When Gear Institute began looking for bikes for the upcoming Gravel Bike Best in Class roundup, one of the top mountain bike brands, Niner — who also does cross bikes — didn’t have one available in our price range. Nevertheless, they sent in the RLT 9 RDO 5-Star Ultegra Di2 anyway, which is their top-of-the-line gravel rig, and simply one of the best overall bikes I’ve ridden. It’s going to hurt to give it back, but first I’ll share with you why if I could afford one — it’s an $8,800 bike! — I’d buy it. Today.
Gravel (aka all-Road or adventure) bikes are a recent sub-category of road bikes that’s absolutely the hottest trend in cycling right now, and is helping save an otherwise slumping road bike industry. That’s probably because, despite the industry’s best efforts to make a niche bike for every surface possible, gravel bikes can handle almost every type of terrain from pavement to dirt to rocky trails. Consumers truly have that elusive “one-bike-to-ride-it-all” available to them now. While these won’t handle the most hardcore endeavors, like serious trail riding, road racing, etc., they do everything else well enough to handle the general needs of the large majority of generalist cyclists.
Frame and Overall Features
The Niner RLT does all-of-the-above beautifully. It’s lightweight, at just over 18 pounds it’s nearly as light as race bikes, with stiffness where you need it and compliance where you want it. While many of these bikes fall decidedly on the gravel side, the RLT sits solidly in the middle: The frame is super responsive, even under heavy loads like out-of-the-saddle sprinting, flexing even the stiffest race bikes. But that stiffness is countered by flex and compliance where needed for off-road riding, especially in the seatstays and seatpost, both of which absorb bumpy road chatter and gravel surfaces impressively.
That’s a combination of geometry and tube design: The angles of the RLT are more road-focused than many gravel bikes, using a slightly steeper head tube and shorter chainstays which help with power transfer. But it’s still much more relaxed than racing rigs, which keeps it comfortable on all-day rides on rough terrain. Imagine an endurance bike with wider tires and a beefier fork. That beefier fork is key too: While gravel bikes need compliance in the fork to absorb bumps and rocks, they also need to remain stiff for control on loose terrain. The Niner’s fork is impressively stable in hard cornering over dirt and gravel, but still allows a fairly smooth ride up front — albeit not as smooth as more gravel-focused bikes. On the road, combined with the stiff frame, this fork excels with quick, stable and predictable turning, which is uncommon on these rigs.
Wheels and Components
This leads to the rest of the build. First, an outstanding set of hoops puts this bike at a whole other level compared to most gravel rigs. ENVE’s SES 4.5 AR Disc wheels are a perfect combination of shock-absorbing, wide, aero, and light. The first two mean a smoother ride, thanks to a long carbon rim to dissipate vibrations. And the wide profile, which can handle tires up to around 40mm wide, provides the platform these tires need to perform at their best. The latter two mean additional speed on the road and the ability to maintain momentum that eludes most bikes in this category. When you hit a hill, this bike doesn’t feel like a lead weight — it responds quickly and easily (although it’s definitely not a climbing bike). The spec’d Schwalbe G-One tires (35mm) are well suited for a combination of paved and dirt road, but lean toward sealed surface use. For serious off-road use, riders might want to swap for a deeper tread.
All of that is complemented by Shimano’s Ultegra Di2 group with hydraulic disc brakes, and as we’ve mentioned before, this is among the best overall component groups available anywhere. And it’s perfect for the rigors of gravel cycling, thanks to its ability to shift and brake with minimal hand movement and finger strength — you’ll need those for keeping the bike under control at speed on rough, loose terrain. And that shifting is consistently quick and precise; a rough ride does not mean rough shifting. We found it highly consistent regardless of terrain, whereas with mechanical shifting we were more reluctant to attempt shifts on bumpier sections.
Overall, the Niner RLT 9 RDO 5-Star Ultegra Di2 is a no-compromise dream bike, purpose built for flying over dirt roads/trails, cobbles or torn-up pavement, and it’s equally at home on long smooth road rides — even a race or Gran Fondo — as it is on the rough stuff. It’s also one of the most expensive gravel bikes out there. But if you’re looking for one bike to do it all — and do it well — its outstanding and rare mix of road-bike performance and gravel-bike capabilities should put it at the top on your list.