Raymon Korak

The Comp is the entry-level model in the range and, compared to the Pro, omits features only in the suspension, gears and brakes, not in the drivetrain. At the front is an SR Suntour XCR36X R air suspension fork with 140 mm of travel, while the rear features an SR Suntour EdgeX R air shock with a 205x60 mm mounting size. Braking is provided by Tektro Gemini SL four-piston brakes, which have plenty of reserve power on long descents even with the rider and luggage. The Bosch Purion 200 serves as the display.

The gears are particularly interesting: Shimano CUES uses Linkglide technology with thicker, flatter-profiled teeth on the cassette. Shimano states that this offers significantly higher wear resistance compared to conventional Hyperglide cassettes. On an e-MTB, where the motor applies additional torque to the chain with every gear change, this pays off: longer cassette service intervals and less readjustment. Ten gears with 11–48T cover even steep ramps thanks to motor assistance. The range advantage of the 12-speed groupset only becomes apparent when you want to conserve the battery and climb at a low cadence in Eco mode.

In the Pro, the added value lies almost entirely in the suspension and braking system. The RockShox Psylo Silver RC with 140 mm of travel and external compression and rebound adjustment responds more sensitively in the first third of its travel than the Suntour fork on the Comp, which noticeably improves traction and steering precision on rooty sections. At the rear is a RockShox Deluxe Select air shock, which harmonizes well with the drivetrain-neutral rear triangle and exhibits little pedal bob when walking.

Added to this is the Shimano Deore 12-speed with a 10–51T cassette, which offers one more finely graded gear on steep ramps than the 10-speed group. The Magura Luise Elite with four pistons requires less hand force than the Tektro system, which makes a difference on long descents. The Bosch Purion 400 is mounted on the handlebars. At 25.7 kg, the Pro weighs around 300 grams less than the Comp. For riders who move their Korak off-road several times a week, the Pro is the more balanced version.

In both Korak models, the fifth-generation Bosch Performance Line CX (BDU38) operates within the Bosch Smart System. The nominal power is 250 W, with peak power of 750 W. The control unit varies depending on the model: the Korak Comp uses the Bosch Purion 200, while the Korak Pro uses the Bosch Purion 400. Riding modes and settings are managed via the Bosch eBike Flow app.

In practice, two situations are crucial. If you have a long, consistently steep gravel climb ahead of you, constant power over time is what matters most: here, Turbo mode provides full assistance continuously but consumes the most energy. On the other hand, if you are riding a technical trail section with drops, switchbacks, and varying cadence, eMTB mode is the better choice. It automatically adjusts the assistance up and down based on pedal pressure, so you are less likely to spin out the rear wheel during sudden peaks in load.

The Korak comes pre-equipped for the Bosch Performance Upgrade 2.0. It is unlocked as software via the eBike Flow app and increases the maximum torque to up to 120 Nm, as well as the maximum assistance to up to 600 percent of your own pedaling power. You can then adjust the riding modes in the app using sliders, for example, towards more acceleration or a more economical setup.

Compared to the fourth generation, the noise level is particularly noticeable in everyday use. Bosch has eliminated the rattling of the freehub when struck off-road, and the motor runs more quietly under load. The higher-resolution torque and cadence sensors also ensure that the assistance engages more smoothly on slippery surfaces.

140 mm front and rear on 29-inch wheels is the classic all-mountain setup. The rear suspension is neutrally tuned to pedaling and is highly sensitive, while the large wheel diameter rolls over roots and steps more easily than 27.5 inches. This defines clear limits of use:

• Gravel paths and forest roads: significantly more comfort than a hardtail; on long climbs, it is worth closing the compression damping or using the lockout.
• Flow trails with berms and flat jumps: the Korak's preferred terrain, with the suspension travel remaining within its operating range during landings.
• Technical singletrack trails of difficulty S0 to S2: manageable, with the Pro benefiting especially from the RockShox suspension and more powerful Magura brakes.
• Bike parks, large drops, and continuous downhill riding: not intended. It lacks the suspension travel, tire volume, and suspension reserves for this.

The tires support this setup. The Korak Comp rolls on a 2.40-inch Schwalbe Nobby Nic, while the Pro uses a 2.35-inch Schwalbe Hans Dampf. If you mainly ride tours with a high proportion of asphalt and gravel, the Nobby Nic is the more efficient choice. If you prioritize descents, the Hans Dampf is the more suitable tread, and it can also be fitted to the Comp.