2021 Specialized Stumpjumper Drops Horst-Link, Dedicated 27.5 models

Specialized moves to a flexible stay suspension design for carbon models, and ditches 27.5-wheeled builds for the new Stumpjumper.
Photos: Specialized

With the release of the 2021 Stumpjumper Evo last week, Specialized signaled that it may have a revised, lesser-travel Stumpy on the way too. Today it’s here, and Specialized has done some interesting things with the remodel. To sum it up above ground, Specialized has switched the Stumpjumper to a Flexstay design, getting rid of the pivot found between the chain and seat stays (on the carbon models) and they have ditched dedicated 27.5-inch models, though the new Stumpy, like the Evo, is mullet-compatible.

This also means that Specialized doesn’t have any dedicated 27.5-wheeled full-suspension bikes anymore. They have the Fatboy, a 26-inch fatbike, the Pitch, an entry-level 26-inch hardtail, and the P3, a 26-inch dirt jumper. Somehow, 26ers have outlasted 27.5, at least for the Specialized lineup. This does leave one of their eMTBs though; the Turbo Kenevo is a 27.5+ eMTB. We won’t be surprised if that changes on the next round.

Let’s start with the frame. There are two options; carbon and aluminum. Specialized actually did keep the Horst Link on the aluminum frames, but carbon frames will get the Flexstay design. On the new carbon frames, Specialized says that they have shed 100g on the S4 size (large). They did this partly by ditching the rear pivots, and optimizing the carbon layup throughout the frame, optimizing stiffness, compliance, and weight in the right places.

Travel on the new Stumpy is 140/130mm in the front/rear. Overall, Specialized says they went with a pretty linear curve in the mid-travel bike to make sure there was as much usable travel as possible, however there is a sharp rise in the end stroke for less harsh bottom outs. “We wanted to bottom out, we just didn’t want to feel it,” said Specialized developers in a presentation about the bike.

To create an active-feeling suspension, Specialized went with a “very light” shock tune using Fox DPS shocks. Developers say not to expect a firm, platform feel, but it should create a lot of traction. Specialized says that this pumps in more low-speed compression without too much high-speed compression, and adds a natural preload. Users can add volume spacers if needed.

The SWAT box stuck around, and Specialized engineers expanded the room by about 20%. They kept touches like the raised rubber chain slap guard to keep things quiet, along with the protective downtube cover.

Specialized sought a way to convert the trail bike over to 29 entirely and they managed to pull it off, and with six sizes, S1-S6, which translates to XS-XXL. Sizing is based off of reach and wheelbase length, so riders can size up or down depending on how long they like their bike. Rather than choosing a bike based on inseam, buyers can choose a bike based on length.

With the new 29er sizing, the S1 has a better standover height than that of the previous 27.5 bike, which should reassure shorter riders. If folks want even more clearance for steeper terrain, they can swap out the rear wheel for a 27.5, obviously not included. Specialized say they were very confident in the move to bigger wheels. “We’ve always been about 29.”

On an S3, which translates to a size M, in the low position, the reach measures 450mm, the HTA is 65°, the BB height is 333mm (also across sizes except S1), with a 1200mm wheelbase, 744mm standover height, and a 76° STA. For a “medium,” the standover is not the lowest out there. The Stumpjumper uses a reduced 44mm offset fork.

Like the Stumpy Evo, the Stumpjumper’s geo is adjustable with a flip chip, changing the BB by 7mm and the HTA and STA by a half-degree.

Build kits for the bike make it a lighter-duty trail bike than the Evo, with inline Fox DPS shocks, and SRAM G2 brakes, rather than Codes, not to mention the lighter Flexstay instead of a Horst-link. “We want to keep it super durable and trail worthy.”

See the Specialized website for more information, build kits, and pricing.

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