As promised, here’s our followup to the “official-ness” of Road Tubeless.  With wheel support from Shimano, Campy, Roval, Fulcrum and A-Class, as well as interest from folks like Stan’s NoTubes, the question isn’t whether there’s industry support.  Rather, it’s why go tubeless on the road?
The obvious question is “why would I want to run lower tire pressure on a road bike?”
Well, for answers, I went straight to the source.  Steve Boehmke (formerly of RockShox and Shimano and a Mountain Bike Hall of Famer) is a marketing and product development advisor to Hutchinson and has been the man behind promoting this new technology.  He gave us the scoop…there’s more to it than just lower pressure.  Read our interview when you click “more“…
BIKERUMOR: First, the obvious ones.  From a technological standpoint, what’s the difference between the tires and rims on regular road wheels and tubeless ones?
STEVE: Tire differences are:ÂÂ
- Shape of bead on tire and rim. More angular bead shape on tire and rim. That’s why they recommend soapy water during installation to help the bead move and “lock in.”
- Rubber compound used in the bead area of the tire.
- Carbon beads in the tire (That keeps the tire beads to an exact size and doesn’t allow stretch as normal folding beads can) Allows ride-flat safety.
- We recommend using plastic tire levers which won’t damage the bead and affect the ability for the bead to properly seal.
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Rim difference: Rim bead is also more angular in shape. Whereas a tire with a tube uses the tube for a seal, the Road Tubeless technology requires a air-tight seal at the bead (obviously).
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BIKERUMOR: Most people I’ve talked to assume that lower pressure will give the bike a “riding through mud” feel, as though you’re wasting energy with all of the tire deformation that occurs when you run lower pressure.  Heck, even automakers were recently saying to run your car tires on the high side of recommended pressures to help save fuel.  With that in mind, how would running lower pressures increase efficiency on a road bike?
STEVE: Cars have suspension, to begin with… Before suspension they probably recommended running lower pressure for a smoother, faster ride… Super-hard tires deflect off of inconsistencies in the road, leading to wasted energy and a skitterish ride, robbing you of forward propulsion and making you fight the bike. Lower pressures bring a “flow” to the ride.
In the past, running lower pressure in your bike tires ran you the risk of getting pinch flats. Without a tube, this is no longer a concern. Mountain bike riders have been extolling the virtues of lower pressures through tubeless for years now. Cyclocross racers ride with as little air pressure as possible. With road it seems to be more subtle (running 10-20 pounds less than tubed versions…)
BIKERUMOR: How do these tires offer lower rolling resistance?
STEVE: The elimination of friction between the tire and the tube seems to provide a lower rolling resistance (think of how much faster tubulars are…) Tests by Specialized using their Roval wheels showed a 30% decrease in resistance. We are also able to run at much lower pressures (86-100 psi), which lets the wheel roll directly over variations in the road, instead of bouncing off of them (like when you have rock-hard 120 psi tires…) The end result is faster, and you can feel it immediately when you ride the system.
Cyclocross magazine did some tests on this with the cross tires, and found serious increases in speed with less pressure.
BIKERUMOR: How do they better resist puncture?
STEVE: We recommend using Hutchinson Fast’Air latex to seal the bead, and it provides puncture repair if you do make a hole in the tire. Also, we’ve had numerous people get flats without sealant on the road, and they rode back over 5 miles on a flat, staying with the group. The tires don’t come off when deflated. Of course if you had a catastrophic cut into the tire, that might mean calling a cab, but I don’t know anyone who’s had that problem in the few years we’ve been making these tires.ÂÂ
Last resort you can put a tube in! No biggy.
BIKERUMOR: So, you can ride home on a flat…is this a selling point that Hutchinson uses, or is it just a nice fringe benefit.  How does the tire react to this?  Does it destroy the sidewall after a few miles?  Will the tire really stay on the rim around a good corner, even if the flat’s on the front?
STEVE: Not a selling point, just a side benefit that some riders have told us. Not recommended, and probably does serious damage to the tire. But yes, people tell me the tire will stay on, even on the front… (Editor’s note: Hutchinson’s website does list “ride flat safety” as a feature on the Fusion 2 model)
BIKERUMOR: Do you need to use a sealant like the Fast’Air with road tubeless tires, or will they hold air on their own?
STEVE: We recommend that you use a sealant, but I know people who haven’t. They just need to fill their tires up more often. I like the sealant for it’s flat repair properties.
BIKERUMOR: Are the tires more expensive than standard road clincher tires?
STEVE: Yes, about $92.00 versus $64.00 for Tube Type… on the Fusion 2 version…
BIKERUMOR: Lower rolling resistance…less friction…puncture resistance and self healing (with the Fast’air sealant)…any other benefits worth mentioning?
STEVE: Nope, looks good, and thanks!
That concludes the interview…and I thought I’d try reducing the pressure a little in my regular, tubed clincher road tires just to see what happened.  I normally run 120psi (I weigh 180lbs) and dropped it down to 110.  I must say, the ride was a little smoother and I felt every bit as fast…actually had some really solid rides.  And the bike cornered confidently.  I think there’s something to this Road Tubeless thing…
Now, just for fun, here’s a little promo video Hutchinson has on their site that has absolutely nothing to do with tubeless tires, but it sure gets you in the mood to go ride around the city.
