Unreleased alloy Specialized Stumpjumper teased in Fox’s Transfer Neo press material marks the brand’s return to cable drivetrains

By Tom Law

Published: Wednesday, 21 August 2024 at 14:41 PM


Press photos of Fox’s latest Transfer Neo wireless dropper post tease an unreleased aluminium version of Specialized’s latest Stumpjumper 15.

The Stumpjumper 15 was released last month, and costs up to £9,000 / $12,000. But if the alloy version comes to market soon, it will bring Specialized’s redesigned stalwart down to lower price points. 

The new trail bike also appears to support wired drivertrains, whereas the Stumpjumper 15 is wireless-only.

In another tease, Fox’s prototype electronic coil rear shock also appears in the photos. 

Cables return

The Stumpjumper name is visible on the seat tube.

Hidden in plain sight in Fox’s photos and video, Specialized and Fox ambassdor Matt Hunter can be seen riding what appears to be the as-yet unreleased aluminium Stumpjumper. 

The Stumpjumper name is visible on the seat tube and the frame’s lines are very similar to the carbon Stumpjumper 15. 

This unreleased bike is also missing the sidearm strut, which is a clue to it being a new Stumpjumper 15. 

But visible welds indicate a fully aluminium construction.

That will come as great news to some. The cheapest Stumpjumper 15 is still a heady £5,250 / $5,500 / €6,500. It’s also hardly unexpected. Specialized has had alloy and carbon versions of many of its bikes for years. 

However, Specialized typically launches its carbon and alloy bikes at the same time. 

It’s not unheard of for the brand to offer carbon-only options though. The current-generation Enduro is and has only been available with a carbon frame since its launch in 2019.

The leaked bike appears to be a fully aluminium construction.

What is of even greater intrigue is the apparent return of cable drivetrain compatibility. The carbon Stumpjumper 15 can only be used with wireless drivetrains, because there is no provision in the frame for a gear cable. Instead, its internal routing only caters for a dropper cable and brake hose. 

While SRAM’s wireless AXS Transmission drivetrains are becoming increasingly popular, this wireless-only feature could be a turn-off. For now, it effectively makes the Stumpjumper 15 only compatible with SRAM. 

Santa Cruz’s recently revised Bronson possibly shows a glimpse of Specialized’s thinking. Its more expensive CC frames are wireless-drivetrain only, while the cheaper C frames feature routing for cable drivetrains. 

If we had to guess, it may be that the Stumpjumper, and future Specialized mountain bikes, will feature wireless-only drivetrain compatibility on carbon models. Meanwhile, the option will be there for cable drivetrains on cheaper alloy equivalents. 

The same, but different

Specialized Stumpjumper
The new Stumpjumper appears to support wired drivetrains. – Fox

While hard to tell from the images and video provided by Fox, we presume this new bike shares the same geometry adjustments.  

You can see flip chips for adjusting the chainstay length and wheel size at the rear axle. Hunter appears to be running the bike in the longer of the two settings. While it’s hard to be sure, it also looks to be a mullet setup with a smaller 27.5-inch rear wheel. 

Judging by the size of the head tube, it also looks to use the same angle adjustable headset cups as its carbon sibling. 

Elsewhere, the down tube features Speciaized’s SWAT storage. Surprisingly, we think it’s using the brand’s older SWAT hatch, rather than the newer SWAT 4.0. 

If this is a prototype, we may see Specialized move to the newer design for production. 

A prototype electronic shock from Fox

Specialized Stumpjumper
Alongside the Stumpjumper name, Fox’s prototype electronic coil shock makes an appearance. – Fox

Sneaking into view in some of the images is Fox’s prototype electronic coil shock. This looks to share the same battery as the Transfer Neo dropper post, judging by the shape and size. 

You can also spot sensors mounted to both brake calipers. Whether the shock and seatpost can be synced together to influence suspension performance remains to be seen.

It also leaves the question of whether the alloy version of the Stumpjumper will come with the new Genie shock unanswered. First seen on the carbon Stumpjumper 15, the Genie was co-developed with Fox.