Oso S 2025

The Ibis Oso S 2025 is the shortest-travel, XC-leaning member of Ibis's Oso family, a carbon down-country eMTB built around the Bosch Performance Line CX Gen 5 motor and a 600 Wh battery. Headline numbers: 140 mm of fork travel, 130 mm at the rear, 120 Nm of peak torque from the latest CX, a 63.9 to 64.7 degree head angle (size-tuned), reach stepping from 445 mm on S to 536 mm on XL across five sizes. The community framing is light but enthusiastic: @Brawwp highlights the bike's class-leading low standover height as a real differentiator, allowing flat-foot standing over the downtube even on the Small frame.

Drive system and range. Bosch Performance Line CX Gen 5 brings 120 Nm of peak torque, 250 W nominal, a manufacturer-claimed 750 W peak and a 2.8 kg motor weight. This is currently the most refined mid-drive in the eMTB market, with the deepest dealer-service network and the smoothest 100 to 120 Nm ramp via the latest firmware. Ibis deliberately picked Bosch over the trendier Avinox M2 to prioritise polish and warranty over headline figures. The 600 Wh internal pack is on the small side by 2025 standards (rivals running 720 to 800 Wh), but Ibis's chassis accepts the Bosch PowerMore 250 Wh range extender that mounts via a bottle-cage bracket, lifting total capacity to 850 Wh when needed.

Geometry and handling. Size-tuned head angle and reach progression: 63.9 degrees on S (445 mm reach), 64.7 degrees on M (467 mm reach), and 64.4 degrees on XM, L and XL (489, 513 and 536 mm). The 456 to 457 mm chainstay barely varies across sizes, but the head-angle adjustment cleverly tunes handling for the shorter S frame to remain composed and the larger frames to settle on faster terrain. Wheelbases run 1227 mm on S to 1338 mm on XL, a clean modern progression. At 140/130 mm of travel, the Oso S is squarely a down-country machine, not an enduro tool: the 63.9 degree S head angle is properly slack for the category and signals descent-capable confidence on tight technical terrain.

Build and value. Ibis publishes the Oso S as a single base trim with the SRAM Eagle 90 drivetrain. @Brawwp documents a 2025 Small build with the SRAM AXS wireless Transmission and Maxxis DH-casing tubeless tyres, which is a heavy tyre choice for a 130 mm bike but speaks to the durability brief. The standout build detail is the Bosch CX Gen 5 motor at Ibis's lightweight bracket: most rivals at this travel and weight use Bosch SX or Mahle. The Oso S goes the other way and pairs full-power Bosch with a 600 Wh pack, leaning on the PowerMore extender for longer days.

Community-verified strengths. Three things owners praise. The class-leading standover height noted by @Brawwp is a genuine usability win for shorter riders. The carbon frame quality and lifetime warranty on frame and bushings is unusual at this price point. And the Bosch CX Gen 5 motor's refinement is the right pick for riders who want polish over raw headline figures.

Caveats and known gripes. Three honest flags. The 600 Wh battery is small by 2025 standards: rivals at 130 mm of travel routinely run 720 to 800 Wh. Plan on the PowerMore 250 Wh extender being more than an optional accessory if you ride big days. @Brawwp's 2025 Small build was listed for resale at $4900 after only 16 miles, which is a cautionary note for the "carbon eMTB, partner not interested in MTB" buyer profile: this is a serious bike, not a casual cruiser. And Ibis distribution outside the US is narrow, with limited UK and EU dealer footprint compared to Specialized, Trek or Cube.

Verdict. The Ibis Oso S 2025 is the bike for the rider who wants a properly modern down-country eMTB with a carbon frame, Bosch CX Gen 5 motor and a low-standover, size-tuned chassis. If you want big-battery range or longer travel for enduro use, look at the Oso TR or Oso HD trims in the same family. Production status is current.