Friday, March 16, 2007

Interesting review.

So I get a weekly newsletter from the guys at www.roadbikerider.com. It's a great website with years of experience and knowledge being shared. Yes, the 2 main contributers are older and are into brevets and not TTs, crits, or road races. They just ride tons of miles so bike parts have to work well, last long, and be comfortable. Having said all that, they recently did a review of the first road tubeless system. I have to cut and paste it because their product review page gets updated every couple of weeks. So here's the review:

Hutchinson Fusion 2
Tubeless Road Tires

www.roadtubeless.com
Price: $60-$65
Source: bike shops, websites, catalogs
Colors:
black, gray, silver
Weight:
290 grams claimed (330 grams actual)
Size:
700x23C (24 mm actual width)
Tread:
slick, triple-compound all-weather with Kevlar
puncture protection

Casing:
127 tpi
Beads:
carbon (folding)
Pressure rating:
120 psi (tested at 100 psi rear,
95 psi front)

Similar model:
Hutchinson Atom, 700x21C,
265 grams (claimed weight)

RBR advertiser:
no
How obtained: sample from company
Tested:
1,500 miles (2,400 km)

HOT!

  • first tubeless road tire sets new standard in ride quality

  • low rolling resistance and excellent cornering

  • easy installation/removal

  • no rim strip or sealant required

  • eliminates risk of pinch flats

  • tire remains on rim when punctured

  • flats can be repaired by installing inner tube

not!

  • test tires were heavier than claimed weight

  • special patches required

Shimano Dura-Ace
7801-SL Wheelset

www.shimano.com

Price: $980 per pair
Source: bike shops, websites, catalogs
Weight:
650/870 grams claimed; 708/907 grams actual
(front/rear without skewers or valve stems)

Rims:
700C aero; 24-mm Scandium aluminum; reinforced
spoke holes; asymmetric and offset rear rim; wear indicators;
compatible with tubeless tires and conventional tires with
inner tubes

Spokes:
16 front, aero stainless-steel radially laced; 20 rear,

radial drive side, cross 2 left side; aluminum nipples
Hubs:
Dura-Ace with oversize 7075-aluminum axles,

angular-contact stainless-steel bearings in nylon retainers,

labyrinth seals; aluminum cassette body with triple pawls

Cassette compatibility: 10-speed Shimano, SRAM
Extras:
Dura-Ace skewers, computer magnet, 2 tubeless valve
stems, 2 spoke
wrenches, 2 Shimano wheel bags, 3-year warranty
RBR advertiser:
no
How obtained: sample from company
Tested:
1,500 miles (2,400 km)

zoom!


zoom!

HOT!

  • stellar Dura-Ace quality throughout

  • first-rate power transfer climbing and sprinting

  • excellent cornering

  • accepts tubeless or standard clincher tires

  • easy tire installation and removal

  • unaffected by crosswinds

  • Scandium rims significantly improve braking power

not!

  • 10-speed only


By Jim Langley

This is an extra-long review
because it's about exciting new technology -- the first road tubeless tire and wheel system. Since spring has almost sprung and you'd surely rather be spinning than scrolling, I'll reveal my verdict at the outset and you can read the details at your leisure.

After more than 1,500 miles on Hutchinson's Fusion 2 tires and Shimano's 7801-SL wheels, I believe most roadies will eventually go tubeless because of how much better it makes a bike ride. Like with clipless pedals in the 1980s, the changeover will come as a wide selection of these revolutionary tires and rims becomes available.

I also believe this road tubeless technology could even sound the death knell for tubular tires (sew-ups). Performance is that good. Plus, there's no hassle factor (keep reading).

Rising from the Dirt

My conclusions are a surprise because when I first heard about tubeless road tires and wheels I was skeptical. Off-road systems came first and I haven't had much luck with them. All the hoopla convinced me to give the knobbies a try and I did, riding dedicated tubeless dirt tires and later trying standard fatties with Stan's No-tubes system, which uses special rim strips and a sealant poured into the tires.

The promises of off-road tubeless include no more pinch flats (among the most common cause of flats on trails); lighter weight because there's no tube; and a more compliant ride with superior traction because you can run significantly lower pressures.

As a Masters Expert cross-country racer, that all sounded great to me. But due to extra beefy sidewalls that are required to trap the air, the tubeless tires were so heavy that my feathery Specialized S-Works hardtail suddenly had all the get-up-and-go of the banana slugs that park on Santa Cruz's trails. Not good. Thinking that Stan's would offer the lightness I craved, I gave that system a go. But messing with the sealant and the hassle of getting the tires to hold air in the first place put me back on tried-and-true tires and tubes for good.

At least off-road.

Road Tubeless Debut

Last September at the Interbike industry trade show I put aside my negativity and hustled over to the joint Shimano/Hutchinson road tubeless booth. I was interested in trying the system because just like when the off-road models came out, all the buzz had caught my attention. And, boy, am I glad it did.

Interbike is held in Las Vegas where the roads are billiard-table smooth. Any wheel/tire will feel awesome. The real test would be on my local loops with their cracked and chip-sealed pavement. I also wanted to find out if road tubeless tires were as much of an installation hassle as their dirt counterparts. So I asked Shimano and Hutchinson to provide me with a pair of wheels and tires to test. Extra thanks goes to Shimano, which also provided the required Dura-Ace 10-speed components. Because the 7801-SL tubeless wheels are 10-speed only, they weren't compatible with my 9-speed Dura-Ace Litespeed. I couldn't have tested the wheels without upgrading the drivetrain.

The wheels arrived first, complete with wheel bags, skewers and special tubeless valve stems, which are easily installed. Tubeless rims can't have any holes inside or air would escape, so there are special aluminum rim nipples threaded into the crown (bottom) of the rims. The spokes are threaded at both ends, a design that eliminates the bend and head where so many standard spokes fail. At the rim they're fully threaded into the special fixed nipples, while the nipples at the hub are used for tensioning and truing. The wheels came out of the box round, true and tight, and in more than 1,500 miles have not required any touch-ups. Shimano supplies a special spoke wrench -- a nice feature if you know how to use it.

The front wheel has the radial spoking found on most aero models. The rear is less common with crossed spokes on the left side and radial spokes under the cassette. You might expect some wind-up with a build like this when you deliver power, but Shimano's engineers felt that the oversize hub and crossed non-drive-side spokes would be more than enough to handle anyone's jump. I've done my best Thor Hushovd imitations and can't feel any give at all. Interestingly, a nice advantage of having the nipples at the hub is that it creates a few millimeters of clearance between the crossed spokes. This guarantees no wear at these points and no annoying tick, tick, tick of metal against metal when rolling along, no matter how many miles you put on the wheel.

Shortly after I received the wheels a teammate also got a pair. He asked me to help him install ceramic bearings, which gave me the chance to look inside the Dura-Ace hubs. It's impressive and surprising how much they've evolved over the years. You now find a somewhat amazing oversize, multi-diameter 7075-aluminum axle, press-in labyrinth seals, stainless-steel bearings in nifty little nylon retainers, and an aluminum freehub body with three sets of pawls. Time will tell if the new design is as durable and low maintenance as Dura-Ace hubs of old, but these sure look engineered to the nines. They're nicely sealed and turn as smoothly as any hubs I've worked on.

Helpful Website

While waiting for the tires to arrive I took Hutchinson's advice and visited their special www.roadtubeless.com site to read about the tires and learn how to mount them properly. I also watched a convincing video with Tom Boonen and others praising the ride. Hutchinson recommends using its special StickAir lever if you have trouble installing a tire, and it suggests applying soapy water to the tire beads to help seat them. The trick with tubeless tires is getting them to seal tightly enough to retain air, so a precision fit is critical. You're told to use a floor pump, CO2 inflator or compressor to fill the tires, not your frame pump or mini.

When the tires arrived I eagerly tore open the box and found that they look identical to any nice folding road tire. They felt slightly heavier and stiffer in the sidewalls, though, so I weighed them. Sure enough, they were 40 grams heavier than the claimed weight (330 grams vs. 290). That's 125 grams heavier than my current favorite road tire and 120 grams heavier than the claimed weight of Hutchinson's non-tubeless Fusion tire. However, 330 grams is in line with some training-level tires, and when you subtract the typical weight of a butyl tube and rim strip you arrive at a similar total weight. So you're not losing or gaining anything. Had the tires weighed 290 grams, or if you used Hutchinson's Atom tubeless tires, which are said to weigh 265 grams, you could actually end up with significant weight savings. It would be right at the rim, too, where you get the most benefit when climbing and accelerating. It's likely that as the tubeless technology is perfected and other companies enter the market, tire weight will come down.

Hutchinson included two FastAir canister-type inflators -- pocket-size compressed-air pumps complete with press-on heads and sealant. But first I had to install the special presta valves in the Shimano wheels. These valves have two nylon pieces that perfectly fit the inside and underside of the rim. They seal tightly when you slip on the O-ring that sits at the valve's base and then screw on the knurled valve nut.

Easy On/Off

With the valves in place, I decided to install the Fusions as I would any tire. I popped them on by hand with no need for soap, the special Hutchinson tire lever or the FastAir with sealant. All it took was a little elbow grease. There is a trick, however -- the same one used for clincher tires: Make sure the tire beads are in the deepest part of the rim (the belly or well) during installation. This is the rim's smallest diameter and ensures you have enough slack to lift the last section of tire over the rim. If you don't take this step, the beads tend to get stuck high on the rim, making it much harder, if not impossible, to install the tire. To remove Fusions, most people will need tire levers. The tires pop off like standard tires and with about the same amount of effort.

The biggest and best surprise came when I inflated the tires with my floor pump. They seated right away and held the air. This seemed like a small miracle after my experience with tubeless knobbies, which you have to wiggle and squeeze and hope and pray the air that's rushing in from your compressor (forget about using a floor pump or CO2) will somehow defy physics and stay inside. I was so surprised I stood there for awhile waiting to hear the hiss of escaping air, and I kept checking the tires every hour to see if the pressure had gone down. Days later the tires were still holding air and they have continued to do so with no more topping off than conventional clinchers.

A Winning Ride

While the ease of installation and inflation is exciting and a testimonial to the fine engineering done by Shimano and Hutchinson to perfect tubeless road rims and tires, it's the ride that I believe will make this technology a hit.

No tubes means more compliance from the tires. This results in excellent high-frequency vibration damping for a dreamy-smooth ride that sets a new standard for comfort. Fusions don't soak up impacts from ruts and potholes; those feel the same as on tires with inner tubes. But on the rough, rumbly pavement so common on secondary roads, Fusions insulate you. They take the buzz out so you feel better during and after rides.

Like the very best tubulars, Fusions sing -- a high-pitched, almost imperceptible tone you feel as much as hear. It seems to be saying faster, faster. And with Shimano's aero wheels, the system does feel quite fast. Fusions grip great in corners too.

When I watched Boonen talk about the tires on Hutchinson's website, I figured he was paid to say what he did. He probably was, but even during my first miles on Fusions I knew he was also speaking from experience. The ride is exceptional and I'm convinced that if you go tubeless you won't go back. Apparently, others in the bicycle industry agree because Campagnolo, Michelin and Continental are known to be working on tubeless products. More companies are sure to follow.

Wear and Tear

I had one rear puncture, a glass cut, after about 1,100 miles. This gave me a chance to test the claim that tubeless tires stay on the rim better than clinchers when flat. I didn't ride far, just to a safe place to do the repair. But the tire did not creep off the rim or make the bike ride too squirrelly. I don't think I'd risk $1,000 wheels riding on a flat, but it's nice to know the tire won't roll off and cause a crash if an emergency forces you to keep going for a while.

The Fusion requires a special patch, which I wasn't able to try for this test so I can't comment on how it works. I did try a standard patch but it wouldn't stick. So I fixed the flat by inserting a standard tube, which worked fine. I had to wet the tire beads with water from my bottle to get them to seat properly with the frame pump.

It's possible that if I had inflated the tires with Hutchinson's FastAir sealant that it might have automatically closed the puncture, but I'm not sure. The glass caused a 1/8-inch hole, perhaps more than the sealant can handle. In any case, some riders like sealants and use them in all their tubes to help prevent flats. If you ride where there are thorns or lots of debris on the road, sealant probably makes sense. In my area I don't have those issues.

Apart from that flat, the Fusions have held up like high-quality clinchers. The rear started to square off at 1,000 miles. Now past 1,500 miles, the tread is thin with a fair number of nicks and cuts indicating that it's almost time to install new rubber. Typically, the front tire has plenty of tread left.

Note: Because riders with experience with Stan's off-road system may be inclined to try it, an important caution is in order: You can't use Stan's sealant and standard clincher road tires. While you may be able to get them to hold air, as soon as you try to ride they'll pop off the rim and you'll probably go down hard. You must use tubeless tires because they have special beads that lock into the matching beads in tubeless rims, which is what keeps the tires firmly in place.

Bottom Line

Even though the Hutchinson/Shimano tubeless system is heavier than the claimed weight and you can't use this setup on your 9-speed bike, I give the tires and wheels almost our highest rating. Much credit goes to these French and Japanese companies for believing in the tubeless road concept, for throwing their full engineering muscle into the project, and for creating a nearly perfect new system that will make any bicycle, even the trickest super bike, ride significantly better. In this era of 14-pound carbon wonderbikes, that's quite an accomplishment.

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