Specialized are the latest entrant into the growing market of wide-bodied carbon wheels, rolling a set of the new Roval Traverse SL Fattie wheels Flow’s way last week. These extra fat hoops are available in 29 and 27.5″ – we’ve got the smaller size on hard for review.

When it comes to ‘in-house’ wheels, Specialized’s Roval wheel line up is really leading the way (along with Bontrager, who also have a seriously impressive range of in-house wheels for Trek), especially with regard to carbon mountain bike wheels. We’ve had very pleasant experiences with Roval wheels in the past, including the Roval Control 29 Carbon wheels. These new Fatties are the A380 of the Roval range – the biggest, baddest and widest hoops in the line-up, with an internal width of 30mm.
Why so wide? The concept of a wide rim has been growing in popularity steadily over the past few years (in mountain biking and road riding too). A wider rim offers more support to the tyre, allowing lower pressure and consequently more traction, with less of the negative effects of tyre roll that you’d encounter with a narrower rim. Here at Flow we’re also currently testing the Ibis 741 rims, which take this concept even further than the Rovals, with an internal width of 35mm.

It goes without saying that the Traverse SL Fattie wheels are meant for aggressive riding and big rubber – they’re standard fare on Specialized’s S-Works Enduro models for 2015. Even still, the weight of these things is incredibly impressive. Our set, configured with a Shimano freehub body, valve stems and rim tape, weighs in at just 1571g!

Taking a quick look at the other stand out features, the Fatties use a hookless bead construction (the rim does not have a traditional bead hook) which makes for a more impact resistant profile and also gives the tyre more volume. The freehub mechanism uses DT’s Star Ratchet system, while the front hub can be configured for 15mm or 20mm axles. Colour matchers out there will rejoice that the rims are supplied with three different sets of decals, so you can pimp your ride. Of course these wheels are also ready for tubeless use, fitted with a simple tape system to seal up the rim bed. 
 
As well as coming a 29″ variant, the Fatties are also available in an lower-priced alloy version too which come in at around 160g heavier for the set. We’ll be fitting these rims to a variety of bikes in the coming weeks. We’ve also got a set of the new 27.5″ Specialized Purgatory tyres for review too, so we’ll be wrapping these hoops in Specialized rubber as well.