The special feature of the 30 millimetre wide Zipp Moto rim is the absence of a hollow chamber. Thanks to the flat design, the rim should flex significantly more and therefore be able to compensate for hard punctures. Zipp even promises that the carbon wheelset will be more durable than a conventional aluminium wheelset and can prevent punctures caused by punctures. To emphasise this claim, Zipp even offers a lifetime guarantee on the wheels. The disadvantage of the 1999 euro wheels was their relatively high weight. In 29 inch, the set weighs around 2000 grams. And the 101 XPLR wheels designed for gravel use also weighed quite a lot with the same technology (1620 grams).
New development 1Zero Hitop
With the two new developments Zipp 1Zero Hitop SW and S, Zipp is breaking new ground. When developing the wheels, which are designed for cross-country to light trail use, the focus was on weight. To achieve this goal, the new wheels dispense with the single-walled rim construction and once again rely on a classic hollow chamber. However, with a height of just 21.2 millimetres, the new 1 Zero Hitop should also offer noticeable comfort off-road. With approval for fullys with up to 130 millimetres of suspension travel, the two wheelsets weigh 1325 grams (Hitop SW) and 1495 grams (Hitop S).
Same rim different components
In order to realise two different price points, the two new Zipp 1 Zero Hitop wheels are based on the identical carbon rim with a 30 millimetre rim width, but are otherwise completely different in design. Zipp uses its own ZM2 SL hubs and 24 Sapim CX Ray spokes in the top version 1Zero Hitop SW for 2200 euros. The SW also comes with Tyre Wiz tyre pressure sensors as standard, which weigh just ten grams and work with a measurement tolerance of just two percent. The tyre pressure can be precisely set and easily checked using the Sram AXS app.
The Zipp 1Zero Hitop S wheels, which are significantly cheaper at 1600 euros, have the identical hookless carbon rims, but are each built with 24 CX Sprint spokes. For the hubs, Zipp relies on the ZM 900 SL. Due to the lower price, the Hitop S wheels come without a Tyre Wiz sensor. However, this can be retrofitted as an option for 145 euros. In the overall package, the cheaper wheels weigh around 170 grams more and come in at 1495 grams.
Differences and similarities in detail
Both the ZM2 SL and the ZM 900 SL rear hub work with pawls. However, six pawls are used in the more expensive ZM2 SL and four in the ZM 900 SL. With 66 engagement points, the ZM2 SL is somewhat finer than the 900 SL with 52 points.
Both hub sets come exclusively with a Centrelock disc brake mount. There are two options to choose from when selecting the freehub body. Sram's own XD standard or Shimano Microspline. A Shimano HG version is no longer offered. Zipp limits the wheelsets to a maximum system weight of 130 kilograms and offers a lifetime guarantee.
First driving impression and lab test
BIKE has already had the opportunity to ride the Zipp 1Zero Hitop SW wheelset extensively and even put it through our test lab. The new top wheelset has excellent acceleration and is easy on the throttle. Thanks to the fine ratcheting of the rear hub, every acceleration is very direct. In rough sections on the trail, the new wheels are very forgiving and keep lateral impacts away from the rider.
Our stiffness measurements confirm the good-natured riding behaviour. The lateral stiffness is very low at 36.5 N/mm on the front wheel and 32 N/mm on the rear wheel. For comparison: an extremely stiff wheel such as the Syncros Silverton SL achieves values of around 78 N/mm at the front and 67 N/mm at the rear. For heavy riders, however, the handling could be a little too spongy.
