I’ve been riding Shimano Dura-Ace Road Tubeless wheels since 2007.  For a long time, there was only one road tubeless tire made, the Hutchinson Fusion2 - read about that here. A while ago, Hutchinson introduced the Atom to the road tubeless line up.  I’m behind writing up my opinions of the Atom but the tire is excellent.  The Atom is truly a race caliber tire in my opinion and while listed as a 700x23 it is either slightly narrower than that or the Fusion2 is wider.  It could also be the geometry of the tire is just different.  The sidewall seems to come straighter from the rim to the tread.  The Atom is a bit lighter than the Fusion2 and it does feel like it spins up quicker but I’m not sure that is due to the slight weight difference.  Rather, I think it has to do with the Atom being more aerodynamically efficient.  At high speeds such as decents or sprinting, the aero tug on the front wheels is noticeably reduced versus the Fusion2 and other 700x23 clinchers I’ve used.  Part of this feeling could be weight but it’s also noticeably easier to handle in heavy cross winds leading me to believe it is more a reduction in drag.

Until recently, I’d not yet had a puncture flat while running the tubeless tires.  I’ve also never used any sealant in the tires.  My early impression of the Fusion2 was that they wore quickly and cut easily but that never turned into flats even when I rode them past the point when a reasonable person would have replaced them.  I also found that the last few sets seemed to last longer than the first few sets - perhaps 1/3 more.  I may have been too critical early on or perhaps the tire was being improved on it’s way to becoming a Fusion3.  The Atom does, as one would expect from a race tire, wear quicker than the Fusion2 but is on par with what is expected from high end clinchers.  I did finally have a puncture flat while using the Atom though I hesitate to judge the tire too harshly.  Were I not both in testing mode with tire (just how far can I push it) and being lazy since winter was upon us, I would have replaced the tire a couple of hundred miles before I got the flat.  Also, the flat was caused by a rather stout thorn or wood sliver that would likely have punctured any race tire more than half worn.  Sometimes, we just get flats but I’m still pleased with both the wear and puncture resistance in comparison to my usual expectations from a race tire.

The Atom is very supple and offers improved cornering and comfort at the same air pressure versus the Fusion2.  This is to be expected from a single compound racing tire and Atom delivers beyond what I had hoped.  Road Tubeless or not, the Atom ranks right at the top of my list of not-tubular tires.  In fact, I’d love to try the standard clincher version for a direct comparison to the excellent Continental GP4000.

For the reasons mentioned in my earlier review of the tubeless set up, I am a big fan of the concept.  While tubulars are still the gold standard, the Atom closes the gap on feel and performance substantially.  Even if there is still a weight penalty with road tubeless, there is still a bigger convenience penalty with tubulars.  As soon as there is a readily available, high performance aero road tubeless option, I will likely make it my next race wheel.  I can find a review or two on the Hutchinson aero road tubeless wheel online but I can’t find any place selling the wheel nor can I find it on Hutchinson’s own web site.  There are numerous broken links on the site including the one marked “wheels”.  At this time, I don’t know of any other aero road tubeless wheels in the market place so I’ll likely have to wait a while. 

There are kits and instructions out there for converting standard clincher wheels to road tubeless.  I generally like things to be used as intended from manufacturers so I have no interest in trying that.  However, there are some noted experts out there who say it can be done easily and safely should you wish to give it a go.

Finally, you may notice that I refer to the Fusion2 when there has been a Fusion3 for a while.  I have only ridden the Fusion2 and didn’t want to comment on the Fusion3 until I ride it.  I also didn’t want to confuse the issue of comparing tires I’ve spent a lot of time riding.  Also, Specialized does list their own road tubeless tires.  It is my understanding that those are rebranded Hutchinson tires but I am not positive about that.  However, the S-Works Turbo Tubeless looks remarkably like the Fusion3 so it seems likely.  In any event, it gives us another source for product.

Mark