Remove old, perfectly airtight but worn out, Hutchinson tubeless Fusion 2 from tubeless rim. Mount brand new Hutchinson tubeless Fusion 3, inflate and ... it loses 10 psi per hour. Inspect in bowl of water to discover fine line of bubbles escaping from seam in tyre around entire circumference on both sides. Note: not from seal between tyre and rim. Google problem to discover others have exact same problem. Pic from another forum:
http://i938.photobucket.com/albums/ad22 ... resize.jpg
Anybody else heard of this?

_________________
Under the Sun - a thriller for weightweenies with bike loving main character on Kindle here

IF you have not done so already,
Use compressor and inflate that baby up to 140psi, rock hard,
You may have to re inflate a few times, try to get those beads to really lock in. Inflate it rock hard and bounce it a bit, be especially sure it is supple and locked around the stem area.
Then, if you can get them really over inflated and keep them there this helps is break in, and then you can take them back to normal psi in 24 hours and they should stay stuck./

I did get it up that high. The problem is not so much the bead locking in, but more the actual tyre appearing to be porous. But thanks for your advice, which I certainly agree with on these tyres.

_________________
Under the Sun - a thriller for weightweenies with bike loving main character on Kindle here

I run Fusion 3's on a Campagnolo Eurus two-way fit rim and they hold air better than anything I have ever used. I can easily go a week without adding air. I run them at around 85 psi front and 90-95 psi rear. To mount I used soap and water on the bead. I am able to get the tire seated using a floor pump. Don't know if that info helps, but your experience with the Fusion 3's is different from mine.

Also, I now run them with about 30 ml of CafeLatex, which may also help the seal.

That info does help, thanks. The fact that your tyres hold air tells me not all tubeless Fusion 3s have the same manufacturing fault that mine (and others on other forums) clearly suffer from.
I've been running my Fusion2's at 80 psi front and back and love the ride quality. That's why I want to persevere with tubeless. But if Hutchinson can't even build the f***ing tyre properly it's putting me off the idea.

_________________
Under the Sun - a thriller for weightweenies with bike loving main character on Kindle here

Are you using any sort of sealant? Stan's, Cafe Latex, etc? Those small holes that you observe under water will certainly be filled by the sealant, so no more problems. I've got several customers who ride road tubeless with those tires and have had similar results when we try to set them up without sealant (especially after about a month of riding) and some Stan's - about 1 oz. - does the trick every time. A little extra weight...but worth it IMO to have a fully functional, very comfortable riding set of wheels.

_________________
My Rides:
2011 S3 Sram Red/808's/Zipp SLC2/Romin Pro
2009 SWorks Epic/Handbuilt wheels (by me)/Marta SL magnesiums/ XTR drivetrain
2008 Ellsworth Moment/ Handbuilt wheels (by me)/ Marta SL/ X0 (9spd) drivetrain

K.P.A.

my atoms lost maybe 5 psi a day, but no where near the amount you are losing. Once i put in sealant though, they lose maybe 5 psi a week. I definitely think sealant will fix your problem, but the tires should certainly hold air better without.

I'd use soapy water to help the tire bead seat into the rim,

+1 on the

STANS SEALANT<--- very good stuff.

I have the same problem with my 7850 C24 TL and Fusion 3 , mostly with my rear wheel.
But when riding it doesn't seems to loose much air.
I don' know if it comes from the rim or the tire.

Very interesting. This is what I suspected: that some (all?) Fusion 3 tyres leak where the Fusion 2 tyres did not. I've run Fusion 2 tyres for years with no sealant and expected to do the same with the 3s. How can Hutchinson make a tubeless tyre that leaks air through the carcass? A major backward step with their latest tyre.
Anyway, thanks for your input. So the solution looks like ... well ... a solution.

_________________
Under the Sun - a thriller for weightweenies with bike loving main character on Kindle here

I installed Fusion 3s on my Campy Shamal 2-way fit. They hold air great - better than any clincher I've used. I've tried it with and without sealant, and havent had a problem with air leaking, as per your experience.

That's encouraging. Same (brilliant!) wheels as me, as it happens. I've sent the thing back to Wiggle for replacement, so we'll see how another one behaves. I've stuck a standard tube and clincher on for the time being, and the ride reminds me why I like tubeless.

_________________
Under the Sun - a thriller for weightweenies with bike loving main character on Kindle here

Funny how most responses seemed not to have looked at the very revealing photo of air leaking thru the tire away from the bead. Surely these must be duds. I'd exchange them too.

Good news! My replacement Fusion 3 from Wiggle is airtight. That's with no sealant. I've checked the tyre using a bowl of water. No air leaking from the tyre itself, and no air leaking from the rim/tyre seal. It's inflated and appears to be losing no pressure.
What I don't know is: has Hutchinson fixed the problem, or they will continue to produce some good and some dud Fusion 3s?

_________________
Under the Sun - a thriller for weightweenies with bike loving main character on Kindle here

Considering no one has heard of anything even remotely close to what you're describing, hutchinson included, I don't think anyone is really in a position to tell you whether or not this is a bad batch or just an isolated incident. I'm glad that the new ones don't leak, but if you still don't trust the brand/model, try another option.