I spent the last two seasons happily using tubeless Stans NoTubes ZTR 755 rims with Hutchinson Bulldog tires and Stan's sealant. It worked great and I could keep my tires at 25-30psi while weighing around 200-220lbs myself (pinch flats happened all the time to me before going tubeless).
Well, after a couple years, I finally destroyed a Bulldog tire on some sharp rocks on a course that cut through the tread. I bought some brand new tires and they say they have a carbon bead like Hutchinson advertised at Interbike this year.
After an hour of wrestling with the tires, I just barely got them on the rim, and half an hour later after putting about 30 psi into them, the bead just sort of exploded off and the tire ejected itself off the rim.
I think I might be going tubular finally, the new tires just feel too small for Stans rims now.
From what I have seen online, Stan's made their rims slightly larger this year, in order to fit more tires that weren't designed for tubeless use. At the same time, Hutchinson made their tires slightly smaller for a better fit (on rims like the DA tubeless). The combination of the two size changes may have made the Stan's/Hutchinson combo less workable.
That's just what I've seen on this forum and others. I have no personal experience with that combo. I'm rocking HED Ardennes rims converted with Stan's Raven CX tire at 30 psi no problem. :)
Having put hutchinsons on stans rims before, it was pretty difficult, but I think you may be right that they made the tires seemingly smaller because they just seem impossible to mount now.
How do the raven tires hold up in bad conditions? I ran those tires on my tubeless 29er with Stans rims and they worked ok but I never rode in deep mud like I sometimes have to race in, and the tread seems almost bald in comparison to most cross tires.
Not to derail the thread, but the Ravens are ok. I saw a short review in Bicycling magazine that described them as good for fire roads and similar gravel or dirt roads, and I would agree. I race mostly on grassy stuff or on pretty buff singletrack and I often find myself wishing I had a more aggressive tread.
Given the Hutchinson tires are both slightly more aggressive than the Raven, and also tubeless, I had actually been thinking of getting a pair of either the Piranhas or the Bulldogs. I'll probably get through this season on the Ravens and then mess with another tire. The ravens are pretty fast on pavement or grassy terrain, they just leave a little to be desired in off camber stuff or more aggressive turns.
I ran last year's (non-carbon) Bulldogs and had no fit or burping issues using a tubeless conversion, a little tight but not too bad. For this season I got a pair of this years carbon bead Piranhas and had the same issue as you've had. I tried for a couple hours to get one on to a Reynolds Solitude. After breaking three tire levers and getting seriously frustrated I actually broke down and took them in to the bike shop where they struggled as well, breaking another tire lever, then eventually breaking the bead as the tire detonated in the process of trying to get it on the rim!
They warrantied that tire, and I went back home and eventually got them on to a pair of Roval Paves, pretty tough but doable. I think the Rovals might have a slightly deeper channel that allows the opposite side of the bead to drop in more. They seated up tubeless with Stan's and have been working great at 32psi, love the tires but man those things are a bitch!
hey guys - we have an early (the very first) review of the carbon bead tires in issue 10 and lots of other tire reviews in that issue 10, as well as issue 3 (almost every tire available has been reviewed in those two issues, including the raven).
here's my brief opinion though - on stan's rims, you can get by without the carbon bead, and you should be able to find a lot of those still around. it's really hard to tell though even when side by side.
hutchinson has assured me that the bead size (tightness) is exactly the same, only the material has changed for even less stretch. but like you I swear it feels tighter. it definitely does better on the rim it was designed for - the road tubeless rims like Shimano and Fulcrum. before, the results were pretty unacceptable from a low pressure perspective. now i've found it pretty burp-proof. they've done fine on the new stans 340 as well, but the old tire did well on stans so I can't say it's any better on that rim.
I did break one tire lever once trying to get them on. and I agree that soapy water is essential as these tires have a tendency to seal up but not be completely seated (part of bead sits too low). it's required 80+psi to seat them.
the only test I haven't fully completed is to see how they perform as conversions. but a rough course this past weekend shredded two of mine, just like matt, so I'm down to just one more. let's see if I can patch these tears as well.
Did you warranty through the shop? My Bulldog bead gave up the ghost during mounting as well. Easton Ascent II's, converted with a Stan's kit if anyone's curious. Ignore Stan's advice about leaving the rim strip on for those wheels—the tire won't go on unless you take it off (or you break the bead). That should go for Velocity Aeroheads as well, since they're pretty much the same rime.
Returning to the thread, I have finally managed to get the front wheel set up (rear rim has a ding that won't seal) with the undamaged tire of my pair and it's holding air well, even without sealant. Fit is very tight—can't hand burp it at 35psi. Haven't put it through it's paces yet.
The broken-bead tire, meanwhile, won't seat correctly, even with a tube. Probably not going to field-test that setup.
Finally got out and rode on the one undamaged tire (running front)—gotta say it was pretty nice at ~32psi. I'm 165 with a bad track record of flats and I've been exclusively on clinchers before.
Got a little seeping on the (paved) ride out to the West Hartford Reservoir, but when I starting hitting the bony stuff and hard corners on the grass, I got no burps, and the tire had good give on roots/rocks. Lots of bite in the corners, too—took a while to get my head around how little I needed to brake on pretty familiar terrain.
But again, my only prior experience was a pair of clinchers, in use since 2006.
The new tires absolutely fit tighter, or are at least less stretchy. I was running a conversion with American Classic Hurricanes and Pre-Carbon Piranhas, but found they easily mounted by hand, and when not inflated, you could easily lift the bead of the tire from the rim bed (which is shallow in the Hurricanes). When inflated, you could easily burp the tire (tiny squirt of sealant) by pinching firmly, or pressing the bead off the rim laterally with your thumbs. I raced a few races like this, and found dozens of sealant squirts on the sidewalls from tiny burps. Building up the rim bed with more tape only gave minimal improvement.
After pinching a hole through a tire, I bought a 2010/11 Carbon bead tire, which was tighter, but could still be mounted by hand (but difficult). Now the tires seal like a champ. I rode a bumpy course at 28 psi (165lb rider) and didn't have a speck of sealant.
For me it is much better, but it probably depends on the rim you're using.