Home > Bike Types > Mountain Bike

Rocky Mountain Bikes sharpens their Instincts for evolving trail performance

Rocky Mountain 2021 Instinct, rider cornering
Support us! Bikerumor may earn a small commission from affiliate links in this article. Learn More

There’s something to be said about one bike that can do it all. Rocky Mountain Bikes is continuing to streamline their models, and the updated Instinct now serves as their most versatile, mid-travel trail bike. With 140/150mm of travel and re-tuned Smoothlink suspension, RMB has revised the Instinct to eat up miles of trail while handling aggressive riding better.

Many features introduced on RMB’s recently updated Altitudes carry over to the new Instincts: Most notably the frame tubing is similar, smaller frames ride on smaller wheels, and the Instinct gets a +/-10mm chainstay length flip-chip.


With the release of the revised Altitudes, RMB dropped their Instinct BC model and absorbed it into the Altitude lineup. They’ve now done something similar with the Instinct: Rocky Mountain is discontinuing their 27.5” Thunderbolt bikes, relying on the updated Instinct line to serve our mid-travel needs.

2021 Rocky Mountain Instinct frame updates:

Rocky Mountain Bikes 2021 Instinct, angle

The new Instinct offers 140mm of rear travel, and all models come with 150mm forks. Complete bikes are available with Smoothwall carbon or FORM Alloy frames. The Instinct now looks similar to the new Altitudes, with an updated tubing profile that provides increased front end stiffness.

The Instinct features dual bearings in the chainstay/seatstay junction, shielded bearings in all pivot points, and the carbon frames use a modular bolt-on shock mount. Both wheel sizes can fit tires up to 2.6” wide, and chainrings up to 34t.

Rocky Mountain Bikes 2021 Instinct, top tube

Carbon Instinct frames feature fully guided internal cable routing, while the alloy frames utilize large ports for easy cable access. Both can host North American or moto brake setups, and keep the cables from rattling.

Rocky Mountain Bikes 2021 Instinct, chain guard

The Instincts come with OneUp Components’ V2 chain guides, held up by RMB’s new Canadarm mount. The frames also include a full-length downtube protector, a noise-cancelling chainstay guard, and Rocky’s Canadian Shield mudguard behind the BB.

Rocky Mountain Bikes 2021 Instinct, suspension chart

While it shares many design features with the new Altitudes, the Instinct gets its own unique suspension tune. The Altitude is designed for aggressive trail riding and enduro racing, whereas the Instinct was built to pedal all day long.

Generally speaking RMB’s suspension curve aims to provide a soft initial stroke, supportive mid-stroke and progressive end-stroke. The bikes also include size-specific suspension tunes including smaller 190 x 45mm rear shocks for the two smallest sizes to allow for a smaller frame and lighter suspension kinematic. Medium through XL frames get a 210 x 52.5mm rear shock, while all frames run 140mm of rear travel.

Wheel size split:

Rocky Mountain Bikes 2021 Instinct, frame standover graphic

RMB has set up the Instinct with different wheel sizes on different sized frames. The XS Instinct will come on 27.5” wheels only, but the Small frame will offer riders their choice of 27.5” or 29”. Medium, Large and XL frames roll on 29’s only.

To accommodate shorter riders, the XS and Small Instinct frames offer a different shape with a lowered top tube and reduced standover height. RMB also offers size-specific suspension tunes on their bikes so whether you’re buying an XS or an XL, you shouldn’t have to go to extremes to get the suspension set up properly.

10mm dropout flip-chip:

Rocky Mountain Bikes 2021 Instinct, dropout flip chip

Another feature of RMB’s updated frame platform is a 10mm chainstay length adjustment. A flip-chip in the rear dropout allows you the choice of riding in Short or Long mode, opting for more agility or better stability. RMB supplies their own flippable brake mount (which fits a 180mm rear rotor) and in Long mode the frame is compatible with SRAM’s UDH universal derailleur hangers.

Ride 9 chip:

Rocky Mountain Bikes 2021 Instinct, Ride 9 chip

The new Instinct features Rocky Mountain’s Ride 9 chip, which adjusts the frame geometry and shock rate. Head and seat tube angles don’t change by much across the chip’s nine positions, but the frame’s reach ranges by 12mm’s and stack height varies by 9-10mm. Chainstay length and bottom bracket height are not affected by the Ride 9 chip.

Shock rate is noticeably affected as you move the Ride 9 chip from one end to the other. The steeper the bike gets the more linear the shock feels, and as you go slacker the shock’s progressivity ramps up. Adjusting the chip is pretty simple, you just have to look up which setting is which!


Rocky Mountain Bikes 2021 Instinct, geo chart

Check the above chart for all the particulars, but here are a few notes on the Instinct’s updated geometry: The new frames offer generous reach numbers, ranging between 456-468mm for a Medium and 481-493mm for a Large. Head tube angles range from 65° to 66.6°, while the seat masts are all between 76-77.6°.

Out back, chainstay lengths for 29ers are the same across all sizes, and can be as short as 436mm and grow up to 449mm depending on the dropout position and Ride 9 chip. The 27.5” frames rear ends range from 425-439mm.

2021 Instinct model lineup:

Rocky Mountain is offering the new Instinct line in six carbon builds (plus a carbon frame kit) and two aluminum models. All models are available now, and since there are so many check out RMB’s website for build specs on each. Frame color options for all models are Ice Ice baby/UD Carbon/Black Dog or Violet Hills/Enter Sandman/Black Dog (with framesets only available in the latter).

Rocky Mountain Bikes 2021 Instinct, Carbon 99, side
2021 Instinct Carbon 99

Instinct Carbon 99: $10,449

Instinct Carbon 90: $9,399

Instinct Carbon 70 Coil: $7,629

Instinct Carbon 70: $6,899

Instinct Carbon 50: $5,549

Instinct Carbon 30: $4,499

Rocky Mountain Bikes 2021 Instinct Alloy 50
2021 Instinct Alloy 50

Instinct Alloy 50: $4,499

Instinct Alloy 30: $3,129

Rocky Mountain Bikes 2021 Instinct frameset
*Title and studio images c. RMB

Instinct Carbon frameset: $3,549

As for complete bike weights, the lightest Instinct 29er build is the Carbon 99 model at 28.8lbs, and the heaviest is the Alloy 30 model at 34.7lbs. The 27.5” builds come in a bit lighter, weighing 0.4 to 0.8lbs less than their 29er counterparts.

The 29” carbon frameset (with Fox DPX2 shock, chain guide, frame protectors, seat collar and axle) weighs 6.9lbs in size Medium, while the 27.5” frameset weighs 6.5lbs in size Small.

Initial Ride Impressions:

Rocky Mountain Bikes 2021 Instinct, Steve Fisher climbing

Due to an unfortunate late blast of winter weather, I got skunked on several chances to ride the Instinct Carbon 70 thus far. Luckily RMB will be leaving the bike with me for a while longer, and I’ll have a full review coming later this summer. I have pulled off three short laps on the Instinct, so here are my initial impressions of it…

Geometry wise, the medium frame fits me well at 5’10”: Standover height is good, and I like the 456mm reach (I have the bike in its Slackest setting). With the steering angle at 65° the Instinct offers a fun ride, as it maintains easy handling through rough terrain yet its 140mm travel still encourages you to pick lines wisely and use a little body language on chunky trails.

I’m happy to report I find the Instinct to be an excellent pedaller. I do use the Fox Float DPX2 rear shock’s Firm setting to climb, even for most singletrack, but in that mode the Instinct keeps your energy moving forward quite nicely. During one stand-up burst I noticed the bike held its momentum really well, hardly allowing any bob despite my choppy pedal stomping. I can’t wait to take this bike further!

That’s about all I can say for now, but once I’ve played with the Ride 9 chip, dropout adjustment and put many more miles on the Instinct Carbon 70 I’ll post a full, proper review. For complete details on the 2021 Instinct lineup visit Rocky Mountain Bikes’ website.


Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Inline Feedbacks
View all comments

Subscribe Now

Sign up to receive BikeRumor content direct to your inbox.

Subscribe Now

Sign up to receive BikeRumor content direct to your inbox.