The Synthesis wheels from Crankbrothers have been around a while, with a range that’s grown to accommodate all tastes of rider, including e-MTB.
The Synthesis XCT 11 are Crankbrothers’ top–end carbon wheelset, aimed firmly at XC/trail use. Downhill and enduro versions in the Synthesis 11 line-up are available for more burly action and rim only options too – if you prefer to build your own wheels. Drop the ’11’ and you’ll still get the same XCT carbon rims but with a standard Synthesis hub and round spokes. For those with slightly lighter wallets, there are alloy versions too.
Crankbrothers’ unique tuned carbon wheels system uses front and rear rim specific sizing, for compliance and control up front, and stiffness at the rear for maximum output. Industry Nine Hydra hubs laced with Sapim CX-Ray spokes round out a sleek-looking but pricey package.
If you’re in the market for a high-end and expensive set of wheels, then it's good to know that the rims come with a lifetime warranty which will give you peace of mind if you like to push it hard.
Design and specifications
As you would expect for the price tag, the XCT 11s come with a big box of bells and whistles. Ready to roll with a pre-installed rim strip, you’ll just need to add tubeless valves of your choice.
Weighing in at 1,560g for the set, they’re in the featherweight category and certainly on par with other XC-oriented carbon wheels out there.
The rim profile is relatively low at 19mm for both wheels, but that’s where the similarities end. Front and rear-specific rims give each wheel their own ride feel and are optimized for efficiency. The carbon layup is also different, with the front rim offering up a higher level of compliance.
Up front, the outer rim measures 31.1mm with an internal width of 26.5mm. Laced with 28 of Sapim’s finest bladed CX–Ray spokes with a lighter tensioning than the rear and in a lighter gauge. Whilst at the rear, the outer rim drops a little to 29.5mm with an internal width of 24.5mm and is laced with 32 spokes and a tighter tune.
At the heart of the wheelset you’ll find Industry Nine Hydra hubs. My rear wheel came with a XD/Boost freehub, but Micro Spline and HG are also available and easily interchangeable.
Performance
I’ve been riding these wheels for two years on a variety of trails, through all seasons and have really put them through the grinder. I ride hard and enjoy pushing short travel bikes beyond their comfort zone. I’m talking downcountry here, 120-130mm aggressive geo trail rippers – and the XCTs have proven to be a perfect pairing for them.
Set-up was easy, seating the tires caused no drama and inflation was hassle-free, with a good tubeless pump. All tires tested were 29 x 2.4, I settled on a Maxxis Dissector up front and a Maxxis Rekon out back - my absolute favorite downcountry setup for speed and grip.
Like most carbon wheels, there’s increased stiffness that transfers into snappy and direct handling, but where these wheels excel is in the unique tuning and the different spoke count front and rear. At the front, the wider rim rounds out the tire a little and seemed to increase grip on offer to laughable levels, which of course, transfers into buckets of confidence. The front end tracks the trail so well that I found myself holding some wild lines with more composure than I was expecting. There’s a great balance of stiffness for accuracy, coupled with that softer compliance built into the rim and spoke tune, giving a lively but composed feel which makes you want to pop and play all over the trail.
But the party’s not all at the front. The stiffer, narrower rear rim and higher tighter tuned spoke count boosts power transfer, which feels snappy out of corners. The tracking is great too, especially at speed across technical roots and rock sections. The narrower rim reduces rolling resistance a bit, especially when using a lower-profile tire for speed. The immediate and impressive pickup from the I9 Hydra hubs is awesome, power from the pedals is delivered with near instant effect, especially noticeable on technical climbs – and that sound…
After more miles than I can remember, and riding them hard, I’ve had absolutely no issues with them – which is a good job considering the price tag – but the lifetime warranty on these rims does help to negate the cost a little.
Verdict
OK, so the Synthesis XCT 11 29 Carbons are expensive. But what you get for your money are some killer-looking and high-performing rims, laced with top-end Sapim-bladed CX-Ray spokes built around Industry Nine Hydra hubs. A cracking package with a lifetime guarantee on the rims.
They meld oodles of control and compliancy into a superbly balanced tough and snappy set of wheels that may just up your game and push you harder. If you want to go all XC, wrap them in some race rubber for a truly fast and responsive ride or go burly, with bigger rubber and push your limits.
If you’re riding more challenging terrain then you could opt for the DH or enduro versions. And if the eye watering cost is an issue, you could opt for the standard XCTs to soften the blow – a little!
| Attributes | Notes | Rating |
|---|---|---|
| Ride feel | Carbon accuracy with trail taming compliance | ★★★★★ |
| Power transfer | Super rapid engagement from the i9 hubs | ★★★★ |
| Durability | Bullet-proof after a lot of hard riding | ★★★★★ |
| Value for money | Expensive, but worth the investment | ★★★★ |
Tech specs: Crankbrothers Synthesis XCT 11 29 wheelset
- Price: $2,400.00 / £2,250.00 / €2,400.00
- Options: XCT 11 29in / Enduro 11 29in, 27.5in / DH 11 29in, 27.5in
- Freehub options: SRAM XD / Shimano HG / Shimano Micro Spline
- Hub engagement: 0.52-degree Quick Engagement / six pawls
- Rim height: 19mm
- Inner rim width: 26.5mm (f) 24.5mm (r)
- Outer Rim width: 31.1mm (f) 29.5 (r)
- Spokes: Sapim CX-Ray
- Spoke count: 28 (f) 32 (r)
- Compatibility: Tubeless ready
- Weight: 1,519g per pair (XCT 11 29in tested)
