Zipp 404 braking surface crack

Was involved in a wreck that resulted in my tubular rolling off the back wheel of my 404 in one spot. In that spot, the outtermost carbon layer has "flaked", it's still attached to the rim but a small 1cm x .5cm piece is set to flake right the heck off. The other side of the rim, there is a 1cm hairline crack on this outtermost layer of carbon as well.

I contacted Zipp and they said they won't repair any wheels but would replace the rim under their crash replacement program (around $400). Since it is just this outtermost layer of carbon that is cracked/flaking can I just apply some epoxy to keep the flake from coming off when braking or is the rim trashed?

Other posts and what I've read online all say it's a ticking time bomb and will fail catstrophically if you ride a cracked carbon rim. Wasn't sure if this logic applied as this is more or less just the carbon braking surface that is damaged? If it's trashed I'll just pay the $400 and have a new rim, but wouldn't mind saving that money if the rim is really fine.

Will get input from LBS as well but wanted to see if anyone had an experience like this before.

thanks
John

As the failure mode for composites is often catastrophic, I wouldn't use this wheel again. You have identified cracking, but what about the cracks that you can't see? Perhaps Zipp might be able to assess and repair the wheel?

__________________
"All that we see and seem is but a dream, within a dream..."

I absolutely agree with this, your medical bills could be a lot higher than $400 if this wheel fails without warning.

__________________
Steve
CyclingForums.com

That's what I was figuring. I don't pretend to understand how carbon rims are put together and just seeing the cracking/flaking on the braking surface had me wondering if this surface has much to do with the integrity of the rim or not. (just for braking or had some structural purposes as well)

I'll just send it in. $400 for a new rim and they do all the work putting the new rim on, and returned in 4-7 business days, not bad at all.

Did you finish the race or did you abandon?

How many miles/kilometers did you ride on the wheel after the crash?

I'm very serious when I say there is actually a great opportunity for you/someone to test the post-crash longevity of the rim by using the wheel on your trainer/rollers ... although there won't be any side loads when the bike is on a trainer/rollers, I suppose those could be simulated in other ways.

THEY (i.e., ZIPP) should pay you something for the opportunity to "test" their post-crash rim on the wheel you are sending back to them!

Yes I finished the race and actually took 3rd on my Ksyrium Elite wheels with heavy as can be Gator Skins no less.
The tube rolled off in a spot so I did not ride it at all. After the race I pulled the rest of the tire off for inspection of the rim for damage.

CSC/Saxo Bank would crack rims in races like Flanders or Perry-Roubaix and only discover the small cracks after the race while the wheels held up perfectly. But they don't continue to ride them after that is found of course. I'm sure Zipp has all the cracked rims they could want for testing purposes

FWIW. It might not cost much more to buy a replacement 404 rear wheel via eBay as ZIPP is charging for the replacement rim ... I suppose the rim surface and/or decals might not match your front wheel's cosmetics, but it's something you may want to investigate.