For 2021 Rocky Mountain Bikes has elevated their Altitude to become a full-on enduro machine. The completely redesigned frame offers more travel, and now includes adjustable dropouts that add or remove 10mm of chainstay length. RMB also decided to introduce different wheel sizes, dependent on frame sizes, with the new Altitudes.

Rocky Mountain Bikes 2021 Altitude, rider, side

For the last few seasons the Rocky Mountain/Race Face Enduro Team had been riding RMB’s Instinct BC Edition 29er, but the brand has decided to quash the Instinct BC. The new longer-legged Altitude bikes now comprise Rocky Mountain’s enduro lineup.

I recently received an Altitude Carbon 70 to test, but I’ve only had a few chances to ride it. I’ve included my initial impressions in this article, but don’t worry if you’re hoping for more details, I’ll have a long-term review posted later this fall.

2021 Rocky Mountain Altitude frame details:

Rocky Mountain Bikes 2021 Altitude, angle

The Altitude has seen a top-to-bottom redesign for 2021. The new Altitude has an edgy, streamlined tubing profile, which helps make the front triangle nice and stiff for solid steering. All 2021 Altitudes now offer 160mm of rear travel, and come with 170mm forks. Frames are available in Rocky Mountain’s Smoothwall carbon or FORM Alloy.

The Altitude employs RMB’s Smoothlink four-bar suspension linkage, but the new Altitudes get dual bearings at the chain and seat stays for increased stiffness and durability. All pivots, including the lower shock mount, rotate on shielded bearings.

Rocky Mountain Bikes 2021 Altitude, frame size difference

Size Specific Wheel Sizes

With the new Altitude, RMB decided to offer different wheel sizes based on frame size. Small frames ride on 27.5” wheels, Mediums get the option of 27.5” or 29”, and Large and XL frames come with 29” wheels only.  The small frame has a dipped top tube with a lower standover height, where the Medium frames’ top tubes are straight, giving them an equal standover height to the L and XL’s.

Aside from size-specific wheels, Rocky Mountain also sets up their bikes with size specific shock tunes. Their Smoothlink suspension aims to provide a supple initial stroke, a supportive mid-stroke and a progressive end stroke, and RMB ensures all riders get their intended ride qualities by matching appropriately tuned rear shocks to every different frame size. Also, the XS and Small frames were specifically designed and tuned around a shorter rear shock.

Rocky Mountain Bikes 2021 Altitude, adjustable dropout

Another new feature on the 2021 Altitude is chainstay length adjustment. A flip-chip added to the dropouts shrinks or extends the rear end by 10mm, so riders can choose between a more agile, playful ride or opt for more high-speed stability. To keep the brake caliper properly positioned, Rocky Mountain supplies their own brake mount that simply flips over to work in Short or Long mode. This does mean you’re stuck with a 180mm rear rotor, but that should be ample for 99% of riders.

Rocky Mountain Bikes 2021 Altitude, Ride 9 chip

The Altitude features Rocky Mountain’s Ride 9 Chip, which allows you to make minor geometry adjustments and fine-tune the bike’s shock rate.  Having ridden this system before, I can say the nine positions are not overkill – each increment is noticeable as you dial in your ideal shock rate.

2021 Rocky Mountain Altitude geometry:

Rocky Mountain Bikes 2021 Altitude, geo chart

The frame’s angles only change by about one degree from position 1 to position 9, so you don’t get a wide adjustment to the Altitude’s geometry. The chip has a significant impact on how the shock behaves, so it’s important to play with it and find the position that works for your terrain and riding style.

Check out the chart above for all the Altitude’s specs, but some key geometry figures to note are fairly slack head tube angles from 64.4 – 65.5 degrees (the same for both wheel sizes), and pretty steep seat masts at 75.4-76.5 degrees. Reach on a Medium frame ranges from 449-461mm, and the adjustable chainstays range from 425-439mm on the 27.5” bikes and 436-449mm on the niners.

Rocky Mountain Bikes 2021 Altitude, bolt-on shock mount

Right away I noticed the Altitude’s new bolt-on shock mount. This could be a clever future-proofing move from RMB, as they can now revise and update the Altitude’s suspension kinematics by altering that mount instead of modifying the whole front triangle. The bolt-on mount is only on the carbon Altitudes.

Rocky Mountain Bikes 2021 Altitude, chain guide and shield

I always liked Rocky Mountain’s low profile Spirit Guide chain guide. However, the Altitude features something new – RMB has designed the ‘Canadarm’ (nice Canadian space travel reference there) to hold up One-Up Components’ V2 top chain guide. The Altitude also offers the ‘Canadian Shield’ (a nod to Canada’s geography), a slick little cover that keeps your cables clean as they run from the front triangle to the rear stays. As Bikerumor’s Canadian contributor, I chuckled at RMB’s clever accessory names, eh!

Rocky Mountain Bikes 2021 Altitude, cable routing

The Carbon Altitude frames feature fully guided internal cable routing, where the alloy frames have large easy-access ports. RMB’s routing setup is internationally-friendly, allowing the rear brake to be set up on either side.

Rocky Mountain Bikes 2021 Altitude, chainstay guard

The 2021 Altitude uses a new derailleur hanger from RMB, but in Long mode the Altitude can also run SRAM’s new universal hanger. The frame is protected with a shuttle guard, lower down tube protector and a noise-cancelling chainstay guard.

Component notes:

Rocky Mountain Bikes 2021 Altitude C 99
*Here’s a glance at the top-spec Carbon 99 model, in all it’s wireless glory!

There are enough different models within the 2021 Altitude lineup that summarizing all their component specs would be exhausting, so check out Rocky Mountain Bikes’ website for all the particulars. Here are a few notes about the new models;

Forks on the 29” Altitudes are either 44mm offset (Fox) or 42mm (RockShox).  Tire clearance is up to 29×2.6”, and the frame will fit chainrings from 30-36t. The 27.5” frames run forks with 37mm offsets, and they can accept 30-34t chainrings. Tire clearance goes up to 2.6”.

Rocky Mountain Bikes 2021 Altitude, carbon frameset
*Images c. Rocky Mountain Bikes

RMB does provide weights for their bikes, so here’s a few for reference: The 29” Carbon 90 Rally Edition weighs 32.3lbs, and the 29” Alloy 70 complete weighs 35.4lbs (medium frames). The 27.5” versions of each bike come in roughly a half pound less than their 29er counterparts. A Large 29” carbon frameset with a Fox X2 rear shock weighs 7.49lbs.

Carbon Models:

  • Carbon 99 – $9999
  • Carbon 90 Rally Edition – $9099
  • Carbon 70 – $6999
  • Carbon 70 Coil – $6999
  • Carbon 50 – $5499
  • Carbon frameset – $3699

Aluminum Models:

  • Alloy 70 – $5249
  • Alloy 50 – $4299
  • Alloy 30 – $3499

Initial Ride Impressions:

Rocky Mountain Bikes Altitude, Steve Fisher ridingHaving ridden a few Rocky Mountain Bikes now, I can say the brand succeeds in giving their full-suspension models similar ride qualities. The Altitude immediately reminded me of the Instinct BC edition I tested a few years ago, and indeed is the closest thing to it in RMB’s 2021 lineup.

RMB’s suspension seems to be quite soft on the initial stroke, which will produce some pedal bob but doesn’t allow the bike to bob very far. It’s enough to offer sensitivity, but not soft to the point where your pedaling efficiency is seriously hampered. That said, I always use the rear shock’s Climb or Firm mode for uphill grinds on Rocky Mountain’s bikes. I find the rear end still moves enough to track well over technical trails, but firming up the shock makes the bike feel more supportive at the pedals.

Things ramp up a bit for mid-stroke, giving Rocky Mountain’s bikes a playful, poppy ride. I always seem to launch off bumps really well on a Rocky – the linkage responds well to quick hits and gives you plenty of pop. Closer to end stroke, the Altitude ramps up so much that I’m still tuning mine to give me all its travel. The Altitude is progressive enough that I’m sure much heavier riders could achieve the tune they need.

The Altitude’s frame geometry is solidly enduro but it doesn’t have that ‘big enduro rig’ feel like Trek’s Slash or Rocky’s own Slayer. It feels more like a long-legged trail bike, and its frame is (aesthetically at least) on the leaner side. RMB did ensure the Altitude’s front end was good and stiff, and it is more solid than it might look as you plow through rough terrain.

Rocky Mountain Bikes 2021 Altitude, actual weight

I am a fan of keeping weight down, and the complete Altitude Carbon 70 comes in at a very reasonable weight for a long-travel enduro 29er: RMB lists 31.9lbs for a Medium, mine weighed 32.25lbs with pedals.

That’s all I have for review notes at this point, but I’ll be riding the Altitude and playing with all its adjustments as I piece together my long-term review. In the meantime, check out Rocky Mountain Bikes’ website for full details on the 2021 Altitude lineup.

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