Crankbrothers took a different route with their Synthesis carbon wheels by creating front- and rear-specific rims. There's a stiffer rim in the back to better handle bigger hits, while the front rim is supposed to be more compliant in order to provide extra traction and comfort.
The Synthesis wheel system comes in three different configurations - one for XC, one for all-mountain and enduro riding, and one for DH. We've had the middle sibling, the Synthesis E on test for a number of months now to see how they fare in varied riding conditions and to see if they actually do offer a benefit over a traditional wheelset.
There are also multiple hub choices. Our test wheels were laced up with Project 321 hubs, and
Synthesis E11 Wheels
• Intended use: Enduro/All-Mountain
• Carbon rim, front and rear-specific "tunes"
• 27.5" or 29" options
• Project 321 hubs, 2.5-degrees quiet engagement
• Designed to fail in a propagation mode
• Lifetime warranty on rims
• 1,825g (29" wheelset)
• $2,399 USD
• $699 USD (rim only)
the wheels are also offered with Industry Nine's 690-point-engagement Hydra System hubs. Synthesis wheels come with a lifetime warranty, which covers rims that break during normal riding conditions. In other words, leaving them behind your car and backing over them doesn't count.
Synthesis isn't the first to offer front- and rear-wheel-specific rims, but they have taken the concept to the next level.Construction
The Synthesis carbon wheels are designed to work as a system and are the creation of Jason Schiers and Mello Bouwmeester. Both of these guys have quite the background in the bike industry, which we went a little more in-depth on with our "First Look"
of the Synthesis wheels last year.
The concept of the wheels is that with more compliance the front wheel can more easily find its way, and then with more stiffness in the back wheel the bike will track well. This is similar to how most riders run a little less pressure in their front tire than the rear. If the front wheel is too stiff, it won't flex and hold the trail. Rather, it will skip around and ride poorly. Conversely, the rear wheel has to be stiff to manage larger hits and power through impacts with more force.
Safe Failure Mode
After a lot of prototypes and back-to-back testing of wheels, the team settled on what they felt was the ideal combination of the two: a more compliant front and stiffer rear wheel. The front wheel has a reduced spoke count, lighter gauge spokes, and lower spoke tension. The rim itself is slightly lighter and is slightly wider than the rear. This is to pair with running a slightly wider tire up front and allow the tire to have a rounder profile.
The rear wheel's higher spoke count, higher spoke tension, and narrower rim stiffens things up and sharpens up the tire's profile for cornering. The rim flanges are made thicker to handle higher impacts. Crankbrothers claim that this combination of rim design and wheel build creates a more durable yet compliant ride.
As everything can fail, Synthesis wheels are designed to fail in a manner that is controlled, rather than catastrophic. Schiers claims he has been obsessive about the way carbon fails and has worked hard to figure out how to manage catastrophic failure ever since he made the first Edge/Enve wheels years ago.
The ultra-thick carbon sections have some traits in them that can't be duplicated in traditional thin-wall tubular-section rim types. The resin system used in the carbon is a special high-impact formula and the layup schedule is tailored to disperse impacts. Some of the layups and materials are similar to those that protect F-1 drivers in race cars where safety is paramount.
The wheels are available with Project 321 (left) or Industry Nine's Hydra hubs (right).
Schiers says that if the Synthesis rims do fail it would be in a propagation type mode, with the damage spread across a wide area of the structure. Like the properties of an aluminum rim, the carbon is constructed to produce a noticeable deterioration - a heads up - that will hopefully catch the attention of its owner before further damage leads to a complete failure. Schiers believes that anyone who is developing carbon wheels has a responsibility to manage their failure modes to ensure a safe and controlled event.Performance
I've spent many hours on the Synthesis E wheels. They've been my go-to on the Yeti SB130 I've been using as a test sled. That means I've had plenty of opportunities to compare the E 11's to the alternative carbon and aluminum hoops that I've swapped off and on more times than I care to count.
I'm happy to report that I experienced no issues. The high engagement of the hubs was great, and the wheels delivered an excellent ride quality. I wasn't easy on them either. I thunder cased multiple rocks and ignored that I was running seriously low air pressure at times, yet I never flatted nor suffered
any damage to the wheels outside of the standard rock gouges that are unavoidable in North Carolina.
The telling moment came after I had switched out the Synthesis E 11 wheels with another carbon wheelset. Same bike, same trails, but a very
different ride experience. I was getting kicked around and couldn't seem to find the sweet spot on the SB130 anymore. Eventually, I did get my groove back with the other carbon wheels and didn't give it much thought - until I swapped back to the Synthesis. The difference in ride quality was noticeable.
The difference between the ride quality of the Synthesis wheels and their high-end competitors is quite remarkable. Upon riding these wheels, it's easier than ever to comprehend that there's a lot more to a wheel than it just being stiff and strong. Compliance and ride quality directly translate to comfort and control on the bike. Just like the difference in vibration damping an aluminum handlebar has vs a well made carbon bar, it's easy to feel the difference in the ride characteristics of the Synthesis wheels.
Compliant and comfortable ride+
High engagement hubs+
Benefits could be negated if not used in the full system