Rocky Mountain Introduces MX Mount for Altitude and Altitude Powerplay

Jul 13, 2022
by Rocky Mountain  

We're excited to introduce the MX Mount for our Altitude and Altitude Powerplay platforms, which allows for a quick and easy conversion to a mixed wheel size setup while maintaining similar geometry to the stock platforms. The MX Mount is available for purchase for $136 USD on and is compatible with all Altitude Carbon 29" models, and Altitude Powerplay Carbon 29" models.

The MX Mount

Altitude 29

The Altitude combines decades of racing experience with our latest technology innovations that allow you to ride harder and faster than ever before. With the new Altitude MX Mount installed, you’ll be able to use a 27.5” rear wheel to help corner faster, ride more playfully, all while giving you a bit more clearance when you’re behind the saddle on a steep, technical line.

When you install the Altitude MX Mount, you will increase the travel of your Altitude or Altitude Powerplay while also lowering the rate curve. This means you might have to increase shock pressure or go up in spring rate to achieve proper sag and suspension feel.

The Altitude MX Mount is easy to install and maintains similar geometry to the regular Altitude 29. The Altitude MX mount is designed to be compatible with Positions 1-5 of our RIDE-9 adjustment system only. Position 5 is the “Neutral” position, and the bike becomes incrementally slacker and more progressive as you move towards Position 1, the slackest position. Positions 6-9 have less clearance between the back of the seat stay brace and the seat tube and are incompatible with the use of the Altitude MX Mount.


Altitude Powerplay

The Altitude MX Mount is easy to install and maintains similar geometry to the regular Altitude Powerplay. The Altitude MX mount is designed to be compatible with Positions 1-4 of our RIDE-4 adjustment system only. Position 4 is the steepest position, and the bike will become incrementally slacker and more progressive as you move towards Position 1, the slackest position.

Altitude Powerplay suspension curve with MX Mount installed



bigquotesWith the MX Mount, I’m more comfortable on my bike than ever. And because of that I feel like I’m now able to hit my race speed.Andréane Lanthier Nadeau

ALN could be seen running a prototype MX Mount during the 2021 Enduro World Series season.


bigquotesI like to bring a creative approach to the trails, search for alternate lines, look for things to double up. Ultimately, I like the extra clearance from running my Altitude with mixed wheel sizes.Thomas Vanderham



Thomas Vanderham rides the 2022 Altitude Powerplay.
Not just limited to the Altitude, the MX Mount is also compatible with its motorized counterpart, the Altitude Powerplay

Thomas Vanderham's custom Altitude with the MX Mount installed

For more information on the MX Mount, visit

Video by: @scottsecco
Photos by: @Margus

Author Info:
RockyMountainBicycles avatar

Member since Jan 14, 2011
144 articles

  • 92 0
 did anyone else not read a thing due to the killer photography? kudos to whoever is behind the lens
  • 14 0
 Came here to say, that shot in the middle with the huge boulder and the fog looks like something from the pic o' the year contest.
  • 16 0
 Margus Riga just always kills it. You've definitely admired his photography before without ever knowing it was him.
  • 4 0
 The pics are very reminiscent of the stuff on NSMB, which is great
  • 1 2
 Photographer got it right, RM clearly didn’t so needed a new mount.
  • 18 0
 Modular mounts is an interesting idea. There's a lot of potential for after-market modifications from other brands or small companies.
  • 4 3
 Like a wants to sell 10 mounts a year kinda small?
  • 5 0
 @justanotherusername: Or the ones that make other after market links like Cascade. It's just something else they could potentially produce.
  • 3 0
 @justanotherusername: I wonder what Cascade Components moves for their Transition/Forbidden links. That must be a pretty small market.
  • 1 1
 @justanotherusername: 9, I don’t need one.
  • 1 0
 @schili: well, selling a couple hundred at their high prices isn't too bad
  • 16 0
 I do not unserstand the graphs but those pictures are absolutely beautiful!
  • 13 0
 That orange coil in the dark woods - porn.
  • 5 0
 On an almost entirely unrelated note; I often wonder why this suspension configuration (what I think of 'bottlerocket' spec, i.e. shock under the top tube, pivots by the BB and at the seat tube / top tube junction) isn't the go to choice for most bikes?
There's no worries about where to put a water bottle, the seat tube is uninterrupted, it can be single pivot, ABP or 4 bar, you can have a shock with a long shaft length etc.
  • 4 0
 limits to top tube positioning. Standover height for smaller riders. but other than that, it is a good choice. (someone is going to say low center of gravity, but that's a BS argument)
  • 3 0
 Mainly top tube strength, and leverage ratios are differently affected by pivot changes. There's a reason a lot of bikes have gone for the 'super strong bb/main pivot/lower shock mount area with a lighter weight tubeset' route. Might look like a session, but the session is good at what it does.
  • 1 0
 Because the session 4 bar is pretty good As is VPP This right here is an XC configuration made to work somehow
  • 4 0
 Between ride-9, modular mounts, and pretty infallible quality (at least I haven't met someone who mangled a rocky) I'm thinking Rocky Mountain might be where I send my sheckles next
  • 2 0
 Two seasons in on my Altitude and it has been great! Good quality, great ride and it is as fun in the bike park as on the local gnar or mellow trails.
  • 3 3
 Get ready to send them a shitload more sheckles than a lot of other comparable brands.
  • 2 0
 I recently sent my sheckles to RM for a new Instinct and have not been disappointed. It absolutely rips. The Instinct and Altitude are the same carbon frame now so that modular mount really opens up the possibilities.
  • 2 0
 Infallible quality, other than the 12 instinct frame failures and subsequent recall.
  • 1 1
 Yeah, that's become a trend over recent years. They are bloody expensive and often very bad value for money. But if money isn't an issue you can't really ever go wrong with a Rocky.
  • 1 0
 @eh-steve: lol I ain't riding no instinct tho :wink: direct sale (commencal) is usually my beat but I am pinching those pennies for a dream build
  • 1 0
 Totally biased RM fanboy checking in. Yeah Rockies cost more, but you won't care when it rides like a dream. Both my 2018 Instinct and 2021 Altitude have the magical "X-factor" in spades.
  • 3 0
 Thanks Rocky for setting a positive example! This is the way all Manufacturers should handle this. Screw bikes that are mullet only or 29er only. The rider should be able to choose what they want to ride.
  • 6 2
 Quick note,
You can pretty much put a 275 wheel on anything…
Don’t sweat the slight geo changes so much, slap one on, and give it a try.
  • 2 3
 @onawalk: seems to me if you change to 27.5 front and rear, geo doesn’t change?
  • 2 0
 @kingbike2: bb will be lower, so there’s that to deal with if you’re wanting to swap to 275 wheels.
Was addressing the OP’s comment about mullets. We seem to get fairly caught up in numbers on paper, give stuff a try, see what it’s like, don’t be so concerned with what some article states about optimal seat angles, etc.
Willing to put a 6-pack on the idea that the stated geo for most bikes are very different from reality.
  • 4 1
 @onawalk: BB heights are already pretty crazy low these days. I'd say it would only be worth the gamble if you already have a compatible 27.5 wheel kicking around to try, otherwise most people would end up too low and selling the wheel they just bought.
  • 3 0
 @onawalk: I'd disagree. With many of these new 29er long-travel Enduros and Super Enduros having like 30mm or more of BB drop, you'll start scraping the ground if you put in a 27.5 rear wheel. In most cases you really need something to counteract the BB drop. Sure, it could be done and it would probably work somewhat. But on my Canyon Torque I'd get constant pedal strikes. I already feel like the BB absolutely is as low as can be with a 29er rear wheel.
  • 1 0
 @mammal: Have you tried it?
  • 2 2
 @Muscovir: disagree with what,
Trying a 275 wheel on your bike?
So you’ll hit a pedal on the ground a touch more often, Jesus.
Who cares, give it a try and see what it’s like, stop worrying so much.
How much have you calculated that a 275 wheel is going to change your bb drop?

If I ballpark some measurements
Totque 275 has a bb drop of 14, 29 is 30
275 wheel dia is 584, 29 is 622
So half of each is 292 and 311
So bb height on a 275 is 292-14=278
Bb height on a 29 is 311-30=281, so the 29 is 3mm higher
SO in theory, if I swap a 275 wheel on to a 29 torque frame, I’m 16mm lower
Add to that that the chainstay is 440 on a 1250 wb, so FC is 64% of overall (med frame dimensions, RC is the same across all sizes, so on a large or XL frame it has less impact)
So like 10.5mm difference overall I think.

I could be wrong, I’m doing this napkin math in my head as I’m typing.
I realize it’s lower, but I’m pretty sure you’ll be fine if you tried it.
  • 3 0
 @onawalk: your math is slightly off, you used ERD, but would need actual tire diameter. Either way, throwing a 27.5 wheel on a 29" bike will do the roughly the following according to some online calculators:

slacken the head and seat angle by about 1 degree
lower reach by 10-11mm
drop the BB by about 12-13mm
raise the stack by 7mm

Should technically be similar across any bike, only thing that will change the numbers is depending on the overall height of the tire used. Can mess with this here:

Could get away with it if your bike has 175mm cranks, and going with 165mms to offset the lower BB. I have 165mm cranks on my bike and it was the best upgrade I've ever done. I had pedal strikes constantly with 175s and I almost never hit them now.
  • 1 0
 @onawalk: No but know the ball-park change in BB height because I've done the calculation for other bikes. I also know from experience that a difference of over 10mm in BB height is massive, when it comes to cornering feel and likelihood of pedal/rock strikes.
  • 1 0
 @onawalk: I can't ride a mullet setup - where would I put the used front 29er tire and which tire should I use on the back without having a preworn front 27,5 tire?
  • 1 0
 @Ryan2949: so you’re saying my math was off by about 1.5mm…
I don’t think it’s a question of whether or not you could get away with it, cause clearly you can.

My point is, we (me included) stare at numbers and think they’re set in stone. Stop over thinking it, and give it a try, you’re not gonna die.
Some people get real hung up on these things.

Again willing to bet that most of the posted numbers on geo charts are out from what they’re “supposed” to be anyway.

@mammal ease up champ, unless you’re racing at the real sharp end of some race series stop taking it all so serious.
this massive difference you’re thinking of, I’ll bet it’s similar to changing from a worn Dissector, to a new DHR, no one blinks at that.
  • 2 0
 @onawalk: Sure, that's fine if you don't notice 10mm of BB height difference, but it makes a huge difference to many, and it's not comparable to swapping tires.
  • 1 0
 Your gonna wet your self when you what Nicolai does with there g1 and saturn 16
  • 1 2
 @mammal: Going back to my original point, we seem to get caught up on numbers, and use them to justify our belief, rather than letting our imaginations take the reigns and giving things a try.
You made my point clear, when you said you’d done the calculations, so you knew you were right, that it wouldn’t work for you, and your bike (might be true, I can’t tell you for sure)
I’m just saying, the printed numbers have some inaccuracies built into them, so don’t take em as gospel. Dont be so frightened to give something a try, and try to keep an open mind when doing so.

Swapping from a 2.4 DHR, to a 2.4 Dissector has a huge visual difference, and “feels” like it’s a much smaller volume tire. I don’t have a DHR to verify, but I might swing into the local shop and see what it measures out as. I’ll compare it to my really well worn Dissector, but I’m willing to bet a 5mm difference at least, so theres half the bb height difference right there.

I’m not saying you’re wrong, or that your beliefs aren’t valid,
I just think that all of us (me included) have the tendency to dwell on numbers to make valid our beliefs.

Add to that, now I’m making an assumption here, your bike has a flip chip, that you’re prolly riding in low, there’s 8mm of bb height adjustment there, so you have the ability to compensate right at your fingertips
  • 1 1
 @mammal: buckle up my man,
Took actual tire measurements this morning.
The difference between my moderately worn out 29 x 2.4 Dissector, and a new DHF (29x2.5) is 9mm, so 4.5mm effect on height (in theory)
Same difference with a 29x2.4 DHR.
So, based on your comment that 10mm is a significant change, 4.5 should be something to you as well.
@Ryan2949 actual HA change on my bike with a 275 wheel is marginal, .3-.4 of a degree. Prolly well within spec differences of frames and forks, etc.
So again nothing major.
I’m willing to bet, that most wouldn’t be able to differentiate between the geo changes, unsure about the wheel change.

In closing, I believe you can easily put a 275 wheel on the rear of your bike without any sort of adverse handling changes. With so many different tolerance allowances, and bits and pieces going on, I don’t think many of us would notice the geo changes.
I say give it a try if you want, stop worrying about it.
  • 1 0
 @onawalk: Lol, you know that 10mm of BB height is not the same as 10mm axle drop, right? So that 4.5mm difference you measured is how much the REAR AXLE has dropped due to changing tires, but the BB has likely only dropped about 2.5mm due to that change, because geometry. So yes, 2.5mm of BB height is probably not a huge deal to most. Wow, glad I buckled up for that.
  • 1 1
 @mammal: good catch, a little tongue in cheek on my part
Mostly just illustrating that we make changes without a thought sometimes, and others we believe are going to have drastic effects.
If 2.5mm isn’t a big deal, how much is, you believe 10mm makes a huge difference, so 2.5 should make a moderate difference?

I think we get caught up on the numbers to justify our belief, rather than basing our belief on what we try.

Like a $150 investment on a used 275 wheel is prolly not going to be too big a deal, which you can then go and flip again if you don’t like it.
  • 1 0
 @onawalk: Dude, you've explained what you're trying to get at about 3 or 4 times now. "Prolly" time to wrap it up, no?
  • 1 1
 @mammal: ahhh,
You just like to spout on about being an authority on things, without your thoughts being challenged.
Cool man, keep being you.
  • 1 0
 @onawalk: I have experience (not thoughts) that I was trying to share with the OP. That's it. Move on.
  • 1 0
 @mammal: you responded to me, not the OP.
You stated that you hadn’t tried it, that they were just your assumptions.
I provided fairly clear and easy to understand reasoning as to why your original statement might not be valid, and that seems to have rubbed you the wrong way a bit. That’s cool.
I imagine someone along the way told you it wouldn’t work, and you went with it. The. Some clown on the internet challenged that, and you’re re-thinking your position.

You could have just ignored any of my responses, and it prolly would have died, but you’re still here, reading and responding so you’re interested.

Swing by, let’s throw a 275 wheel on her bike, and do some blind testing on trails you’re unfamiliar with, see if it works. It’ll be cool
  • 1 0
 @onawalk: Sorry, you're right I replied to you, but only to provide context to the OP, because I actually don't care if you have alternative thoughts about this. I said I hadn't tried a 27.5 on a 29er, but that I knew the geo differences from calculating the BB difference before, and that I had experience with a BB drop of slightly more than 10mm ( which is what we're talking about here). On the contrary, you haven't tried it either, don't seem to know any better from experience, and are trying your best to prove multiple people wrong with bad math/observations. I certainly wouldn't want to waste money based on that opinion, and hopefully the OP doesn't.
  • 1 0
 @mammal: I think my math was fairly solid, showed that there is approx 10mm bb drop from going to a 275 wheel, which based on typical manufacturing standards is prolly negligible.
Not trying to prove anyone wrong, mostly just trying to point out that it’s not going to be that big a deal, and most people make to much fuss about it.
And you’re right, I haven’t tried it, not sure its going to make much difference to me one way or another, but again, giving it a try ain’t gonna hurt.
I’ve got a spare hub lying around, that needs a wheel, maybe I’ll lace up a 275 to give it a go.

What was “bad” about my math or observations?
  • 1 0
 @onawalk: The bad math/observations was you're "buckle-up" comparison, trying to discredit my experiences of riding bikes with a 10mm BB height difference. But actually, you were talking about a 2.5mm BB height difference.

"mostly just trying to point out that it’s not going to be that big a deal, and most people make to much fuss about it." YES, I know, you've said this 5 or 6 times now. Go try riding a super low BB if you like. I've tried it, explained my findings (which you don't have to agree with). Bikes are fun, but repeating myself isn't, so this is done.
  • 1 1
 @mammal: the math wasn’t bad, and as I noted I was making a point about how much just a tire change can make, not overall bb height.
The OP never made mention of what bike they rode, so you just threw uneducated advice out there to voice your opinion.
A stumpy EVO, which is by all rights fairly popular, and seems to be a hit, has a bb height (in medium and low, which is where I’m guessing most have it) of 333, which is 12mm lower than my Sentinel (which was also a fairly popular bike). Gets even lower in slack and low-331.
So I could easily put a 275 wheel on my Sentinel and prolly not have any issue. I still maintain that most could, a quick look at some geo charts puts most bb heights at 340-350, so plenty of room to drop the 10mm by swapping to a 275 wheel to give it a try.

Hell even your Ripmo could swap out to a 275 rear wheel without too much fuss, (cant fix that bent too tube though, just joking)

As you said, bikes are fun, so maybe stop trying to kill people’s buzz! (intentional)
  • 6 0
 Nice “We scored the best URL” Flex.
  • 1 0
 Old news, though. Literally a very long time ago that that domain name was available, and they've been using it ever since.
  • 4 0
 Suspension Rate is just the inverse of the Leverage Ratio and it tells the same story, but FFS stop using it.
  • 1 0
  • 2 0
 Interchangable wheel sizes. We have the technology! I don't claim to understand the graphs but the overall principle is easy to understand so I know this a positive thing for the consumer.
  • 1 0
 Yeah, this. If Scott can do it, so can the other big brands.
  • 1 0
 Hey rocky, do you have any documentation on how much travel increases/decreases on your Ride9/Ride4 stuff? When its all mapped out in the suspension software, its not insignificant.
  • 4 0
 Some french website I can't remember had it at 6mm of change in either direction and the neutral position gave you the advertised travel on the bike. The change in suspension curve also kind of compensates for the added or lost travel.
  • 1 0
 Ive got the info from rocky on the slayer. shoot me a pm
  • 3 0
 I just wish Rocky had engineered the alloy frames to accept these modular shock mounts like the carbon frames.
  • 2 0
 Agreed. I'm not opposed to buying a carbon bike (next frame will likely be carbon due to alloy not being an option), but I still prefer alloy. I'll spend the savings on better components.
  • 1 0
 Mullet works great on the new slayer too. Just put it in position 4 on the ride 4 chip. Beautiful pics, I didn't read any of it till I was done starring at the pics.
  • 1 0
 @RockyMountainBicycles is the wheelbase length on the MX Mount overview page based off the short or long rear centre length?
  • 1 0
 Sick. Now how about one for the Reaper? Need to mullet out my son's kiduro rig.
  • 3 0
 You've got one already in the Ride9 chip, iirc. Just set it to the steep setting (or 5 or 7) and throw in the 26" front wheel (24" in the back).
  • 1 0
 @Svinyard: Thanks. Actually thinking more 27.5/26
It may be a way to get another season out of the bike... he's growing fast.
  • 2 0
 @MT36: the fork will handle a 275 wheel.
  • 2 0
 @MT36: Need a different frame. The reach on that bike actually shrinks when you go from 24" to 26". So in the 26" version the reach is about the same as a Transition Ripcord 24". Fitment gets even more wonky if you mullet it to 27.5 likely as reach will shrink even more. Best to just grab the inevitable new frame/bike now as things aren't going to get cheaper. A mullet 26/27.5 is pretty rad tho, so I'd try to stick with that. I've got a 2020 Altitude XS built up with 26" wheels for my oldest son and am about to Mullet it with the 27.5 on the front as well.
  • 1 0
 @Svinyard: Cool. I think the thing to do will be get the next frame/bike for him. In all practicality, I don't know if getting the 27 in front is thing to do... could really change the characteristics in a not good way.

I am also looking at the XS altitude for him as the next bike.
  • 1 0
 Mike Levy's female version
  • 1 4
 They should probably include a "Ride-5" chip to lock-out those incompatible positions. Would save on some support calls and warranties claims _when_, not if, someone forgets and accidentally puts it into a position where they might be smashing frame bits together.

Actually, I hope for their sake that their lawyers' retainers are paid up, since they're selling a first-party official modification that can actually cause frame damage in some configurations and the only thing preventing those configurations is "you should've known better".
  • 1 0
 It's a Canadian company.
  • 2 0
 Weird that the ride 4 chip is identical in size if I remember as the ride 9, but just doesn't have the center position change. They should just send out a ride 4 chip with every one of these.
  • 1 0
 needs more adjustability ...
  • 1 2
 +40% progression! Man that is going to ride like utter garbage!
  • 2 0
 Haha man, you don't even know... RM's ride like a DREAM with a coil, likely the absolute BEST bike for a coil hands down.
  • 1 3
 When is the next generation altitude coming??
  • 1 0
 They just released this one last year...
  • 2 4
 Now if they could come up with a way to fix the front end too

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