Pretty much any high-end mountain bike wheel is claimed to be laterally stiff but vertically compliant, thereby offering precise cornering while remaining comfortable over bumps. Most carbon wheelsets are wildly successful with the first claim, but not the second.
Zipp makes the same claims and more, having designed its rims in a radically different way. The 3ZERO Moto is a single-wall rim, as opposed to a hollow, box-section rim with a D-shaped cross-section.
The single wall rim has a flat cross-section. The rim on the left is an early prototype, while the right is the final rim shape Rupert Fowler/SRAM
Zipp claims this broad but shallow rim not only provides more vertical and less lateral flex (for the same reason an I-beam is stiffer in one direction than the other) but also allows the rim to twist locally. Zipp calls this third type of flex “ankle compliance”.
You may have noticed that when you get a pinch flat or dent a rim it’s usually on just one side. That’s because in the real world you’re usually going to hit one rim bead harder than the other, because rocks aren’t square.
The rim is designed to twist along the axis of the spoke bed, helping to prevent punctures Zipp
Zipp claims its flat rim profile allows the rim to twist around the axis connecting the spoke holes when impacted on one side, reducing the force on the impacted bead. Zipp also claims the rim twisting allows the tyre to comply to the terrain better when the bike is lent over in a turn, like the ankle joint of a runner.
According to Zipp, these wheels provide measurably less vibration at the handlebar when riding over rough terrain and are more resistant to large impacts in lab-tests than competitor carbon wheels (it wouldn’t say which wheels).
Further, Zipp says it will sustain impacts which would destroy a competitor alloy wheelset in the lab without even denting and that pinch flats are far rarer thanks to the rim being able to twist and flex out of the way. The rim also sports thick (3.75mm) bead walls, which should help to reduce pressure on the tyre in a pinch-flat scenario.
At this point it’s worth pointing out that single-walled rims are nothing new, having been used for decades on budget bikes and, as the 3ZERO MOTO’s name unsubtly suggests, motorbikes. Bouwmeester Composites even did a similar trick with carbon over four years ago. But Zipp is arguably the first big brand to offer single-wall carbon rims to the mass market.
The wheels use 32 J-bend spokes on Zipp ZM1 hubs Rupert Fowler/SRAM
Rim aside, the complete wheelset is otherwise rather traditional. 32 J-bend Sapim spokes are laced in a three-cross pattern. The Zipp ZM1 hubs are essentially the same as SRAM’s XO hub, with 54 points of engagement and stainless-steel cartridge bearings.
The only odd thing about the wheel build is that loose washers sit between the rim and the nipple to spread the load from the spokes, and a nylon rim strip sits under the rim tape to stop the spokes poking through the tape when the rim is flexed towards the hub during an impact. (This is a problem box-section rims avoid as they have a gap between the spokes and the rim tape).
Zipp claims the wheelset weighs 1,825g in 27.5in and 1,910g in 29in, while the rims weigh 535g and 565g respectively. The rims come covered by a standard two-year warranty.
The rims are made in Zipp’s facility in Indianapolis. Wheelsets for the US market are built there too, while those for the European and Asian markets are assembled in Portugal.
Complete wheelsets are shipped with integrated TyreWiz pressure sensors Dan Hearn/SRAM
Rims are available to buy individually, costing £670 / €750 / $700 each. They come with firm recommendations regarding spoke type and spoke tension.
The complete wheelset costs £1,875 / €2,099 / $1,999 a pair. The wheelset includes a version of Quark’s TyreWiz pre-installed, which sits neatly into the inner rim bed and sends accurate tyre pressure data to your phone or bike computer.
The app even allows you to set your ideal pressure and the rim sensor will flash green if it’s in the correct pressure-window; or it will flash red fast if it’s too high or flash red slow if it’s too soft. It’s pretty handy if you’re a pressure obsessive.
Zipp 3ZERO MOTO ride impressions
To get a feel for how the Zipp wheels ride, I tested them back-to-back against my current favourite wheelsets — DT Swiss’s EX1501 30. I rode them for several runs each on the same track, the same day, same bike, and with the same tyres and tyre pressures.
The alloy DT wheels weigh 1,868g in 29, so are 42g lighter than the Zipps based on claimed weight. Of course, that’s not enough weight difference to notice. For a system weight (bike and rider) of 100kg, you’d need at least a 500g difference in combined rim weight to make a 1 percent difference to acceleration.
While quieter, I couldn’t perceive a difference in comfort or traction compared to a DT Swiss alloy wheelset Rupert Fowler/SRAM
On the trail, I couldn’t tell much difference either. The Zipp wheels were noticeably quieter while barrelling through pinball rock sections, but in terms of hand comfort I couldn’t say one wheel was better than the other.
Traction is another area that’s hard to judge. On the dusty trails in Sintra, Portugal, cornering grip is quite limited and so I suspect there wasn’t enough force being generated for wheel flex to become significant. Perceived traction can be affected by tiny differences in factors such as precise line choice, entry speed and body position, all of which are hard to keep consistent enough to notice any difference deriving from wheel flex.
It’s not surprising that the 3ZERO wheels feel no more comfortable than a lightweight set of 28-spoke alloy wheels. Even Zipp’s own claims about real-world accelerometer tests suggest only a slight comfort advantage compared to carbon wheelsets of its choice. However, I certainly wouldn’t say the wheels are harsh, and they offered plenty of support through rocky bomb-holes and berms. They also shrugged off (accidentally) landing a meter-high drop directly onto a large root on a subsequent ride.
They are plenty precise in turns though, and if they prove as tough and puncture-proof as Zipp claims, they could be worth considering Rupert Fowler/SRAM
While the 3Zero Moto is almost certainly more compliant than most carbon wheelsets, it’s no lighter and as far as I can tell no comfier than an alloy DT Swiss wheelset, which costs a little over half the price.
Having said that, if Zipp is to be believed they may stand up to more abuse than an alloy wheelset without picking up dents which, while great for bragging rights, compromise tubeless sealing.
If they really do make punctures less likely that could make all the difference if you’re a keen racer. We’ll get back to you when we’ve had time to work out how much truth there is to these claims.
Zipp 3ZERO MOTO MTB specifications and pricing
Zipp’s first MTB wheelset brings an unusual approach to carbon wheels Dan Hearn/SRAM
Weight: 1,825g (27.5in), 1,910g (29in)
Spokes: 32 J-bend Sapim
Extras: A version of Quark’s TyreWiz pre-installed
Price per rim: £670 / $700 / €750
- Price Price per set: £1,875 / $1,999 / €2,099