A real bargain from Specialized: The Stumpjumper 15 Alloy Comp offers excellent value for money!

Conclusion by Max Fuchs, BIKE test editor

With the Stumpjumper 15 Comp Alloy, Specialised has put together a well-rounded package for ambitious trail cyclists. Although the high-quality aluminium frame is on the heavy side, it incorporates almost all the technical features of its carbon counterpart. The sophisticated suspension, versatile geometry and solid spec appeal to riders who want reliable trail performance without having to pay the premium for the carbon models. In the mid-range category in particular, the Comp Alloy is therefore one of the most exciting all-mountain bikes of the season. If you shop around, you can currently find online models reduced to under 3,000 euros.

Key facts

• Price: approx. 4,500 euros
• Weight: 16.7 kg in size XL
• Frame: Specialized M5 Premium Alloy
• Suspension travel: 150 mm at the front / 145 mm at the rear
• Impeller size: 29 inches
• Chassis: FOX 36 Rhythm & FOX Float Performance GENIE
• Circuit: Shimano SLX 12-speed
• Brakes: TRP Trail EVO
• Area of application: Trail, All-Mountain

Aluminium instead of carbon – where Specialized cuts costs

The Comp Alloy is the entry-level model in the Stumpjumper 15 range. Compared with the carbon models, a high-quality M5 aluminium frame replaces the FACT carbon chassis. However, the basic design remains virtually unchanged. The rear suspension kinematics, geometry and adjustment options are taken directly from the higher-priced models.

The change in material naturally adds a little extra weight. However, the purchase price is significantly lower. Those who aren’t so concerned about saving every gram will get almost the same platform at a more attractive price. Even the well-known SWAT storage compartment is a feature the Comp Alloy has inherited from its carbon counterparts.

GENIE suspension is designed to combine comfort and performance

At the heart of the Stumpjumper range is the GENIE rear shock, developed in collaboration with FOX. Unlike traditional air shocks, the system uses two air chambers that specifically influence the suspension characteristics. Specialized promises a particularly sensitive response at the start of the travel, plenty of support in the mid-range and significantly higher end-stroke progression just before bottoming out. This is designed to allow the rear wheel to absorb small bumps smoothly, whilst also offering sufficient reserves for hard landings.

The Comp Alloy is fitted with a FOX Float Performance GENIE shock, paired with a FOX 36 Rhythm suspension fork at the front. Although the Rhythm version does do away with some adjustment options and the high-quality Kashima coating found on the top-of-the-range models, we have always found it to be a robust and functional trail fork.

Modern trail geometry with plenty of clearance

When it comes to the frame, Specialized has opted for a highly versatile design. The geometry can be adjusted at several points to suit different riding styles and terrain. The head angle can be adjusted using different headset cups. In addition, the Horst-Link bearings feature a flip chip to fine-tune the chainstay length and bottom bracket height. This allows riders to tune the bike for either a smoother ride or greater agility.

Solid features with no major weaknesses

When it comes to components, Specialized opts for tried-and-tested mid-range options rather than spectacular highlights. The Shimano SLX groupset has always been one of the most reliable drivetrains in this segment. Precise gear changes, high durability and affordable spare parts are clear selling points for the Japanese groupset. TRP Trail EVO four-piston brakes are used for stopping power. These powerful brakes complement the bike’s rugged build well and promise ample stopping power on long descents. Sturdy Roval Traverse aluminium wheels and high-grip Specialized tyres round off the package perfectly.

At home between tours and trails

With 145 millimetres of rear suspension travel and 150 millimetres at the front, Specialized has positioned the Stumpjumper almost perfectly within the trail/all-mountain segment. Its range of uses is correspondingly broad. Whether it’s an after-work ride, long tours in the Alps or technically demanding singletrack – the design is aimed at riders looking for just one bike to cover as many riding scenarios as possible. That said, in every scenario you’ll need to take it a bit easier on the climbs and on the flat. That’s because this bike, weighing almost 17 kilos, doesn’t have a particularly strong forward momentum. For those who prefer a more downhill-oriented ride, Specialized offers the upgraded EVO models in its range. With more suspension travel and more robust components, they’re specifically designed for enduro riders.

Who is the Stumpjumper 15 Comp Alloy suitable for?

The Comp Alloy is aimed at ambitious trail cyclists who are looking for modern suspension technology and strong downhill performance combined with all-round potential, but who deliberately opt for aluminium as their frame material and aren’t too concerned about the overall weight. Anyone who regularly tackles challenging rides and loves technical trails will find this a compelling and, at present, very good-value package. Those who prefer a lighter bike will find the carbon versions a more suitable alternative.

Pros and cons of the Specialized Stumpjumper Alloy Comp

Plus

• A trail all-rounder with plenty of downhill potential
• modern, adjustable geometry offering a high level of safety on descents
• The GENIE chassis combines responsiveness and performance reserves
• High-quality specification featuring FOX suspension and a Shimano SLX drivetrain
• good value for money compared with the carbon models

Minus

• heavier than the carbon versions
• fewer suspension adjustment options than on the top-of-the-range models
• Standard equipment prioritises functionality over premium features