Fulcrum Racing Zero 2-Way Fit Clincher Wheelset
Part 1 - Tubed
Fast wheels are a bit of an obsession with us. It's about performance. But it's also a bit about the Solomonic evaluation of pro's and con's as every wheel is about some sort of compromise. Here we turn our attention to the Fulcrum Racing Zero 2-Way Fit wheelset. It's our first extended ride on tubeless technology. But before we address tubeless, we decided it best to address the wheel as a standard tubed clincher wheelset to compare it to what we already know.
Fulcrum wheels look just like Campagnolo wheels. Because they are. You've read discussions about branding on our site, and this naming business is very much of a piece with the labeling of SRAM and Zipp wheels and PRO and Shimano components. People might not want Campy-branded wheels on their Shimano-equipped bike. Maybe it's because we prefer Campy that we don't care if the wheel is branded Fulcrum or Campagnolo. The good thing about Fulcrum is they offer cassette bodies in either Campagnolo-spline or Shimano/SRAM-spline.
The Racing Zeros, on first sighting, look pretty conventional. Machined, anodized rims, red spokes, small hubs. Looks like something you've seen before. But looking at the weight, you can guess something is going on; everything has been looked at and a way has been devised to lighten each piece. While the rim-machining technology is becoming more common, there is extensive machining of the rim on the spoke side and the interior rim wall isn't pierced so you don't need rim strips; you also see this with some Mavic and Shimano wheels. Not piercing the inner wall saves weight by making a rim strip useless, and potentially they've more evenly thinned the wall, so it is lighter and stronger. Fulcrum claims that they've dynamically balanced the wheel with their machining; this means they've used the machining to balance the wheel so the plug where the rim is joined has a counterweight on the other side of the rim by the valve hole. While we can't report we noticed the balanced wheel showing any performance advantages when taking it up to speeds near 50mph, we have spun the wheel with the bike clamped in the stand. The vertical oscillation is definitely reduced with these wheels; how this balancing helps with acceleration or reduces any high-speed wobble we don't know.
The wheels have aluminum spokes and nipples. The spokes probably aren't as aero as a Sapim X-ray (as made famous by Zipp), but between the spokes and the rim, the wheels feel very solid. By this, we mean that we weren't able to cause noticeable wheel flex when thrashing a big gear out of the saddle and with our brakes running very close to the rim. Getting aluminum nipples into a rim with a solid interior wall is a pretty cool trick; Fulcrum includes with the wheelset a spoke wrench and a steel threaded insert and a magnet. If you ever break a spoke, you thread the insert into the nipple and then use the magnet to move the nipple either out of the rim or into place. The spokes are laced radially in the front, with only 16. The rear has 21spokes; 14 drive side and seven non-drive. The 21 spokes are Campagnolo's two to one technology and when you look at the rear wheel from the side, you can see the spokes are gathered in clusters of three, with one non-drive spoke between two drive-side spokes.
The official weight, without skewers, is 625g front, 835g rear. We've weighed some wheels as the same. The test set came in at 620g front (with Mavic wheel magnet) and 820g rear. 10g isn't much, but we'll take the savings. The wheels actually come with their own Fulcrum spoke magnet, which is smaller and more attractive than the Mavic; the one thing is that once you get the rubber sleeve over the magnet, it's really hard to move.
The aluminum-flanged, carbon-shelled hub set is also high-tech but hardly revolutionary. Likewise with the ceramic bearings the wheels run on. What is interesting is that these Fulcrum bearings run on old-fashioned cups-and-cones inside the rim. Many believe cup-and-cone bearing assemblies run more smoothly than pressed cartridges. Thankfully, unlike the old-style lockring-washer-cone setup, the lockring on these wheels doesn't require a cone wrench, but a 2mm Allen key functioning as a pinch bolt. Loosen the Allen, hand-adjust, tighten the Allen, you're good to go.
The quick-release looks pretty ho-hum, but here, too, Fulcrum has made some changes. The cam has been redesigned for a more gradual throw. We'd call the action "soft" as it never feels like the pressure against our hand builds up as we tighten in the fork tips and dropouts. The front skewer weighs 55g and the rear 62g.
Mounting a conventional clincher tire was a bit harder than mounting similar tires on our daily Mavic Open 4 rims. Continental tires, which we can usually mount by hand, take a tool. Vittoria tires, another tire we can usually mount by hand, took more work. While we didn't test out Michelin tires, reports are that Michelins can be tough to mount. Once you start putting air in the tubes, get ready for an aural sensation. You'll hear snapping sounds emanating from the wheel. This is the tire bead snapping into the bead bed. It's a little freaky at first and many think something is seriously wrong. There is an advantage to this snapping. If you run tires with low pressure, chances are the tire won't move on the rim. Likewise, if you get a flat while riding, the beads won't drop into the rim, but will remain stuck in the bead channels. This happened to us one ride when we were riding at about 20mph. We felt pretty confident riding the flat, almost as confident as we feel when we flat a tubular. And, when we stopped, the tire looked pretty much like a flat tubular.
In terms of daily riding, the wheel excelled. We did our usual curb-hopping, pothole surfing routes without taking any special care to ride carefully. The rim never went out of true, nor did we blip the rim or hear any untoward cracking noises after taking particularly bad sections. We wish Campy would reveal the rim weight; we'd love to know how light it is, but even without that info, we're pretty confident that the rim is built well and can take pretty abusive riding without a problem.
Riding fast, they feel pretty fast. We tried to quantify how they compared to our daily 28-spoke box section wheels by riding a hard tempo on our standard 10k loop. Unfortunately, the numbers were inconclusive thanks to dramatically different wind conditions. They were between 10 and 25 seconds faster on different days with the same tires at a power range within 5 watts.
The 26mm front depth and 30mm rear aren't deep by today's standards, and probably aren't incredibly aero, but with the low spoke count, the wheels are pretty fast in the wind. Because of the lighter weight, they feel snappier (accelerating easily and predictably) than a deeper dish wheel, but the Fulcrums probably are a bit slower. Interestingly, the rim is relatively wide, 20.5mm, which isn't Hed's 23mm, but still wider than most clincher rims. Having read Hed's take on wider rims, we wonder if a 23mm tire on this rim is more aero and grippier than on a 19mm rim.
Even without going the tubeless route, the Fulcrum Racing Zero Two-Way Fit wheels are pretty impressive. They can be saved for racing or ridden daily or both.
Part 2 - Tubeless
When these Fulcrum Racing Zero 2-Way Fit wheels arrived, they already had Hutchinson Fusion 2 Tubeless tires mounted. We were all set to pull off the tires and mount our regular tubed rubber, but then we spied a weather forecast. The wheels arrived on a Thursday and the criterium we were scheduled to race Saturday had heavy rains almost guaranteed. We decided to ride the tires Friday and Saturday, then switch.
The rain came early. On our Friday ride, it was already raining. So we pumped up the tires to 95psi (145lb rider weight) and went out for a ride. No problems with road grip. We even rode over to the criterium course and checked out the sweeping U-turn at the north end of the course. Felt fine in the wet. Did it at speed a few times.
Then the rain came hard and with 50mph gusts ripping through the course, the race officials shortened the five-turn course to a two-turn course for safety. U-turn at one end, U-turn at the other.
Before starting, we dropped the pressure in the tubeless tires to under 85psi (we pumped to 85 and it seemed like a little came out when we took off the chuck) and raced. The tires didn't feel squishy and we were totally confident in the turns. We were able to close gaps to the riders ahead and open from the riders behind going through the faster north-end turn. There could be any number of reasons for this; better skill, more practice, a heightened sense of purpose, and/or better grip from the tires. They felt great. And we raced them the following day in the rain as well.
There was only one issue; the front tire seemed to lose air fairly quickly. By this, we mean we'd pump up the tires and within six hours or so, the tire would be too soft to ride. Whatever, they came off and we rode a month with the Fulcrum's as conventional tubed wheels.
The tires are a bit hard to get off. Removing air from the tires doesn't take the beads off the rim; they're still locked in place. We used a Park tire lever to jab between the tire and the rim seemed to unlock the bead; seems that any sharp broad lever should do the trick. Once you've gotten a little bead off, it's easier to work the rest.
Naturally, we weighed the pieces. One Hutchinson Fusion 2 weighed 290g, the other 300g. Advertised weight is 290g. The valves weigh 6g apiece.
Now for a bit about road tubeless in general. Hutchinson pioneered the product and brought the to market in 2007, working with Shimano on the rim. There's no patent on the design, so others can copy at will. Hutchinson has the rights on the "Road Tubeless" designation and it only appears on rims Hutchinson has tested and approved and on tires Hutchinson makes. Hutchinson manufactures the Road Tubeless tires Bontrager and Specialized are selling. Road Tubeless rims are currently made by Shimano, Corima, and Campagnolo/Fulcrum. Alex rims, the Taiwanese rim giant, will have one next, and with that, the deluge of tubeless-compatible rims will probably begin.
Tubeless tires are different from tubed tires in two critical ways. One is the shape of the bead, which is designed to lock into an identically shaped channel. The second is the tire needs some kind of impermeable layer underneath the tire to seal in air. At this time, butyl rubber is used by Hutchinson. There are reports that IRC is experimenting with a latex liner on some tubeless-design tires, but these tires have rarely been seen.
We were told to take a little soapy water and apply to the rim in order to get the tire over the rim sides. Maybe it's because the tire had already been installed, but we found we could do most of the tire by hand, and then used a Quik Stik for the final lifting. In terms of the initial pumping of the tire, it seems that big blasts of air help push the tire out and lock the beads in the rim. A mini-pump probably won't do the trick. Three of the four times we installed the tires, we could use a floor pump and the tire snapped into the rim. The last time floor pump blasts weren't taking, so we took out a CO2 cartridge and used an inflator to blow the tire onto the rim.
On the first re-installation, we found the front still leaked air. Couldn't figure out where or why, so we decided to install goo in the front and left the rear alone. "Goo" is the technical term for the various liquid latex solutions that most people run inside their tubeless tires (both on-road and off). The sealant helps prevent flat tires by staying liquid and constantly coating the tire walls at the wheel spins. When there's a cut and air starts to rush out, sealant will start to get forced through the cut and then start to dry, sealing the hole and keeping air in the tire. Hutchinson recommends their FastAir tire sealant, but any ammonia-free sealant should do. The benefit and difficulty of the Hutchinson product is the lack of control you have in terms of putting the sealant into the tire. Being compressed into a can, you can't squirt out a small quantity or really carefully split the quantity in the can between the front and rear. It's pretty much all or nothing.
We also carry Stan's and Caffelatex. The shop preference of late has been Caffelatex, so we went with that. Caffelatex is supposed to be unique in that the action of spinning the wheel is supposed to make their latex foam up which should mean the solution finds the hole in the tire easier and faster and seals up more quickly. Friends of ours have actually spooned out quantities of Stan's, just like measuring medicine, to put in the tire before finishing mounting. Stan's recommends putting a capful in each road tire.
A capful doesn't seem like a terribly precise measure. We also wanted to weigh the quantity of goo we were installing. We also got the CaffeLatex injector, as precise measuring seemed like a smart idea. If you go the injector route or Fast'Air route, pump up your tire first so the beads seat.
The people at Caffelatex told us that they recommended 30-50ml of their liquid latex per tire. At the same time, they thought the thing to do was to start with about 25ml of goo, see if it works, and go from there.
You open up the big bottle, drop the flexible hose end of the injector into the liquid and use the vacuum of pulling up the syringe to bring in the goo. Before installing the goo, we weighed the CaffeLatex; by our measure, 25ml of the goo weighed 26g.
It's best to remove the valve cores before installing, as the liquid flows more easily and won't clog your Presta valve. But going this route means having to hold the hose firmly around the valve stem, otherwise, the stuff will leak out.
On our first ride, the front was holding fine, but the rear was punctured and wouldn't hold air anymore. So we pulled out a tube and installed it. Turns out, this is a major hassle. Since the bead locks onto the rim, we figured the smart move was to unlock only one bead and the tire would seat better. We figured wrong. We tried and tried, but the bead wouldn't entirely seat. So we rode a lumpy 35 miles before getting home and installing goo. We asked the people at Hutchinson about this. They recommend completely un-sealing the bead before installing the tube so the tire pushes out more evenly.
And the 25ml of goo didn't work in the hole. Our next ride we had to stop several times to pump up the rear tire. Probably we had ridden all the stuff out by the end, so we injected another 25ml of goop. And this time, we found the hole and put the hole at the bottom of the wheel's travel and weighted it so the goo would be forced through the cut until it sealed.
Tubeless at Speed
The next day was actually a big event and we planned on using tubeless. Tour of the Battenkill is now a big and expensive stop on the racing calendar. While we have issues with the cost of the race, it's a fun event and all the dirt roads would be a good test.
We pumped the tires up to 90psi and raced them. These aren't cobblestones, but dirt roads. Not as smooth as pavement, but not terrible. We raced Cosmic Carbone Ultimates in the past with no problem. Still, the Tubeless gave a softer, more comfortable ride, and we didn't flat.
Subsequent to Battenkill, we haven't raced them again, though we've ridden them through all our regular training travails. We pump the tires up to 90psi, largely at the recommendation of the people at Hutchinson, and then don't bring the pump out again for a week. Yes, Hutch' should produce a tire pressure guide and have acknowledged as much. But right now, you're going to have to experiment.
At 90psi, the wheels feel pretty fast, whether it's climbing, descending, or flat-road hammering. Cornering has been a breeze, but we rarely have problems in corners. We can see where people who want to feel better-adhered to the road or want to take the edge of their stiff-as-a-board frame and handlebars would love the lower pressure; for us, it's nice, but we don't notice a huge change. We could probably ride 75psi without a problem and maybe then we'd notice a big change.
We rolled our usual 10k loop, and the tubeless setup on the Fulcrum's seemed to take another 10 seconds off our time compared to the tubed version. And that makes the wheel set-up pretty fast. Rolling faster on tubeless is something that is up for debate. Some proponents will tell you that tubeless should roll faster because the tire will conform to the road better AND you don't have the friction of the tube rubbing on the tire. Skeptics will tell you that the butyl liner stiffens the tire much as a tube would, even though it shouldn't offer the same friction issues between the tube and tire.
Just our luck, Al Morrison, the tire tester par excellence of Bike Tech Review, has just completed the eighth revision (aka "rev9") of his seminal work "AFM_Tire_Testing. If you ever wonder how different tires roll compared to one another, this is the most comprehensive source we know of. He tests Hutchinson Fusion 2's. Surprisingly to us, the tire does not test very well with a Crr (coefficient of rolling resistance) of .331 and taking 16.3 watts per wheel to power. For contrast, the "winner' was the Vittoria Pista Evo CS tubular with a Crr of .002200 and taking 10.8w per wheel to power. A Vittoria Corsa Evo CX clincher with a Michelin Latex tube did .00250 Crr and 12.3w per wheel to power.
Rolling resistance, of course, isn't everything. These tires feel fast and stick well and seem to be as durable as using much heavier belted tires with thicker tubes at a fraction of the weight and give much better road feel. Friends of ours have fallen hard for tubeless, riding the tires until the casing starts to show. They report no flat tires.
There is some care that should be taken. The folks at CaffeLatex recommend opening up the tire every month and checking the liquid latex inside. If the bike's been sitting, the goo could have clotted up. If you've been riding lots, the stuff could be thin and dried to the inside. Just peel off the dry stuff, inject some fresh latex, and that should be all you need to do until the next month rolls around.
Overall, we're impressed with the Fulcrum Racing Zero 2-Way fit wheels with Hutchinson Fusion 2 tubeless tires installed. There's no weight penalty for the tubeless in a package that seems as fast or faster than tubes and tires at the same weight. Nearly flat-proof in a light package is even better. While we'd be selective in terms of what races we'd ride this setup, most particularly using them in bad roads and bad weather, they're superb for a daily wheel package. Considering that we're seeing a real growth in tubeless tires and tubeless-compatible wheels, it's somewhere between conceivable and likely that we'll see big advances in tires and an vast selection of wheels in the near future.