Vince Canepa

I purchased a set of Dura Ace WH-7850-C24-TU tubeless wheels in March of 2010. The tires were installed by my (well respected) LBS. The rear slowly started to leak air after 6 months or so. By July of this year it would lose 2 bar overnight. At the same time I picked up a 10 mm cut in the rear tire so I had the same shop break down both wheels and tires, clean out the sealant, mount the new rear tire and remount the old front tire. The rear still had a slow leak which became worse. By November it would lose 4 bar overnight. Frustrated I tackled the diagnosis myself. I found the bead leaking on three areas, so I marked them on the brake track. I pulled off the rear tire and cleaned the rim. What I found was widespread corrosion, with moderate corrosion of the bead are where the leaks were occurring. I cleaned the rim thoroughly with Scotch Brite and remounted the tire. The bead was tight, but the tire would lose 4-5 bar overnight. On investigation I could hear air leaking into the void space between the carbon reinforcement and aluminum rim (when I put the drain holes in the carbon up to my ear). I removed the tire and spent some more time with Scotch Brite. I found 31 pits so severe that I considered them as suspect. Under a magnifier I found one pit with a tiny hole through the aluminum. The front is also corroded by not nearly as bad. Also, when I examined the bead area of the new rear tire I can see evidence in the form of impressions in the rubber of the bead area leading me to believe that the corrosion was there in July when I had the tires replaced/resealed at the LBS.

The only thing I can attribute this to is the sealant. Unfortunately I don't know what the LBS used and, due to the fact that this is the latest in a series of "missteps" by the LBS, I don't trust them to tell me the truth. Shimano has refused to warranty the wheels due to the use of sealant - they have a warning not to use "alkaline" sealants in their instructions. I am working with another LBS to have the rims replaced (the rims are NOT cheap). I really don't want to go through this again, not just because of the cost but my bike has been down since Thanksgiving.

I would appreciate any insights from folks here on BF. Please don't head off on a tangent about the merits/demerits of the tubeless system. I really want to hear about your experience using sealants in these rims. Shimano America told me they don't recommend sealants, but if I have to use it the guy on the phone said to use Caffelatex. Any problems with that product?

qqy

Unfortunate, but why not just ditch the tubeless tire and run a conventional tire and tube? Those are great wheels, and can run either.

Commodus

Seems pretty clear the LBS wrecked your wheels. Of course Shimano isn't going to warranty them. Your claim is with the LBS. Go and be polite. If you don't get satisfaction, be less polite.

I don't know why you're asking about sealant? Seems like you got the answer right from Shimano, surely they know - it's their wheels we're talking about.

Vince Canepa

I am asking about the sealant because I have been getting conflicting answers locally. The Shimano Rep in NC said it was a warranty issue and told the LBS to use Stan's. Shimano America obviously doesn't agree with at. A lot of local riders apparently use Stan's. The use of sealant makes the tires pretty much bullet proof with respect to flats hence the desire to use it.

qqy - Yes I could just throw tubes in them but that precludes being able to run lower pressures. The rough roads around here make that very desirable. I run 5.5 to 6 bar in the front and about 6.5 in the rear. With clinchers I need to run about 8.

Commodus - I tend to agree the first shop is a likely candidate to have caused the damage. However, without some evidence it is just an argument. That is why I posted this query, to see if others are having any similar issues and to form a solid position.

Commodus

Ah... I see. Wish I could be more help. Sounds like you're getting the real runaround here.

Dfarlow

Have used the same wheels without issue for almost two years. Not sure why so many on BF recommend using latex sealants, but my LBS highly recommends against it, as does Shimano. I became a Shimano fan all over again after breaking a spoke while racing my backup bike, hitting the brakes to avoid a pileup just in front of me and toppling over another bike. There was an issue installing the replacement spoke so the wheels were sent back to Shimano - who proceeded to ship a brand new wheelSET (yes, a set), no questions asked. I was shocked. No more red spoke nipples, but a two year old wheelset replaced for free! I'll take it. By the way, never used them with tubes...yet.

knowledgdropper

It certainly sounds like an issue to be resolved with the LBS. I've had mine for almost 2 years, I think, with no issues. FWIW, I've always used Caffelatex since new. The wheels lose about 3-5 psi over the course of 2 weeks, or so.

hawiken

Leonard Zinn at Velo News has written pretty extensively about this. His recommendation is to use CaffeeLatex.

For what it's worth, I bought a pair of 7850's on ebay, that came with tires installed. They were 7850 clinchers, not the TL's, but had the Stan's tape and sealant, and Hutchinson tubeless Fusions. Long story short- the tires were pretty hammered, so I decided to remove them and install clinchers, and was shocked to see the amount of corrosion under the Stan's tape- powdery, flaky stuff, and there was a big ball of corrosion on top of each spoke nipple. The rear wheel was in worse shape than the front. I did the same thing that you did- used a Scotch Brite and alcohol to clean them up, dripped chain lube on the nipples (which removed the corrosion), installed Fusion clinchers and tubes and have been totally impressed with the wheels. The hubs are works of art.

I wasn't too happy with the seller, though, who had advertised the wheels as having been 'ridden for less than 900 miles, no issues, round and true with smooth bearings'. My A$$. Had to true both of them and replace the bearings and axle on the rear. One of the maybe 3 purchases that I've made on ebay that was less than satisfactory.

Vince Canepa

Thanks guys for the insights.
DFarlow - If I read you reply correctly you are running without sealant - right?

Brazos

I have been running Stan's in my Ultegra 6700 wheels for a year. I have not noticed any corrosion but have not have my tires off in a while. I may take one off just to see as I am sure my Stan's is close to dried up anyway. FWIW I had heard on threads like this that Shimano would not warranty their wheels if sealant was used but absolutely nowhere in the literature that came with my wheels was the use of sealant ever mentioned. Therefore I would expect Shimano to warrant the wheels if corrosion started. They has plenty of other warnings but nothing about sealant.

mmmdonuts

I think your claim is with the first person (LBS?) who put the sealant in your wheels. They should make it right with you and then it is up to them to sort it out with Shimano and their reps.

Vince Canepa

Shimano specifically says not to use "alkaline" sealants in the tech documents for the DA wheels. I don't know about Ultegra.
As for the original shop they are claiming they use Caffelatex and have never had a problem. So far It seems like the only way to get my bike back on the road is to suck it up and buy another set of (inexpensive) wheels while I slog through the process of getting the DA wheels repaired. Shimano America is emphatic - use sealant - no warranty. But if you must use sealant use Caffelatex (wink, wink).

Brazos

Out of curiosity I removed my tire from my front Ultegra 6700 wheel earlier to see if I had any corrosion. I have had the wheels for a year and a half and put Stan's in the front wheel about a month or two after buying the wheels and have never touched it since. I found no corrosion just dried up Stan's. I cleaned it up and just remounted w/o sealant. I will probably remove the rear tire soon and check that one. I think there is still some Stan's in fluid form in my rear wheel as some came out the other day when I aired up the tire. As I mentioned above my 6700 wheels came with nothing addressing the use of sealant. I have read stuff on the internet where people have called Shimano and asked and Shimano says it will void their warranty. I can understand Shimano's stance on this as they don't know what homebrew sealants might be used or what new sealant products that might come on the market in the future.

Vince Canepa

I looked up the service instruction for the Ultegra wheels on Shimano's website. The Ultegra wheels do not have the warning that is contained in the Dura-Ace service instructions. I am speculating that the aluminum alloy in the Dura-Ace rim is different than that in the Ultegra rim and is more susceptible to corrosion. Since the Dura-Ace rim is reinforced by the carbon, Shimano may have made the aluminum of a different alloy to reduce weight while still maintaining strength.

pbd

I don't remember where I read it now, but I seem to remember some indications that some soaps can cause this corrosion. Many people use soapy water to mount tubeless tires, and I seem to recall reading that the soaps used can sometimes cause these problems.

Did the LBS use soapy water when mounting the tires?

Vince Canepa

pbd - I don't know for certain what they did.

nhluhr

Because at this point there is more than just air-tight to worry about. It's highly likely that those wheels will fail prematurely thanks to the all the corrosion.

volosong

I've been running the same wheelset as you for this past season, but with tubes. Got got a set of Ultegra tubless wheels for my other bike, but will run tubes in them too. What are the advantages of going tubeless? Seems like a hassle to me, with having to use sealant and the periodic cleanup.