Specialized Fuse and Ruze 27.5+ hardtails, and Rumor 650b

First look at new ‘6Fattie’ bikes and women's options

Industry support for 27.5+ (aka 27.5 Plus) has been the subject of gossip for some time now. The slimmed-down fat bike concept uses wide 650b rims (aka 27.5in) and 3.0in width tyres that fit within a wide-set 29er frame. Proving the concept has now moved well past an industry murmur, Specialized has announced its entry into the market with a range of men’s and women’s hardtails and tyres, dubbing the wheel size ‘6Fattie’


In addition to these fat-ish bikes and tyres, Specialized has released details of a smaller wheeled version of the Rumor, the Big Red S’s highly popular women’s XC/Trail bike – welcome, the Rumor 650b.

Fuse and Ruze introduce ‘6Fattie’

Fuse and Ruze are all-new men’s and women’s trail hardtails designed for 650bx3in tyres, something Specialized is calling ‘6Fattie’.

Compared with more cross country-orientated hardtails, these frames feature slacker trail geometry and slightly lengthened fork travel for more aggressive riding. The frames are made with butted ‘M4’ level aluminium, with smooth welds, internal cable routing and Boost 148mm dropouts.

The most unique aspect of these bikes is seen at the chain stays, the patented ‘diamond stays’ allow for insanely short 430mm tyres to clean the 3in width rubber :

‘Diamond Stay’ is how Specialized achieve 430mm length chainstays for a 3in-wide tyre

The most unique frame feature is the patented ‘Diamond Stay’ – a massively open and wide-set chainstay design that enables the 3in rear tyre to fit within the 430mm length ‘stays.

Although it’s unclear just what its comparisons are made against, Specialized claims that riders using 6Fatties at low pressures can expect a 69 percent increase in tyre contact patch. Additionally, it claims that a 56 percent increase in tyre volume makes for a far more comfortable and controlled ride.

The fuse (men’s) and ruze (women’s) trail hardtails introduce ‘6fattie’ wheels to specialized :

We suspect this is the Fuse Pro, although exact model details are to be confirmed

We’re told both the Fuse and Ruze will be available in Pro, Expert and Comp level options. Although exact details and prices are to be confirmed, we’ll update this story as we get them.

6Fattie Ground Control and Purgatory tyres

With the emergence of the Fuse and Ruze hardtails, Specialized is also introducing new tyres. Exact details for these new tyres are currently limited, but we can pull some assumptions based on previous models.

The Ground Control is a well-rounded trail option that’s commonly featured as a rear tyre on many of Specialized’s trail and enduro bikes. It’s likely that the 650bx3in version will be available in a ‘2Bliss’ option for tubeless compatibility.

The Purgatory is another popular trail model and is often seen on the front wheel of many Specialized’s more aggressive trail and enduro bikes. It’s a little slower rolling than the Ground Control, but it’s designed to bite hard in corners. Given a 650bx2.3in version weighs around 730g, we don’t expect the 3.0in version to be particularly light. 

With the investment in these new trail tyres, we wouldn’t be surprised if Specialized has something more coming to match other brand’s 27.5+ dual suspension bike offerings.

Rumor 650b

The rumor gets another option with the rumor 650b :

Joining the 29in wheeled option, Specialized will now offer a Rumor 650b (aka 27.5in)

As a women’s specific version of the Camber, the Rumor 29 has been a hugely popular XC/trail bike. Specialized is now adding further options with a longer travel, smaller wheeled 650b version, something that shorter or generally more aggressive riders are likely to be pleased to see.

The specialized rumor expert 650b features a rockshox pike 130mm fork, specialized command ir dropper post and sram 1×11 drivetrain : the specialized rumor expert 650b features a rockshox pike 130mm fork, specialized command ir dropper post and sram 1×11 drivetrain

Rumor Expert 650b, pricing and availability to be confirmed

The Rumor 650b will be offered in three levels; Rumor Expert 650b, Rumor Comp 650b and the Rumor 650b. All models feature the same brand-new butted M5 aluminium frame.

Built around Specialized’s ‘Women’s Trail Geometry’, there are three frame sizes available. The smallest has a miniscule claimed 695mm standover height and compact 544mm effective top tube length. The two larger sizes keep with respectively low standover heights.

Out back, the FSR suspension system delivers 125mm of rear wheel travel and is controlled by a ‘Women’s Custom Tune’ FOX Factory CTD (Climb, Trail, Descend) rear shock, with the base model featuring a shock from X-Fusion. All three models are matched with 130mm travel forks up front.

The new frame offers clean internal cable routing, including space for a stealth dropper seatpost (only specced on the Expert model).

Perhpas a little more agile through the turns, the rumor 650b should quickly find an eager market : perhpas a little more agile through the turns, the rumor 650b should quickly find an eager market

The Rumor 650b in use

“Women are getting after it and riding a variety of trails – our rider feedback reflected a desire to have the Rumor available in both 29 and 650b due to the vast array of trails women are riding, so we’re excited to add this bike to our trail family,” said Amy Nelson, the Specialized women’s mountain product manager.

Specialized claims that the Rumor 29 shines on open and rocky trails, while the Rumor 650b excels on tighter, twisty single-track.


All models will be equipped with 2.3in width Specialized Purgatory and Ground Control tyres front and rear respectively. Further aiding in traction and control are ultra-wide 29mm inner width rims on the Expert model and 26mm inner width on the base model. The middle Comp model comes with narrower 21mm rims, which are likely to be lighter in weight.