repairing a pulled-thru spoke? - was mavic cosmic repair
 

okay.. so the spoke has seemed to pull thru the rim..

Is there an effecient/light weight way to repair this without the wheel going too much out of balance?

other than welding more material; could I use JB weld + washers on the spoke nipple?

blood & tears?

Why not just replace the spoke and the nipple? You will have a stronger wheel than any mickey mouse repaired wheel. You don't want to jerry rig a wheel, especially if it is low spoke count. If you pop that spoke while riding it could cause others to brake and destroy the wheel or cause an accident. Just my opinion.

depending on the alloy it could be weldable....but search on the fun with R-Sys Mavic wheels....maybe you could have the same fun with a patched up rim that breaks in half at the weld

Replace the rim. If a spoke nipple pulls through it, it's done. There is no safe or effective way to repair it.

Good grief - replace the flippin' rim!

ok, if I have a rim with broken eyelets, I'll need replacements.

from what I can describe, it looks like these:

http://www.lickbike.com/lickimages/2035.gif

the "U" shape part in the center. I desperately need 16 of these :D

or the sunken part, here:

http://i173.photobucket.com/albums/w...y/100_6028.jpg

http://www.lickbike.com/lickimages/2118.gif

=================

UPDATE:

yes yes, i know, replace the rim, but I am on a budget and practicing a new cost-containment strategy so that we (wife) can consolidate only necessary expenses in which expenses that are not critical to our success (marriage) can be pushed back to next fiscal quarter (whenever I have more cash for cycling)

OK,

well, if anyone is interested, i'm going to continue updating this thread for reference purposes.

The OPEN PRO eyelets should work, however they are only 3/5ths as deep as the original DOUBLE eyelets in the cosmics. If the eyelet in the cosmic cracks, which usually is the case, the rim only relies on the INSIDE eyelet for its tension - and thats a lot of tension for a 16 spoke wheel.

hence, getting an OPEN PRO eyelet will only work in conjunction with a longer spoke. 310mm will work lengthwise as it pairs right up to the rim-bed for tubulars. This can be trimmed and even re-tapped by a skilled wheel-smith.

Now, the question is that the open pro eyelet will be unsupported on the inside of the rim. this will ONLY leave the eyelet supported by the cup, and inside the rim bed. a ridged washer or coupling could improve this by making contact with the inside of the rim, although I am hoping that a single eyelet, being pulled with slightly more leverage now coming from the outside and not inside of the rim, should help alleviate the stresses from the tension.

I didn't read all that but "eyelets" are not replaceable. They don't crack either. Rims crack and the only cure is a new one.

You're not pulling our leg here are ya?

I'm afraid what you need is a new wheel.

Al

yes.. i know.. just wondering tho, do you remember if on your pair of cosmics carbones if the eyelet design + rim alone is identical on the front/rear? since they are 16 spokes front/rear.

mike, i am half trying to repair a wheel that otherwise is a boat anchor........... and la bicicletta has taken this on.. dunno if this is going to be an exercise in patience, or will this slowly blow up on me on the donut ride........

damn craigslist!

http://lh3.ggpht.com/_cQqeYvj8iq0/Sj...6/IMG_0602.JPG

I believe the eyelets are the same if front and rear are 16 spokes.

A Cosmic and a Cosmic Carbone are very different. Which do you have?

cosmic carbone, the front/rear 16 spoke version.

interesting tho.. maybe i could relace the rear and get a new front wheel...

but i think the inherent weak rear should just be getting a new rear... oh well...

just an update after some riding..

the open pro eyelet worked, after obtaining a 310 mm spoke. all is well, round and evenly tensioned.

one thing to note is that the old eyelets were aluminum, which I believe are too brittle and the newer open pro eyelets are brass.


NEW:

http://img43.imageshack.us/img43/1745/img0610n.jpg
Shot with Canon EOS DIGITAL REBEL XT at 2009-07-03

old

http://img219.imageshack.us/img219/5797/img0611y.jpg
Shot with Canon EOS DIGITAL REBEL XT at 2009-07-03





as you can see, the old eyelets are a touch smaller, and significantly deeper.

??? I don't see any way an Open Pro eyelet could work with a Cosmic Carbone. I have both.

I couldn't get the images to work on this latest posting.

When my Cosmic Carbone eyelet broke I was able to tighten the spike on the broken eyelet and true the wheel. This worked for about 10 miles.

Good Luck

Is there enough room to pull out an eyelet and spoke without damaging a rim? And if you put in a new one aren't you just forcing the upper wall of the rim to take the load, since the whole point of an eyelet is to spread the load onto both the top and bottom walls of the rim? The old one may have sheared out a piece of the bottom when it separated or at least forced the hole to get bigger. That rim is probabaly gravely compromised.

You can't weld an extruded aluminum rim without softening it severely.

I don't know about your eyelets, but the eyelets on mavic CXP22 seem to be some kind of rivet, while CXP33 is something else that likes to rattle around inside when there's no tension.

bingo.

yes, aluminum is not a good welding candidate and you are right on with the upper wall of the rim, or outer wall, or rim bed, is now taking the load. with mavic's double-eyelet design, you are completely correct in that the eyelet is to spread the load onto both, inner/outer walls of the rim.

This is also what I initially thought.

However, the wheelsmith that took this project on said that a lot of rims are still single wall-eyelet and that the strength gained from double-eyeletting is marginal when quite a few of these first gen carbones had this issue. He thought, why not get a very strong eyelet that would fit the outer wall and use that instead.

Looking at the cross section of the rim, on mavics service center website, reveals why this is, especially with the tubular rim. The inner rim wall is unlike most box section rims and completely unlike any aero rims that are eyeletted. I will try to get a picture up, but the wheelsmith agrees that this type of rim section could completely rely on the outer eyelet.

http://img268.imageshack.us/img268/9904/mavic.gif

I am not Jobst Brant or anything even close, but has anyone seen a tubular rim profile like this, minus the aero fairing? Structurally we agreed that this design is inherently weak in its design to support only 16 spokes, and half of them radial non driveside.

The rear was completely loosened up and rebuilt all the nipples replaced with SAPIM's more modern/robust design and not the terrible brass pieces that were originally on the wheel. one spoke was replaced with Phill Woods 310mm for the shorter eyelet

Testing has been run on some bumpy roads here, 116psi, rider weight 165lbs, up to 50km/h and has a total of 50km on it at the moment, and the tension is still very even on these spokes and the entire wheel, per side. Still within 1mm of perfect true, radial/lateral.

I doubt its anywhere near as strong as new, but at least its not a boat anchor for a few more kms!

I am going to rehost the pics as picasa doesn't seem to like forums.