The Crankbrothers Synthesis wheelset, with its front and rear wheel specific tune, has until now, only been offered in carbon. Now, there’s a new Synthesis Alloy Wheel Range, offering the same compliant front wheel, and stiff rear wheel, characteristics of the Synthesis Carbon but in aluminum. For those who prefer the material’s ride feel, it also brings the price down to something considerably more affordable. The Crankbrothers Synthesis Alloy wheelsets are available in XC, Enduro, and E-bike formats, all delivering the same Synthesis concept of two wheels specifically tuned for two different jobs. Here’s the details…

Rolling with different roles

Synthesis_Alloy_rimsThe Crankbrothers’ Synthesis wheelsets are the result of long and heated discussions between Jason Schiers, the original founder of ENVE, now Director of Product Development at Crankbrothers, and Mello Bouwmeester, Crankbrothers’ head composites engineer. Jason has been a long time proponent of stiff wheels, recognizing the performance gains attainable with wheels that are laterally very stiff, offering better tracking at speed, and instantaneous translation of power through the pedals into propulsion down the trail, realized with greater speed out of corners, making the rider faster. Jason’s philosophy and wheel designs earned him a reputation in the industry as the man who builds the strongest mountain bike wheels on the market.

At the other side of the argument was Mello Bouwmeester, who recognized the merits of more compliant wheels that provide a little dampening, reducing trail chatter, maintaining a more consistent contact patch with the terrain, translating to more grip, and improved handling and ride quality.

Crankbrothers Synthesis carbon wheelset- enduro rim cutaways

Front and rear rims of the Crankbrothers Synthesis Carbon wheelset, reviewed here.

It would be very easy to be convinced by either argument, if you were to hear them in isolation of one another. In developing the Synthesis wheels, Crankbrothers began by creating wheels of differing stiffness, and sending out different front and rear wheel combinations to test riders, to learn what level of stiffness was optimal for mountain biking. The optimal wheelset, as determined by the riders, was a combination of a very stiff rear wheel, and a compliant front wheel. Thus, the Synthesis was born.


It doesn’t take much to see the logic in a mix-and-match approach. Despite performing the same rolling role, the front and rear wheels also perform two distinct roles. For a start, the front wheel actually does the turning, while the rear wheel remains at a fixed angle within the frame, thus is subjected to far greater lateral forces. It also experiences greater loads. As riders, we often lighten the front wheel over rooty or rocky sections of trail, but we don’t always have the opportunity (or ability) to bunny hop these same sections, thus the rear wheel most often smashes into features. It must either be strong enough to deal with these square-edged hits, or else take on the form of a Pringle. Thus, arguments for a laterally stiff and strong rear wheel are easily won.


The front wheel must of course also be strong, and resist the temptation to bend under load, but it doesn’t experience quite the same lateral forces as the rear. We use the front wheel to turn and select lines through sections of technical trails. A more compliant wheel, offering some degree of forgiveness when your line choice is less than optimal, makes more sense at the front end of the bike. There’s nothing worse than that feeling of rolling the dice when you’re getting pinged about through a rough rock garden.

Crankbrothers Synthesis Alloy Wheelset details


Crankbrothers reckon they’ve distilled the perfect combination of stiffness and compliance into one wheelset, with specifically tuned front and rear wheels. They’ve done this by using differing numbers of spokes front and back, and by using different internal rim widths. Up front, the hub is laced to a wider aluminium rim by 28 spokes. Out back, the Boost freehub is laced to a narrower rim via 32 spokes. Disparity in rim internal widths will allow riders to run tyres with a broader profile up front, for an increased contact patch, and a narrower, more rounded tyre profile in the rear to bite into the trail. Spoke thickness varies, too – lighter up front than out back, and the tension of those spokes is greater in the rear.


Crankbrothers Synthesis Alloy Enduro Wheelset with i9 1/1 hubs

Crankbrothers are offering the Synthesis concept in three different alloy wheelsets; XCT, Enduro and E-Bike. The only category missing is Downhill, but they do have a Carbon Synthesis DH model. The range includes two hub options – Crankbrothers’ own hub design, providing 17º of engagement, and Industry Nine’s 1/1 hub, offering 4º of engagement, though you’re limited to the Crankbrothers hub only for the E-MTB wheelset.


“It was great to bring the ideas and concepts of the Carbon Synthesis product to a more affordable price point, giving everyone an opportunity to experience a tuned wheel system. Those that ride our new Alloy Synthesis wheel sets will get a taste of the improved riding sensations of which our flagship product is becoming known for,” said Jason Schiers, Director of Product Development, Crankbrothers.

Now, let’s take a look at the three shiny new wheelsets…

Synthesis Alloy XCT Wheels


Made for cross-country and trail riding, the new Crankbrothers Synthesis Alloy XCT wheelset is designed for “precise handling at full speed”. Available only in 29″, the stiff XCT rear wheel rim has a narrow internal width of 24.5mm laced with 32 spokes.


To maintain that stiffness and compliance contrast between the front and rear, the Synthesis XCT front wheel has just 28 spokes pulling on a rim with an inner width of 26.5mm. Being an XC race wheelset, both front and rear share the same Sapim D-Light spokes.


Built up to an 19 1/1 hub, the Synthesis Alloy XCT rear wheel is priced at $499

With Crankbrothers’ own hub, the front XCT Alloy wheel weighs a claimed 841g. The rear wheel with selection of XD, HG or Microspline driver, weighs a claimed 998g. Prices are $239 and $359, respectively.

Synthesis Alloy Enduro Wheels


The Crankbrothers Synthesis Alloy Enduro Wheelset is available in both 27.5″ and 29″ wheel sizes. The front wheel features an internal rim width of 31.5mm and is built up with 28 Sapim D-Light spokes. The rear wheel offers a narrower rim profile at an internal width of 29.5mm, built up to the hub with 32 heavier duty Sapim Race spokes for added stiffness.


With Crankbrothers’ own hub, the 27.5″ rear wheel weighs a claimed 1062g, while the 29er is a little heavier at 1095g. Both will set you back $359. The front wheel weighs a claimed 877g in 27.5″, and 902g in 29″. Both are priced at $239.

The E-MTB Ones


The Crankbrothers Synthesis Alloy E-Bike Wheelset is available in both 27.5″, 27.5″+ and 29″ wheel sizes. Internal rim widths are 31.55mm front and rear for the 27.5″ and 29″ rims, while they are considerably wider at 35.5mm front and rear for the 27.5″+ wheelset. 28 Sapim E-Light spokes pull on the front wheel rim, while 32 Sapim STRONG spokes pull on the rear wheel rim.


Built up to Crankbrothers’ own hubs, the Synthesis Alloy E-MTB 29er wheels weigh a claimed 980g and 1328g, front and rear, respectively. The 27.5″ wheels weigh in at 915g and 1174g, respectively, and the 27.5″+ wheels weigh 928g and 1181g, respectively. All will set you back $259 and $389, front and rear.

Pricing and Availability


The front and rear wheels of the Crankbrothers Synthesis Alloy Range are sold separately, allowing riders to take mixing and matching to another level, if they so wish. Want to run an E-Bike rear wheel with an Enduro front wheel for added robustness? Crack on. Or rather, roll on. The Crankbrothers Synthesis Alloy Range is offered with three freehub standards; XD, HG and Shimano’s new(ish) Microspline (HG). To upgrade the hub from Crankbrothers own to Industry Nine’s 1/1 hub (reviewed here) add $70 to the price of a front wheel, and $140 to the price of a rear. The full range is available now, direct from Crankbrothers.







  1. Mark on

    I guess I haven’t been paying attention, but how common is it now for alloy rims not to be drilled all the way through? Common enough for it not to be worth mentioning in a review.

  2. sjacobthewriter on

    Its nice to see these in Alloy. I know that Carbon Wheel Sets are all the rage, but I am just not sold on the durability, and for the price if your not a pro/sponsored rider it’s hard to justify sinking that kind of dough into something that can be so easily cracked.

        • K-Pop is dangerous to your health on

          This post is about wheels, but carbon frames can be repaired as well, and for years now. Again, you’re thinking in terms of the past. Propagating scare stories about carbon these days is awfully… gauche. Do you have anymore straws you’d like to grasp at?

            • K-Pop is dangerous to your health on

              Nope, common sense sent me. If you’re going to make claims it’s highly recommended that you catch up to the same decade we’re in, and at least keep your story straight when trying to make a point. But by all means carry on, this downward spiral of misinformation you’ve created is an easy target.

          • whatever on

            If he is propagating a scare story about carbon failure, then so are you with a scare story of denting a alloy wheels and alloy wheel failure. If your point is valid, then so is the counter point. It goes both ways.

            • K-Pop is dangerous to your health on

              The counter point was valid over a decade ago. Somebody isn’t listening. Drive by scolding doesn’t do much for the conversation if you fail to adhere to facts. Carbon is stronger than aluminum, this is fact. But whatever you need to tell yourself to get though the day is alright by me.

  3. Soloman on

    While Kpop’s role is usually one of a snobby devils advocate, I gotta agree with’em here. While aluminum rims are perfectly fine, carbon rims/parts are pretty darn equal if not superior to aluminum now a days.
    …Although… you could argue that you could buy 3 or 4 aluminum rims for the cost of 1 carbon rim…

  4. K-Pop is dangerous to your health on

    Maybe I should have kept the parameters to pro athletes who actually have to climb hills too, not just take shuttles or chairlifts to the top. Hey, with all that money you saved sticking with cheap aluminum wheels you can now afford helicopter trips to the top of the mountain. Yay!

  5. Shaun Davidge on

    I’m an amateur slightly overweight old rider who got carbon wheels on a Giant Anthem, 4 years ago. Wow! Never going back as far as I’m concerned. Cost more, sure. Break? Never heard of it in my circle of friends.


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