

I got a hold of Kirk Pacenti, and he offered to make it good, so that's great news. Seems like a real upstanding guy from this interaction. I bought the rims with some other stuff from BHS, so I went there for the warranty. They're a little out of the '1 year', but he did offer me 40% off a set of HED Belgium +'s that I've been wanting to try out. I would have went with another set of SL23's (V2), but my craving for different things took over! Either way, good communication from both, problems resolved, will have pics of the DA 9000 hubs + HED Belgiums sometime next week.

ThermionicScott 

+1, Kirk is a good guy.

FBinNY 

To the OP,

Your particular build is of a type that I wouldn't expect to cause stress cracking at the spoke holes. But there are always other things possible. So to help me fill out the picture, is the cracking at a right side spoke hole or left? and, what do you weigh?

KBentley57

I weigh about 162. The cracks are spreading outwards in both directions on two drive side spokes. I suppose it looks like this " ----o----- " if that makes sense. it's not radiating parallel to the hub axle. Reading my post, I didn't make it very clear; it's the rear wheel.

dsaul

I had the same problem with an early Stans 340 on the rear wheel. It cracked at every drive side nipple with less than 1000 miles on the wheel. It was built to 110kgf on the drive side, the spoke bed was just too thin. The front wheel lasted for about 5000 miles before cracking at every nipple. Stans fixed the problem by making the next generation with a thicker spoke bed. I assume Kirk had a similar problem with the first gen. SL23 rims.