Building a trail bike can't be easy. You're forced to settle on a design that should somehow climb like a goat, but also eat rough descents with ease. Recent geometry trends have greatly improved rider weight balance and overall handling, howeverRocky Mountain’s 2021 Instinctoffers solid modern geoandenough adjustability that everyone should be able to tune this bike to suit their terrain or riding style.
Rocky Mountain has refined its linkage and frame geometry to make the new Instinct a balanced, stable, and versatile trail-eating machine. I have theInstinct Carbon 70Since the snow in B.C. melted and although I lost a few weeks to a rib injury I've now tested it on many different trails and experimented with its geometry adjustments.
Even without its adjustable geo, I'd still call the Instinct a solid contender in the one-size-fits-all class, but with variable chainstay length and the Ride 9 chip, the Instinct offers something some bikes don't—multiple personalities and plenty of which possibility for fine tuning.
2021 Rocky Mountain Instinct frame details:
look at minestart articlefor full details on the 2021 Instincts, but here are some important notes about the new design:Der Instinct Carbon 70features Rocky Mountain's recently redesigned Smoothwall carbon frame and offers 140mm of rear travel (with 150mm forks on all models). The XL, Large and Medium frames roll on 29" wheels, but RMB runs 27.5" wheels on XS frames and small models have a choice of 27.5" and 29" wheels. wheels.
The new Instinct's Smoothlink linkage has been redesigned to improve pedaling efficiency and handle rough descents better. The melody of instinct differs fromamount of RMBEnduro bike that prioritizes all-day pedaling performance over big hitting abilities. The Instinct's reshaped front end tubes and dual bearings at the chainstay/seatstay junction both improve frame rigidity.
Rocky Mountain keeps its weights well in check: the medium-sized Instinct Carbon 70 weighed in at 31.81 lbs (with pedals).
Suspension setting:
With its revised linkage, the new Instinct has air pressure similar to Rocky Mountain's Altitude and requires more psi than the usual "bodyweight" setup. You'll need to look at Rocky's setup chart to find your starting point, but beyond that the Instinct requires no special tuning. I weigh 145 pounds and I run 180psi in theFox Float DPX2 damper. My compression is two clicks from wide open, and I started the rebound at 11/15 clicks to the fast end. I've been playing around with the Instinct's rebound, and I'm glad I did...more on that later.
I'll run those in advanceFox 36 Fit 4 Performance Elite-Gabelat 70 psi (within recommended range) without token. I have the HSC wide open and +2 clicks from LSC. Rebound is close to recommended values with LSR at 9/15 and HSR at 8/9. The fork setup seems pretty good as I generally use about 90% travel but hit rock bottom on a fast rough run or during a hard G-out.
Geometry:
Given this bike's "trail" nickname, Rocky Mountain did a great job of finding a comfortable, versatile range of geometry for the Instinct that keeps up with modern trends—and is adjustable in two ways. The 2021 Instinct features Rocky Mountain's Ride 9 chip, which changes the bike's geometry and shock rate, and a chainstay flip chip, which shortens/lengthens the rear end by 10mm.
In fully slack mode (pos. 1), the Instinct's reach is 456mm, the head angle is 65.1°, the seat angle is 76.1° and the bottom bracket has a drop of 43mm. In the steepest mode (pos. 9), the reach increases to 468 mm, the head angle steepens to 66.2°, the seat mast tilts by up to 77.2° and the bottom bracket drops significantly to 28 mm.
The rear triangle length and wheelbase of the bike only change 2mm with the Ride 9 chip, but the 10mm chainstay flip chip lets the rider play with distinctly different short and long modes. The shortest tail adjustment is 436mm and the longest is 448mm. Visit RMB's website to see the geometry specs for each Ride 9 chip position.
Driving impressions:
Speaking of geometry, I'll start my riding impressions there. I'm 5'10" and find the medium Instinct 29er very comfortable. The 456mm reach in fully slack mode feels great and gets me in a centered body position without stretching my arms out too much to whip the bike around when needed. I did most of my testing in the Instinct's most relaxed pose. 1 as that suits my steep, rough local trails.
I really like this bike when it's totally relaxed. It offers near enduro handling (especially in long mode). However, its medium travel is a very fun bike that blasts through rough trails but doesn't let you get lazy! I'd say a head angle of 65.1° is perfect for this bike - fairly slack but never heavy for technical trail riding.
While it contributes to the bike's stable ride, the Instinct's BB sits fairly low once the bike has let up. I've regularly marked cranks on low-lying obstacles, so tread carefully on rougher climbs.
Even in pos 1, the Instinct's seatmast is steep, putting you in a good position for pedaling. As today's bikes get better with their front-back balance, I tend to stay in the saddle more on climbs, and the Instinct was no exception. Traction on both wheels is very good, and only the steepest climbs required a righting effort rather than a slight forward lean.
For my recent rides, I have the Instinct's Ride 9 chip in pos. 7. The 464mm reach immediately felt longer, but I quickly got used to the change. It's long but not too long, so I still found the steering comfortable on descents. The increased reach definitely puts you in a great position for powerful pedaling: I was happy with the slack bike, but it only climbs better if you steepen the angles. Pos 7 just leaned me forward a bit more and it really emphasized the bike's climbing abilities.
The slightly steeper 65.8° head tube angle is noticeable, but I found it helped more on the climbs than it hurt on the descents. The steeper and shorter settings (I was in Short mode when testing pos 7) let the Instinct whip through switchbacks, but its modern geo keeps the bike from ever feeling unsteady.
The BB lifts to a 34mm drop in pos 7 and I still marked a pedal here and there, but definitely less than with the Instinct eased. I certainly didn't notice a huge loss in stability at high speeds, but lower is definitely better if downhill thrashing is your thing.
My legs are a little long for my height, but I don't have any issues with the Instinct's overhang. Up front, the stack height (610-619mm) gives the bike a pretty aggressive stance, even in slack mode.
Short/Long modes:
The Instinct is already a very balanced bike in short mode. At 436/438mm, RMB doesn't offer the thickest suspension on the market, but they've found a reasonable balance between agility and stability/traction. Climbing traction is already very good, and given its generous reach, the Instinct feels “dead between the wheels” in all settings. In short mode, the Instinct handles tight switchbacks with ease, just as you would expect from a trail bike.
On the descents, the rear end feels quite right for the bike in short mode. The Instinct handles tight corners fairly well given its modern dimensions and offers good stability due to its fairly long wheelbase and low bottom bracket (when relaxed).
While flipping the dropout chip makes a noticeable difference, in long mode the Instinct doesn't feel like a whole different beast. It definitely enjoys a small boost in stability and slows down a bit in corners, but it doesn't suddenly become an enduro bike.
I find it interesting how much I like the longer rear triangle for climbing. Again, cornering is a bit slower, but I haven't ridden a single switchback that made the bike feel uncomfortably long. Where I really appreciate the longer rear end is on steep climbs. With the wheelbase increased, it seems like your body position needs to be far away to impede traction. When a steep climb pushes your weight backwards, the rear wheel just seems to gain traction and the front end doesn't want to lift like it would on older, shorter bikes.
On descents, the longer rear triangle feels great and provides impressive stability at high speeds. The longer chainstays slow down your turns a bit, but I found that only the tightest of technical turns required a little extra swing in the hips. On faster flow trails or any kind of berms, I didn't feel like Long mode slowed me down at all.
With the Instinct, the terrain will most likely dictate the rider's preference for the short or long mode. Unless your home trails are particularly steep or rough, I'd say that Short mode offers the best all-around geometry for trail touring. However, if you have a few gnarly trails at hand, in Long mode the Instinct offers the most stable ride I've experienced from a mid-travel bike to date.
Suspension – Climbing:
While I would like to say thatInstinctis the best Rocky Mountain I have ridden so far, I still prefer to climb with the rear shock in fixed mode. The RMB linkage is very active initially and moves freely to soak up small bumps, which it does well, but I find that using the shock's firm setting greatly reduces pedal bob. Even in fixed mode, traction is very good on technical trails and if you hit something hard it willFox DPX2 damperwill still open to accommodate it.
While the initial stroke is soft, the Smoothlink linkage doesn't wallow under pedaling efforts and uses about 50-60% of travel on a singletrack climb. I also noticed that the Instinct's stand-up pedal performance was very good, withstanding severe bobbing under hard exertion (with the damper firm) and maintaining forward momentum well. Climbing technical trails with the shock in medium or open mode, the linkage keeps you floating at half travel, giving you optimal traction for a small loss in pedaling efficiency.
I rode most of my test in the loosest/most progressive ride 9 chip pose. 1 but I jumped to pos 7 for my last few rides. Moving towards pos 9 does make the shock more linear, but on climbs the Instinct's linkage refused to acknowledge this and kept me cranking at about half travel.
Descending:
Given the steep terrain in my area, I was keen to keep the Instinct in its loosest position, but I've had issues with other RMB bikes ramping up too much for me in this environment - I'm a lightweight at 145lbs. I was pleased that the Instinct's linkage felt less progressive than the Altitude's, and I had no trouble grounding the bike in the slackest Ride 9 chip position. Both bikes have a spacer in the rear shock and I regret not pulling it out of the Altitude, but I don't feel the need on the Instinct.
Now I don't want to say the Instinct is too soft or squishy: there's still enough mid-travel support to give the bike the RMB's characteristically lively ride, and it takes a good punch to full travel squeeze out the back end.
After a few rides, I found the rear end quite poppy and decided to call that back. I slowed the rebound down 5 clicks and it did what I wanted in an obvious way – the bike felt a lot more plowing through chattering, rough spots and a lot less bouncy. The rear tire rolled through bumps instead of bouncing over them, and I felt a noticeable improvement in traction and handling in rough sections. I added two clicks back (faster) after this round and the ride is now well balanced, soaking up repeated hits well but still feeling lively and poppy. I start with each test bike near or within the recommended suspension settings, but I liked the Instinct with a little less rebound and will keep that in mind for future RMB reviews.
Expecting a more linear shock rate, I added 5 psi to the Instinct's rear shock as I moved into pos. 7. On bumps, I've noticed that the bike dips a little deeper into the travel more easily, but only up to a point: also in pos. 7 the end stroke ramps up nicely, so the few psi I added was mine almost the same bottom-out resistance as pos. 1.
RMB says the Instinct is built with the same stiffness as the Altitude enduro bike, and while the mid-travel Instinct needs a little more body language to stomp through rough terrain, it holds its line pretty well.
Components:
I was pleased to find that the 150mm Fox 36 Fit 4 Performance Elite fork could easily be tuned soft enough for my liking. I've found other Fox forks to be hard to reach, but even with my air pressure within Fox's recommended range, I got every millimeter of this one on those harder hits.
I've now ridden several sets of Race Face AR 30 rims without causing any significant damage, but after this test I'm really impressed with them! I hit a sharp rock very hard on one ride, slashing the Instinct's rear tire and making a startling noise, but I can't even tell where the rim took the impact and it's still dead straight. Good stuff!
As far as the Instinct Carbon 70's XT drivetrain and trail four-piston brakes go, I'd say no complaints. Shifting is reliable and crisp, and the brakes are rather grippy, but I appreciate their stopping power and can modulate them well enough.
The cockpit of the Instinct offers a nice short 40mm stem and while I wouldn't say no to 800mm wide bars, I'm happy with the 780mm Race Face Turbine R bars. ThatErgon GE1 EVO Griffeare also a nice ergonomic touch.
I haven't had any problems with the crank or BB and always happy to see good old ones.Maxxis Minion DHF/DHR EXO tireson every bike. Quick note - I don't think any trail rated tire would have survived the rock fall where I cut the rear open!
I haven't had a good experience with Race Face's Turbine R dropper posts. Unfortunately, the 150mm model of the mid-range Instinct was no exception. The posts almost always stick fresh out of the shed on the first lift and often stick out below the max height or stick down while I'm on the trail. On the plus side, I find the WTB Volt Race saddle comfortable on my butt.
The Instinct Carbon 70 costs at retail$6899. Frame sizes XS/S/M/L/XL are available. The Carbon 70 model is sold in two colorways – Violet Hills/Enter Sandman/Black Dog (as tested) or Ice Ice Baby/UD Carbon Matte/Black Dog.