Crankycrank

My friend has a rear wheel with a 32hole Mavic A 719 rim and DT Double butted Competition 1.8-1.6-1.8 spokes.
2 of the eyelets have had the outer ring break off leaving the rest of the double eyelets intact and spokes are not losing any tension but I'm curious what would cause this? This rim only has about 5k miles on it.

Iride01 

Can't get a pic of the real thing with the broken eyelets?

Might be over tightened spokes. Might be other stuff too.

Not much mileage. Any warranty on it?

pdlamb

Just guessing, but did the builder lubricate the outside of the nipples? Aluminum nipples grabbing steel eyelets might break some, especially during a long wheel building and truing process.

Still guessing, might a couple spoke washers keep the wheel rolling?

Crankycrank

Thanks, ^^^ Might take awhile to get to the bike to take a photo but will post one up as soon as possible. The friend is reluctant to part with the bike for any amount of time so waiting to see if a warranty exchange is needed for this.

Crankycrank

I installed a new rim to replace one that was tensioned too high from another builder and started cracking at the spoke holes. I did use some light oil on the outside of the nipples to prevent grabbing and they are brass. I'm not a master wheelbuilder but have done maybe 15 rim exchanges and pretty sure the tension is correct. I doubt washers will be needed as this is just the outer part of the eyelets but the inners look pristine, no distortion or cracking.

Bike Gremlin

It could be poor quality of the rim. Not the first nor the only Mavic rim to do that.

Andrew R Stewart 

IIRC this rim model has what are known as single eyelets at the nipple holes. So only the spoke bed has this reinforcement. I have had a single eyelet come loose of the rim on one of the many (many) mavic rims I have used with no affect on the wheel's true, spoke tensions or reliability. The eye ultimately slid onto the spoke and acted like a spoke bead, rattling around until I cut it off with a pair of diagonal cutters. I forget what the inside looked like, it's been that long since it happened. Andy

FBinNY 

This is a par for the course settling or tolerance issue.

In order to do the intended job, the "cup" portion needs to be slightly short, so as to transfer load to the upper deck. Therefore, the maker intentionally sets the manufacturing tolerances to the short side, so case by case they vary from just a hair short to more short.

Rim extrusion varies (within a tolerance, or it's rejected) so things end up where sometimes the eyelet riveting cannot close completely. When built to tension, the spokes pull the cup down, taking the upper deck with it, until the load is balanced between both decks. That creates slack pushing the not fully clinched rivet forward.

FWIW - if you do not see some settling of double eyelets, it means that it just happens to be spot on (rare) or the maker toleranced in a way that the cup is not bearing on the upper deck, making it more about marketing than function.

Crankycrank

Here is a photo of the damaged eyelet with the broken ring hanging off the spoke. Photo looks dirtier than in the flesh. From all the comments it sounds like not an unheard of thing and not to worry about it too much. Mavic only warranties their complete wheels and not their rims sold separately.

FBinNY 

Yes, that's very different to what I had in mind. It's not a structural problem, since the nipple is supported from the other side, but still not an endorsement of the maker's QC.

BTW I see plenty of corrosion. Do you live near the shore?

Crankycrank

Yes and yes. Most of the corrosion at the eyelet is from the lip breaking off a while ago. I nag him about giving the bike a good fresh water bath every so often since he parks it next to the bay fairly often, but my advice is for nought. I considered the corrosion may have weakened the steel eyelets but I remember when he showed it to me when it happened there was no corrosion at the separation area.

Bike Gremlin

Are there any cracks (longitudinally - on the line from spoke hole to spoke hole)?
You might have to remove the rim tape and clean it well to spot them.

Relja The-Curious-Monkey Novović

FBinNY 

Salt water damage to rims is insidious. Salt water wicks under eyelets, or between the nipple and rim where the b drilled hole isn't anodized. After it wicks in the water eventually evaporates, leaving the salt. Each cycle adds more salt.

Once this starts, it's near impossible to.stop, so I've long ago started pretreating all my rims. I apply a wicking marine grade grease/rust preventative to eyelets, or use a Q-tip to alloy grease to each spoke hole.

This has served me and my clients well for decades, whereas friends dealt with rusted eyelets, or.stress cracked rims.

At this point, your wheel is beyond n saving, though there's an excellent chance it'll last until a crash solves the problem.

Just keep prevention in mind for the next wheel.

Crankycrank

I have taken a look at the condition of the inner rim and no corrosion on the inside and no longitudinal cracks on the rim although as mentioned this is a rim that replaced an identical rim that did have cracks from being over tensioned, but I did tension this one properly. We both live about a half mile from the ocean so corrosion is always a concern. I wash mine with soap and water every couple of months and don't have any corrosion issues and also have two set of Mavic Open Pro rims with basically the same double eyelets one pair being about 20yrs old. I will stress to the friend again that he needs to give his bike a bath every so often and maybe this will give him some inspiration. The thing is he has had several other sets of wheels with rims with eyelets and all are more than 5 yrs old, none of them Mavic's and with all the same riding and lack of cleaning conditions I've mentioned, and none have this issue.

GamblerGORD53

"Cracked because of over tension" <<< HOGWASH excuse.
They crack, corrode and break because the hole is twice as big and they are a STUPID ABOMINATION. The biggest SCAM in bike design.
I have Velocity Dyad rims on all my wheels. One has 30,000 miles with 2 heavyweight tours and then I rebuilt it a diff cross, looks like new with NO problems.
When I first built it I had the tension far to high, nothing happened.