First Ride Review: Ibis Oso

As an Ibis Stockist and Demo Centre we’re lucky enough to ride the latest bikes from the Californian brand on our home trails around the Tweed Valley. The Oso marks Ibis’ first foray into the e-bike market; with slack angles, a 170mm fork and 155mm of rear travel its intentions as an enduro e-bike are clear. But how do these numbers translate on the trail, is the Oso a one trick pony? To find out, we gave Tom our Large Demo bike and sent him out to hit the trails and get some first impressions on the Oso. 

Frame, Suspension and Build

Progressive in both geometry and suspension design, the carbon framed Oso has received the longer, lower and slacker treatment from the outset. Featuring the longest reach figures of any Ibis bike, the size Large measures a whopping 500mm reach for a rider between 170-185cm. Balancing out the long front end are size specific chainstays and wheel sizes; the Small and Medium bikes run MX wheels and receive a 439mm chainstay, while the Large and X-large bikes both use 29” wheels and a 444mm rear end. The longer reach and chainstay figures are complemented by a slack head angle of 64° to give a confident ride over fast and rough terrain. A seat angle of 78° on the size Large is sufficiently steep to allow the Oso to be comfortable for a taller rider and the low slung frame paired with a long stroke dropper, means there is ample room to move around on the bike. The Oso, like all bikes from Ibis, is backed by a lifetime warranty on the frame, frame bushings and rims for the original owner. 

As with all full suspension bikes in the Ibis range, the Oso uses a DW-Link layout to deliver its 155mm of rear travel, which can be increased to 170mm by fitting a longer stroke shock. Designed with a leverage curve to help support the increased weight of the motor and battery, the Oso’s rear suspension increases in progression by 25% through the travel, keeping the bike higher and offering a smoother ride. 

The shock tune also plays a part in how smooth the Oso can be over chunky terrain; the ability of the DW-Link to provide support without relying on compression damping to reduce pedal bob means the shock of the Oso can be run with much less overall damping, allowing the bike to quickly react to lumps and bumps in the trail.

Damping duties on the Oso are handled by Fox, with a 170mm 38 Performance fork and a Float X2 Performance Elite rear shock fitted as standard. It’s worth noting that the Oso is coil compatible, and can also have its rear travel increased to 170mm with a longer stroke shock. Up front, up to a 190mm fork can be fitted and the bike is even rated for use with dual crown forks for riders who want the closest thing possible to a DH bike with a personal uplift.

Built around Bosch’s Performance Line CX motor, the Oso delivers a peak torque of 85Nm and max power of 600W. Four assistance modes are available, from the range stretching Eco and Tour, to the all the power all the time Turbo, with the adaptable eMTB mode sitting in the middle. Medium, Large and X-Large bikes come fitted with a 750Wh battery and the size Small comes with a 625Wh unit. Both should provide more than enough capacity for long, all day rides in the more economical modes, as well as keeping you fully powered on the shorter, higher speed blasts.

Maxxis DoubleDown MaxxGrip tyres come fitted as standard to Ibis’ own brand and lifetime warrantied Blackbird Send wheels, giving increased sidewall support and puncture protection to match the descending focused intentions of the bike. Tying in with the theme of maximising the downhill capabilities are the brakes and rotors. Shimano XT 4 piston brakes clamp onto 220mm rotors for huge stopping power whenever you need it without any overheating worries. 

Neatly integrated features can be found all over the frame; from the small mudguards strategically placed to protect the rear shock and linkage from the worst of the mud, to the rear light built into the seat clamp to keep you safe on night ride town transfers. Ibis have used their decades of experience in frame design and carbon fibre to come up with a unique looking, well executed and high quality ebike. 

Riding the Oso

Initial setup

Ibis provides a detailed suspension guide for the Oso on their website, not only listing suggested baseline pressures and settings but also explaining various aspects of suspension setup. From compression and rebound damping to air pressure and volume spacers, it’s all there for any new owner to reference. To quickly find my baseline suspension setup I referenced the guide which gave me my initial pressures of 205psi in the shock and 97psi in the fork. I’ve spent a fair amount of time on Fox suspension so felt comfortable setting rebound and compression to my preferences. 

The only other setup change I made to the bike was to reduce the bar width. I prefer a slightly narrower bar, running 750mm on my own bike. Reducing the bar width on the Oso is a simple job thanks to threaded 25mm inserts on either end of the 800mm bar. Simply removing these put me at my preferred bar width without having to commit our demo bike to a permanent change. 

Climbing

From the first fireroad climb it became obvious that Ibis have put a serious amount of time and effort into their rear suspension. Producing minimal pedal bob with the climb switch open, the Oso is one of the most efficient feeling e-bikes I’ve pedalled. After experimenting with the climb switch on the fireroad climbs around the Tweed Valley and feeling no significant difference between settings, I left it open for the rest of my time on the bike. Being able to comfortably climb with the shock open lets the suspension stay more active, so when you come to a rougher section of climb, or a technical move, the bike is able to keep the rear wheel in traction and make the most of the power you’re sending its way from the motor. This was noticeable on some of the most ‘direct’ climbs around the Tweed Valley, the rear wheel stayed planted, the steeper seat tube angle kept me central through the pedals and I was able to claw my way up some really steep sections.  

With 85Nm of torque on tap from the Bosch motor, and four assistance levels to choose from, you can ride the Oso however you’d like. There’s a large scope of assistance between the four modes, each one feeling distinctly different from the last. Fairly quickly, my go to mode became eMTB; constantly varying the output based on your input, eMTB is quick to react and smooth with the power delivery meaning you don’t need to worry about adjusting the system, you can just ride as you normally would and let the motor figure it out. 

Overall, I found the Oso a comfortable bike to climb, the steeper seat tube angle places you nicely over the pedals without becoming so steep as to put pressure on your hands on flatter sections. I’m 183cm tall and the 185mm BikeYoke Revive dropper post put me at a comfortable pedalling height and still gave me plenty of room to manoeuvre when the trail turned back down the hill.

Descending

My first thought when riding the Oso down a trail was how low the frame feels, which translated to being able to move the bike underneath me a lot more than I was expecting for an e-bike, opening up a lot of range of motion. This ability to get low to the bike really gave me confidence as the trails got steeper and more technical. 

Lightly damped Traction Tune suspension allows the wheels to flutter across the trail and leads to a smooth ride, this was especially noticeable on flatter sections of trail with lots of small but repeated hits. The Oso carried speed across these sections incredibly well, and felt very composed, as the rear wheel is so free to move out of the way of obstacles. I did end up slowing the rebound speed of the shock down by a couple of clicks, as the Traction Tune allows for much faster rebound speeds than on a conventional shock, but otherwise I was happy with how the bike was performing. 

For what is a very long bike, the Oso rode through tighter sections of trail with finesse and I never felt as though I had to majorly change my riding style to accommodate the extra length. With its progressive rear suspension and lightly damped shock tune, the Oso is lively and active on trail, responding well to inputs and deals with the steepest and most technical trails at the Golfie with ease. To suit this bike more to my personal preferences I might have ended up fitting a higher rise bar, as on the steepest of trails I found the front end a touch low. However for 90% of my time on the bike this wasn’t really an issue and I do prefer a higher front end on my bikes.

Where this bike really came alive though, was on the faster and more open trails. Here the Oso felt like it was in its element, encouraging me to push into the turns harder and stay off the brakes longer as the chassis just chewed up anything that came its way. Exposed root sections just became a minor bump in the trail and, held up by the progressive rear suspension, I was able to pump berms without any feeling of wallowing in the travel. It was on these trails that the geometry figures really clicked for me; 444mm chainstays on the size Large kept the rear wheel glued to the trail and gave an excellent balance of weight front to back, meaning the Oso felt stable and controlled at high speed, but this isn’t to say the Oso becomes a chore to ride on mellower trails. A few laps of trail centre terrain revealed a side to the Oso that’s fun and engaging when the trail gets simpler. Having the ability to switch between stable enduro race bike and dynamic trail bike is a trick not many can pull off but the Oso manages with ease. 

Final Thoughts

The appearance might be unique, perhaps even a bit marmite-y, but the Oso delivers a convincing ride; with well balanced geometry and a highly developed rear suspension design coming together to create a bike more versatile than a quick glance at the numbers might suggest. Top this off with factory supported travel changes, a well thought out parts selection, as well as lifetime warranty on the frame, frame bushings and rims, and the Oso is a promising prospect for any rider looking for a new e-bike with a descending slant. 

Don’t take our word for it, book an Oso demo bike and take one out on your favourite Tweed Valley trails.

01896 831 429

shop@tweedvalleybikes.co.uk