Crankbrothers have announced the addition of several new aluminum options to their Synthesis wheel lineup. Like their carbon counterparts, the aptly named Synthesis Alloy wheels feature a front wheel with a slightly wider rim that's said to be more compliant, which is paired with a stiffer rear wheel.
There are four different wheelsets in the lineup, with intended uses ranging from XC / trail riding to e-biking, but it's the Synthesis E wheelset that's reviewed here (E stands for Enduro), with Crankbrothers' branded hubs.
The front wheel is priced at $239, and the rear is $359 USD. There's also an Industry Nine 1/1 hub equipped version, which goes for $299 for the front wheel and $499 for the rear. The wheels are sold individually rather than in sets, which means you could choose to go with the fancier rear hub to get quicker engagement and still save a little money on the front hub.
Crankbrothers Synthesis E Alloy Details
• Intended use: enduro
• 29" and 27.5" options
• 6013 T6 aluminum rims
• 31.5mm inner rim width (f) / 29.5mm inner width (r)
• 32 Sapim Race spokes rear / 28 Sapim D-Light spokes front
• Engagement: 17º
• Boost spacing
• XD, Microspline, and HG freehub options
• Weight (29"): 2,072 grams, 939g front / 1133g rear
• Price: $598 USD; $239 front / $359 rear
On my scale the wheels weighed in at 939 grams for the front and 1133 for the rear, for a total weight of 2,072 grams for the set, including rim tape and valve stems.Details
Along with using two different rim widths (the front measures 31.5mm internally, and the rear measures 29.5mm) Crankbrothers also used different spoke counts and spoke thicknesses in order to achieve the ride characteristics they were looking for.
The front wheel is laced with 28 Sapim D-Light spokes, and the rear is laced with 32 Sapim Race spokes, which measure 1.8mm in the center vs. the D-Lights, which measure 1.6mm. The good news is that Crankbrothers didn't try and completely re-invent the wheel here – tried and true J-bend spokes are used, laced in a three-cross pattern.
The hub uses a three-pawl design that interfaces with a 21-tooth drive ring, creating 17-degrees between engagement points. The Industry Nine option uses a six pawl driver and 45 tooth drive ring that results in 4° between engagement points.
The rear hub uses a three pawl design and ratchets on a 21-tooth drive ring. Ride Impressions
I've had two different sets of tires on the Synthesis E Alloy wheels so far, and both seated and sealed without any issues. These wheels saw action on a couple different test bikes, but the bulk of the testing took place with them installed on a Norco Optic. I typically run a 2.5" front tire and a 2.4" rear tire, a setup that worked especially well with the Synthesis E wheels. The concept of having two different different rim widths isn't new, but it does make a lot of sense. The wider front rim helps support the wider tire, while the rear rim width works well with the slightly narrower tread profile. Running two tires with the same width works just fine as well - remember, we're still only talking about a 2mm difference in inner width dimensions here.
The wheels felt solid and comfortable, although when it comes to judging compliance I'd be hard pressed to name an aluminum wheelset that I've ridden in the last couple of years that felt too
stiff. Now, I could rattle off the names of carbon wheelsets that were on the harsher side of the scale, but with aluminum that harshness isn't nearly as common. Still, the Synthesis wheels didn't give me any reason to complain as far as overall ride feel goes, no matter if I was plowing through a jumble of roots or trying to see how fast I could blast through a berm. They're nice and quiet, too; the freehub emits only a subtle clicking sound when coasting, and there weren't any distracting spoke pings or twangs to be heard.
The only issue I ran into was my own fault – a mis-judged bunnyhop during a night ride caused me to smack the rear wheel into a square edged rock as hard as possible at full speed. That resulted in a dent and a flat spot one one side of the rim, but the tire stayed on and I didn't lose any air. I've since straightened the dent out as much as possible, and the wheel's still going strong.
When I pulled the freehub body off the Crankbrothers hub I found that some moisture had made its way in, sneaking past the rubber seal the sits between the freehub body and the hub shell. There wasn't any rust, and the cartridge bearings themselves were all spinning smoothly, but it's worth a mention. Of course, I live in a very, very wet part of the world, especially this time of the year – riders in drier climates likely wouldn't have anything to worry about.
Speaking of hubs, the 17-degrees between engagement points on the Crankbrothers hub isn't the fastest out there; riders who place a high priority on have ultra-quick engaging hubs would be better served by going with the Industry Nine option. Personally, the slower engagement didn't bother me once I was out on a ride, but I did notice it when switching to a wheelset with faster engagement.
Comfortable ride feel+
Proven design: J-bend spokes, 3-cross pattern
Not the fastest engaging rear hub