Introducing the new Crankbrothers Synthesis carbon wheels

The all new Crankbrothers Synthesis wheelset launches today and promises good old fashioned Murican quality mixed with some left field thinking.

The wheels originally appeared at Eurobike, hidden away in a mysterious room that we had to swear an oath of secrecy just to enter. Fast forward a couple of months and they’re finally here for a review.

Flexy versus Stiffy

The new Crankbrothers Synthesis wheels try to address the old belief that alloy rims are too flexy for fast dudes and carbon rims are too stiff for everyone else. Crankbrothers apparently tested hundreds of different combinations of wheels, mixing up spoke tension, spoke counts and even carbon layups.

Crankbrothers told us that after hundreds of runs on hundreds of variations of wheels all of their test pilots reached the same conclusion. They all went for a combination of wheels that puts a more compliant wheel up front and a stiffer wheel out back.

The new wheels have been built with the help of Jason Schiers, Mello Bouwmeester and Unno DH team riders Greg Williamson and Taylor Vernon. You might find Jason’s name particularly interesting as one of the co-founders of Enve Wheels and a sworn champion of carbon hoops. We met Jason at Eurobike (hidden in that secret room with the wheels) and believe us when we say it, he is insanely passionate about carbon!

Crankbrothers are calling their new Synthesis wheels a ‘front and rear specific carbon wheel system’.

Business up front

According to CB, the front wheel is designed “to turn”. It’s tuned to be compliant and to absorb bumps from the trail whilst maintaining your wheel’s contact patch. The aim is to give you grip, control in the turns and confidence when you’re handling the bike.

How does that work? First up, CB have gone for a wider rim for the front wheel. That’s intended to give a wider and rounder tyre profile and a larger tyre volume for better control.

They’ve also made the front rim lighter than the rear, reduced the spoke count and used lighter weight spokes.

Party behind

CB have built their back wheel with a a narrower profile and beefier rim. It’s built tougher to take more of a hammering and to offer a firmer, stiffer ride. Where the front wheel is designed for better turning and compliance, the rear wheel is designed for better tracking and to take more abuse.

Crankbrothers have built the rear rim with a narrower profile than the front. That’s designed to offer better rolling resistance than a wider rim, to give a sharper tyre profile and to allow riders to run narrower tyres if they want to.

The rear wheel is built with heavier, tougher spokes and also uses more of them than the front wheel. The rim itself is also built with a carbon layup that is designed to be heavier and tougher than front.

Murican Hubs

Merida Big.Trailtea

The hard work doesn’t stop at the rims. Crankbrothers have teamed up with US hub manufacturer Project321, who build their hubs in Bend Oregon. The new CB Synthesis wheels come with the a choice of a Synthesis 11 hub or Synthesis E hub, both of which have US made Project321 built internals.

The Synthesis 11 hubs have 6 pawls, 144 points of engagement and are available with a ‘quiet or loud’ design. You get the quiet version as standard or you can upgrade afterwards to go noisy.

The Project 11 hubs use magnets instead of springs to move the pawls. That’s meant to reduce drag and noise. The design also makes the hub stronger under load which (you might need to read this a couple of times!) CB explain with: “The use of magnets in this configuration the pawl force against the drive ring is at its strongest when the pawl is fully engaged. As the pawl climbs the drive ring teeth during freewheeling the force (and friction) is reduced as the pawl magnets get farther away from the drive ring. This is the exact opposite of traditional mechanical push springs where the weakest point of the spring is at full engagement and the spring force gets stronger (creating more friction and drag) as the pawl is pushed up over the drive ring teeth during free wheeling“.

If you want to save some cash you can get the SynthesisE hubs which are 3 pawl with springs rather than the magnetic system.

and if you break ’em?

We’re looking forward to casing the living daylights out of a pair of Synthesis Wheels in the next couple of weeks. It’s good to know that CB offer lifetime crash replacement on rims if we or you do manage to kill any.


The Synthesis wheels will come in three options, with various choices of boost and non-boost and Shimano and SRAM drivers. They’re available in 27.5″ and 29″ and you can buy rims on their own or complete wheelsets.

Rims are a not inconsiderable €700 each. Wheelsets cost around €1700 with the E hubs or €2400 for the posher 11 hubs.

DH11 – for downhill

Synthesis E – for enduro

Synthesis XCT – XC and trail riding

We’ve got a pair of the new Synthesis rims here at Wideopen for a long term hammering.

We’ll report back when they’ve done some more laps!