Mountain Bike Bends Around Turns, Literally: Rocky Mountain Instinct Carbon 70 AXS Review

Mountain bike design, especially suspension, involves managing tradeoffs. Weight, price, suspension travel characteristics, handling, and even pedal height (to avoid pedal strikes) must all be considered. The final set of compromises hopefully aligns with the designer’s original mission statement for the bike.

Rocky Mountain may have never received that memo, as its Instinct Carbon 70 AXS made it difficult to pinpoint what was given up to produce such a plush ride while maintaining favorable climbing and handling manners.

The Canadian brand seemed to obtain the perfect alchemy for a 150mm front and 140mm rear travel bike destined for all-day rides on unforgiving and unpredictable terrain. This plush bike also bends, quite literally, around corners, flexing in a way that makes it a scalpel on the trail.

Over the 8-month testing period, I logged everything from trail rides on Central Texas’s limestone-littered, hilly trails to downhill runs at a lift-served bike park. And throughout, I couldn’t really note a significant shortcoming while going up, down, or leaning over.

In short: If you want one bike that can efficiently handle fast trails with steep ascents while also being a capable downhill bomber for bike park days, the Rocky Mountain Instinct Carbon 70 AXS is an incredibly capable mountain bike. It’s a rare machine with no significant shortcomings and exceptional cornering manners.

Rocky Mountain Instinct Carbon 70 AXS Main Specifications

At an MSRP of $7,899, the carbon Instinct Frame would be expected to include nice componentry. The Instinct Carbon 70 AXS delivers. The componentry choices seemed intelligent. It mixes performance and durability while keeping the price of the bike out of the five-digit range.

Chassis

The Rocky Mountain Instinct carbon fiber chassis was a beautiful thing to unbox. The dual-tone yellow and brown gloss paint scheme looked and felt high-quality. The visible means of adjustability hinted at a bike made to conform to the pilot and not vice versa.

The shock eyelet on the rear suspension swing link has a four-position flip chip. This chip changes the head tube angle from 63.5 to 64.3 degrees (and related seat tube angle) with a single Allen key.

Without a UDH, the rear dropout allows the rear axle to adjust the effective chainstay length by 10mm. Our tester, which ran a SRAM GX Transmission (the consumer version will have SRAM XO Transmission), had to default to the 447mm chainstay length. The headset cups can be moved fore or aft 5mm to personalize the reach.

The downtube houses an in-frame storage area. It includes a custom-fitted gear “sock” and an Apple AirTag port on the large door. Cable routing is internal, with the housings clamped at the entry point on the side of the head tube.

Finally, every pivot point on the chassis is a fully sealed cartridge bearing.

Suspension

Rocky Mountain outfits the front of the Instinct with a RockShox Lyric Select+ 150mm fork and a Charger RC3 damper with a 43mm offset. The rear suspension duties come via a RockShox Super Deluxe Ultimate, which gets custom damping rates to match each frame size.

Drivetrain and Brakes

Rocky Mountain outfits the Instinct Carbon 70 AXS with an SRAM drivetrain that includes an XO Transmission rear derailleur wirelessly controlled via an AXS Pod controller. The crankset is made of GX Transmission aluminum alloy and has a 32-tooth chainring. The 12-speed rear cassette has 10 to 52 teeth.

The brakes are SRAM G2 GSC 4-piston units with resin pads.

The rims are Rocky Mountain’s own 30 AM Carbon. The rear hub is a DT Swiss 370 with an 18-tooth star ratchet. The front hub is an aluminum, sealed-bearing, house-branded unit. Tires are Maxxis Dissectors in a seemingly narrow 2.4″ width.

Cockpit and Wheels

The front cockpit hosts Rocky Mountain’s AM carbon bar and alloy 35AM stem with a 5-degree rise and a 40mm length. WTB supplies its Volt Race 142 saddle. The headset is an FSA Orbit with stainless steel sealed bearings.

The rims are Rocky Mountain’s own tubeless-ready 30 AM Carbons. The rear hub is a DT Swiss 370 with an 18-tooth star ratchet, while the front hub is an aluminum, sealed-bearing, house-branded unit. Tires are Maxxis Dissectors in a seemingly narrow 2.4″ width.

Our tester was a size L, and it weighed a verified 30.1 pounds without pedals or bottle cages.

Rocky Mountain offers the Instinct in nine different builds, including Shimano and SRAM drivetrains, Fox, RockShox, and Marzocchi suspension. Some builds have aluminum Instinct frames instead of carbon.

The Rocky Mountain Instinct Carbon 70 AXS on Dirt

Amazing Cornering Manners

I chose my local lift-served bike park for the inaugural ride aboard the Instinct. On the first run down the easiest trail, which had perfectly groomed high bowl turns, it was obvious that the frame had some lateral give.

Although frame flex is generally considered a negative, the forgiveness allowed the bike to “bend” around turn apexes. It was surprising, but it gave the chassis incredible cornering manners.

The faster I was going in the turn, the more I appreciated this “bending around the turn” characteristic. When I wanted to cut down on the bowl turn exits, it didn’t feel so forced and abrupt. I could turn down almost telepathically without deliberately tensioning my body to do so.

This inherent lateral flex helped on my fast, local, hardpacked trails, just as it did on the bowl turns at the park. But when crawling through hairpins or picking my way through rock gardens, I had to compensate and remember to expect a little sideways give. Slow maneuvering, especially forcing the back of the bike around through the pedals, required some extra oomph.

But the flexy cornering characteristic was one of the most enlightening of the year for me. I could smoothly carve a turn and didn’t feel the need to abruptly apply muscle power to get the bike to hit the exit I wanted. It felt like skiing big arcs instead of kick turns.

I considered the Rocky Mountain Instinct Carbon 70 AXS one of the best high-speed-cornering bikes I’ve ever used at the bike park.

Going Up

Climbing aboard the Rocky Mountain Instinct Carbon 70 AXS was surprisingly good, given the “trail plus” bike specifications.

I don’t ever think a bike with this much travel will climb quickly. I never try to race up the hills on bikes in this category. Approaching the Instinct with this stance revealed that it was a relatively capable climber. Even with the shock left wide open, seated climbing felt relatively efficient compared to other trail bikes I’ve tried.

Yes, there was some softness and bob, but it wasn’t as bad as other trail/enduro bikes. And the relatively low weight of the chassis and tires gave it a sprightly feeling.

The front wheel remained very planted and stable even on the steepest sections. I didn’t employ radical body positioning to keep the bike driving upwards with the front tire down. The rear wheel was the same. It felt further back than it was, giving me a stable base while eating up the smaller steps and ledges without breaking stride.

For having such a compliant suspension feel, the Instinct was a great ascender.

Going Down

After being wowed by the Instinct chassis’ turning capabilities on the easier runs, I started riding the chunkier, more advanced trails at the bike park.

Fork Action

These runs involved rocky ledges, sometimes many in a row. The trails are embedded with rocks of all sizes, from tennis balls to basketballs. The Rock Shox Lyric Select+ fork felt amazingly plush right away with the suggested air pressure and clicker adjustments.

These suggested settings placed me firmly in the middle of the low and high-speed damping adjustment ranges. The compression and rebound damping was super-compliant, and I felt zero stiction during the initial travel. This kept the tire on the ground while minimizing high-frequency chatter.

As the front wheel moved into the midstroke, the compression damping ramped up predictably. I didn’t feel the sudden increase in resistance that I’d felt in other longer-travel air spring forks. As the fork compressed all the way through the available travel, that same predictability in damping carried through, and I never had a harsh bottom-out or had a wheel skip out due to incorrect rebound damping.

Shock Performance

The Super Deluxe Ultimate shock wasn’t as free-feeling in the initial travel. However, it had a super-planted feeling mid-travel and beyond. The shock delivered a calm ride quality, especially when bombing down successive ledges.

My favorite and fastest section has about 100 yards of successive limestone ledges that are about 10-24″ tall. The section is straight but steep. Speeds are among the highest in the park. The shock’s composure in the meat of the stroke, combined with the compliant yet supportive fork, produced my fastest runs ever through this section. And I never felt anything but in control.

The rocker shock mount’s flip chip has four available positions. I chose the position that gave the bike the second steepest angle. After rotating through all the settings, I returned to that one and left it.

The rear dropout flip chip wasn’t adjustable on this bike since it used a UDH. I also left the headset adjustment cups in the zero-offset position. This ability to adjust these three parameters to suit body dimensions and preferred geometry was a unique and usable feature.

Other Rocky Mountain Instinct Carbon 70 AXS Ride Qualities

The Instinct was an enjoyable bike on the trails and at the bike park, thanks to its amazing cornering manners and capable suspension. The rest of the bike followed suit.

The SRAM AXS wireless shifting was a joy to use. No matter how much the bike bounced around, the large buttons, distinct “click,” and traction-enhancing surfaces of the shifter pod, combined with the SRAM GX (XO on consumer bikes) Transmission, made gear changes a non-issue. I never once missed a shift. This was true even when the chain was under extreme tension while climbing or accelerating out of a turn.

The SRAM G2 GSC brake pads took a long time to bed in. But once they did, braking was reliable and predictable. The initial bite wasn’t as crisp as Shimano units, but the progressiveness and maximum stopping power suited the bike’s intended purposes well. Again, like the shifting, I rarely thought about braking; I just did it instinctively.

I assumed that I would want to switch to 2.6″ wide tires. The 2.4″ Dissectors seemed to narrow for the amount of travel and chunk factor of my local trails. But I was proven wrong. I enjoyed the light feeling while climbing and accelerating. And not once, even when climbing steep and loose pitches, did I yearn for wider rubber.

Conclusions on the Rocky Mountain Instinct Carbon 70 AXS

The standout characteristic of the Instinct Carbon 70 chassis was its ability to carve turns. I have never felt this “bend around turns” in a carbon bike. I’ve felt it in steel and titanium road bikes and on motocross bikes. It was refreshing to feel it on the Instinct, and it gave me a hopeful outlook on the development of future carbon frames.

I realized while riding at speed in turns that my assumption that all carbon frames are unequivocally stiff laterally by design was wrong. Let’s see some more “bendy” bikes so we can flow through turns, seemingly without effort.

The rest of the bike’s characteristics were favorable, meaning I didn’t have to apply much thought or any undue effort to get the bike to do what I wanted. And for a bike of this nature, it definitely was light and felt that way going up and on lean.

I think Rocky Mountain has a winner here. It can expand upon the revamped chassis’ cornering prowess. I’m a huge fan of the cornering manners and hope to see more bikes like this in the future.