Ibis S35 Logo Carbon Boost Review
Cons: 10-degree freehub engagement
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Our Analysis and Test Results
Ibis is best known for their bike frames, but they have been producing a line of carbon and alloy wheels for some time now. They were among the first brands to adopt the wider is better rim philosophy, and they helped to set the trend of pairing wider rims with wider tires. The S35 is a new rim design that involves a collaborative effort between Ibis and Stan's NoTubes. Ibis brought their carbon fiber and wide rim expertise and combined that with Stan's Bead Socket Technology with the goal of creating a lighter, stronger, and higher-performing rim. Testers were most impressed with the traction that these wider rims helped to provide, and we awarded them our Top Pick for Traction.
The S35 Carbon wheels are based around Ibis' new S35 carbon rims. These rims were designed in collaboration with Stan's NoTubes and they have incorporated Stan's patented Bead Socket Technology (BST) into the design. The BST design features a shorter bead-wall that is said to be lighter weight and more durable. These asymmetric Toughened Hybrid Carbon rims have a 35mm internal rim width, a 41mm external measurement, and a 5mm spoke offset. Ibis claims the larger offset allows them to improve the bracing angle of the spokes while maintaining even tension for a stronger and more durable wheel. The 35mm internal rim width is the widest in our test and is intended for use with tires in the 2.35"-2.8" width range.
The rims are laced to the Ibis Logo hubs with 32 j-bend D-light spokes. The Logo hubs have 4 Enduro brand bearings and a six-bolt brake rotor mount. The freehub mechanism has 4-pawls paired with a 36-tooth drive ring resulting in 10-degrees between engagement points. They are offered with Shimano, SRAM XD, and MicroSpline freehub drivers. The rims are covered by a 7-year no-fault warranty and the hubs are backed by a 2-year warranty.
Each one of our testers used the word "traction" more than once when describing the ride quality of the S35 Carbon. Starting from the first corner, the difference in traction while riding these wheels was immediately noticeable. The other heavily used words in the ride quality descriptions were "damp" and "comfortable". Ibis did an excellent job when designing these rims, and the width, offset, and shallow profile all combine to provide a nicely balanced, well-damped ride with the best traction of all the models we tested.
One of the biggest factors influencing the ride quality of the S35 wheels is the rim width. At 35mm, the internal rim width is 4-5mm wider than most of the other models in the test. That may not sound like much, but it truly does make a difference. The wider rim makes the tire beads farther apart which increases the air volume of the tire. The increased air volume allows you to run lower pressures which increases the cushion of the tires and the size of the tire's contact patch. We say that about most wheels with a 30mm internal rim width, and it is even more true with the 35mm width.
The S35 Carbon rims are asymmetrical with a 5-degree spoke offset and a shallow rim profile. Testers noted that they felt stiff enough, yet they offered a well-damped feel that helped mute trail feedback. Compared to some of the stiffer carbon wheels had a tendency to deflect and sometimes even feel a little harsh, the S35s provide a more trail-smoothing feel. Some of this has to do with the increased air volume from the wider rims, plus the rim design is simply more compliant and forgiving than the stiffer models. While they are super lightweight and relatively stiff, they don't feel especially quick, we attribute this to the damped feel and slower freehub engagement.
The S35 Carbon Logo wheels lost a bit of ground to the competition for their sub-par freehub engagement. The freehub has 4-pawls that engage simultaneously on a 36-tooth drive ring giving them 10-degrees between engagement points. While 10-degrees is relatively standard, the new breed of faster-engaging hubs feels notably quicker and higher performance.
Ten-degree engagement, or worse, is what the majority of riders are probably already riding. We doubt most riders would notice the difference until you experience engagement that is significantly quicker. When riding these wheels back to back with wheels that have 3-degree and even 0.52-degree engagement, however, the difference is striking. It is worth noting that the S35 Carbon wheels can also be purchased with the Industry Nine Hydra hubs with 0.52-degree engagement, a $500 upgrade that we feel is worth every penny.
Ibis has created an impressively lightweight wheelset with their new S35 rims, and these are some of the lightest weight options in this test.
At just 1,744 grams for the pair in a 29" wheel size, these are just 31 grams heavier than the lightest models in the test and a fair amount lighter than most of the other competitors. Wheels this lightweight are almost certain to lighten up the overall weight of your bike and make those long climbs and big days in the saddle a little bit easier. Interestingly, the S35 wheels didn't provide as lively of a ride feel as the other lightest models, and we attribute this to the damped feel and somewhat lethargic 10-degree freehub engagement.
Our testers put the S35 Carbon wheels through the same level of abuse as all of the other models in this test. Like most modern carbon wheels, they are lightweight but they feel incredibly strong and can take a beating. We absolutely rimmed out the rear wheel on more than one occasion and thrashed out way down super rough and chunky trails. There are zero signs of damage and the wheels are as true as the day we got them. Ibis claims that the shorter BST bead-wall is less likely to break on hard impacts and that their Toughened Hybrid Carbon formula and design creates a bead-wall which is allowed to flex slightly during impact. Marketing speak aside, Ibis backs their carbon rims with a 7-year no-fault guarantee that includes "failure from impact during normal riding conditions". The Logo hubs are also covered with a 2-year warranty.
With a retail price of $1,299, we feel that the S35 Carbon Logo wheels are pretty good value. They are among the least expensive carbon models we've tested, only $100 more than out best buy award winner. We love the smooth, comfortable, damped ride feel of these wheels and the high level of traction that provide. Our main gripe is the 10-degree freehub engagement, and while it isn't terrible we hope for higher performance at this price point.
The Ibis S35 Carbon wheels are quality, lightweight and relatively affordable set of high-performance mountain bike wheels. Their ride quality was defined by their traction and comfortable balance of stiffness and compliance. We feel these are a great option for the trail and all-mountain rider who prioritizes weight, comfort, and traction. Riders seeking the ride quality of the S35 wheels with lightning quick freehub engagement would do well to consider spending a bit more money and getting these wheels with the Industry Nine Hydra hubs.
Other Versions and Accessories
Ibis makes a small line of alloy and carbon fiber rims and complete wheelsets for mountain biking. All of the carbon wheels can be purchased with Logo hubs as tested, or you can upgrade to the Industry Nine Hydra hubs for an additional $500. The Hydra hubs have outrageous 0.52-degree freehub engagement and are worth every penny. The S35 Carbon wheels are available in both 27.5" and 29" wheel sizes. Ibis also makes an aluminum version of the S35 with Logo hubs that retails for $499.
In addition to the S35, Ibis makes the S28 in both aluminum and carbon. The S28 rims have a narrower 28mm internal rim width and the carbon models can be purchased with either Logo or Hydra hubs.Both the S35 and S28 Carbon rims can be purchased as a rim only for $525 per rim. The aluminum rims are offered at $99 a piece.
— Jeremy Benson, Pat Donahue, Joshua Hutchens